LIBRARY 0.3 ^ AUGg8 1962 II. J. »««we: * in/w.ii« BEl.TSViLlL BRANCH

PROTECTION OF

AGAINST NUCLEAR ATTACK

guide for agricultural leaders

AgTicOlture Handbook No. 234 AGRICULTURAL RESEARCH SERVICE • U.S. DEPARTMENT OF AGRICULTURE PROTECTION OF

3 guide for agricultural leaders

Agriculture Handbook No. 234 AGRICULTURAL RESEARCH SERVICE " U.S. DEPARTMENT OF AGRICULTURE

Washington, D.C. 1962

For sale by the Superintendent of Documents, U.S. Government Printing Office Washington 25, D.C. - Price 30 cents PREFACE If a nuclear attack were to be made upon the United States, all segments of our population and of our economic structure would be affected. Many of the problems created would be similar if not identical among the various segments. Some of the effects would be peculiar to each segment according to its needs and responsibilities. Thus, agriculture would share the Nation's total difficulty and still be faced with special problems. The United States Department of Agriculture, in cooperation with other agencies of Federal and State governments, is respon- sible for helping to develop means by which farm people could cope with these special problems for their own protection and to maintain farm production in times of emergency. In fulfilling its responsibility, the Department partici- pates in devising active defense and implementing actual protective programs, in conducting research to provide the knowledge on which these programs are based, and in keeping farm people and agricultural leaders informed about them. One of the major parts of the defense plan being developed against nuclear warfare is aimed at reducing potential hazards from radioactive fallout. This handbook describes what is known about the effects of fallout on agriculture and what defensive measures can be taken against them. The infonnation, including tables and denial times, is based on emergency conditions, not those prevailing in times of peace. Some of the terms used may be unfamiliar because the widespread applica- tion of nuclear science is relatively new. However, many of them are rapidly becoming a part of the Nation's everyday vocabulary. A glossary is included in this publication to aid in a fuller understanding of such terms.

Ill CONTENTS

Page Page Nuclear Explosion 1 Protection Against Internal Radiation Area of Destruction 1 From Fallout—Continued Fallout Formation 2 Radioactive Iodine, etc., in Food—Con. Area of Severe Fallout—Surface Detona- Radioactive Strontium 19 tions 2 Radioactive Strontium in Food 19 Residual Eadiation and Fallout 2 Croplands Contaminated by Fallout 21 Radioactivity Not Transferred From Use of Contaminated Land 21 Fallout 3 Reducing Strontium 90 Uptake With Gamma and Beta Radiation 4 Soil Amendments 23 Radiation Hazards From External and Croplands Contaminated by Irrigation Internal Sources 4 Water 23 Protection Against External Radiation Reclaiming Contaminated Land 24 From Fallout 5 Decontamination by Removal of Effect of Distance 5 Ground Cover and Crops 25 Effect of Time on Intensity of Radiation _ 5 Decontamination by Removal of Sur- Effect of Shelter and Shielding 6 face Soil 25 Shelter 6 Other Methods of Decontaminating Radiation Attenuation 7 Soil 25 Decontamination 8 Reclaiming Soil by Deep Plowing 25 Work Schedules in Fallout Areas 9 Effects of Radiation on Plants and Handling Livestock 10 Seeds 26 Poultry 11 Summary of Effects of Fallout on Agri- Shelter 12 culture 26 Irradiation Effects on Animals 13 Shelter 26 General 13 Food, Feed, and Water 26 Sexual and Genetic Effects 13 Maximum Work Times 26 Embryologie Effects 13 Food Decontamination 26 Protection Against Internal Radiation From Reclaiming the Soil 26 Fallout 13 Glossary 27 Radioisotopes Causing Internal Radia- Appendix A—Measurement of Fallout tion 13 Radiation 30 Protection of Food, Feed, and Water__ 15 Appendix B—Protection Factors 34 Food 15 Appendix C—40 Cow Dairy Barn and Feed and Water 16 Family Fallout Shelter 36 Radioactive Iodine and Radioactive Trench-Type Shelter Arrangements 37 Strontium in Food 17 (A, B, C, D) Roofs for Trench-Type Radioactive Iodine 17 Fallout Shelters 37 Reducing Iodine 131 Contamination (E, F) Fallout Protection in Buildings_. 37 of Food and Dairy Products 18 Publications and Films 40

IV PROTECTION OF FOOD AND AGRICULTURE AGAINST NUCLEAR AHACK

A guide for agricultural leaders

The development of nuclear energy has created Researchers are developing knowledge that will a new and uncertain element in man's world. On help to provide this protection and those in the the one hand are the rapidly expanding liorizons U.S. Department of Agriculture are taking part. of progress made possible through the peacetime The study of nuclear weapons is relatively new uses of this new form of energy. On the other and the usual techniques of research cannot al- hand is the possibility of damage or destruction ways be applied because of obvious restrictions of man and his possessions through the use of nu- on the conditions of testing nuclear weapons. It is clear weapons if world peace cannot be main- therefore understandable that not all of the tained. needed information in this field is fully developed One of the important defenses against wide- today. However, studies are extensive and the spread destruction from nuclear weapons is a well- fund of knowledge is growing. informed population, armed with as much knowl- One of the problems that is being widely studied edge as possible about protection and survival in to help agriculture survive a nuclear attack is the case of attack. Agricultural leaders and farmers effects of radioactive fallout and what can be done are responsible now, in time of peace, for develop- to preA'ent or minimize them. In approaching this ing a capability of the Nation to protect its people problem, we can start with a brief description of and the ability to produce food and other products the nuclear explosion itself. necessary for existence. NUCLEAR EXPLOSION

A nuclear explosion results in four destructive instantaneous at the moment of detonation, but the phenomena: (1) Blast, (2) light and heat radia- fourth (residual radiation, especially from detona- tion, (3) initial ionizing radiation, and (4) resid- tions on the ground) produces its effects later, ual ionizing radiation. The first three are almost longer, and over a wider area, as fallout. Area of Destruction

The area of destruction resulting from the blast, Field tests have indicated that a 5-megaton nu- heat, and initial radiation will vary with the size clear bomb exploded on the surface of the earth of the weapon, the height of the explosion, and would cause severe destruction to residential build- to some extent with the terrain and atmospheric ings out to about 6 miles from the point of detona- conditions at the time of the explosion. tion. Similar destruction from a 20 megaton de- The size of the weapon is measured in terms of vice would extend out almost 10 miles. The heat its total energy release compared with the energy from an 8-megaton bomb exploded on the earth's released by TXT (trinitrotoluene, a nonnuclear surface might set fires to easily ignitable materials explosive) when it explodes. For example, a 1- during the first few seconds after detonation out kiloton nuclear bomb produces the same amount to about 25 miles on a clear day. If it were ex- of energy as the explosion of 1 kiloton (or 1,000 ploded 2 to 3 miles above the surface of the earth, tons) of TNT. A 1-megaton bomb has the energy its heat would cause fires at somewhat greater equivalent of 1 million tons (or 1,000 kilotons) of distances. TNT. The earliest nuclear weapons released In general, the height of the explosion can be roughly the same quantity of energy as 20,000 tons considered in one of three classifications: (1) Air (or 20 kilotons) of TNT. The energy release of bursts, (2) surface bursts, and (3) subsurface the large bombs developed since World War II bursts, the last one consisting of underwater and ranges from kilotons to many megatons. underground bursts. Obviously, whether the blast occurs hipfli in the air, at or near the surface of ^.^^ example, a $v.T-fnr.o o^plpoi^r, c„T^^„x^ed by the fjround or water, underjiround, or underwater nigh hills or mountains might damage a more lii"" affects the area of damage. ited area than one on a broad flat iilain. Wmd Elements of the terrain such as mountains and direction or velocity and rain also influence the hills also affect the blast and fire damage area. extent of fire damage. Fallout Formation

"\^nien a nuclear explosion occurs close to the Some radioactive materials are scattered on the ground and the fireball touches the surface, large ground locally and some are left at various alti- quantities of earth are vaporized or melted by the tudes as the atomic cloud ascends. The bulk of intense heat of the fireball, and thousands of tons the radioactive fission products, however, are of earth are pulverized by the blast. As the fire- thrust into the stratosphere where they become ball rapidly rises, the ascending currents of air dispersed in the stratosphere with a greater con- carry much of the pulverized earth upward into centration in the hemisphere in which the device the fireball and the developing mushroom cloud, was detonated. where some of the particles are vaporized, some The atomic material in the stratosphere follows are liquefied, and others remain in the solid state. the winds at this extremely high altitude and Part of the vaporized radioactive residue of the travels around the world until it finally descends. weapon condenses in or on the liquefied or solid The return of this radioactive material to the particles of earth. These particles thus become earth is rather slow, carried principally by rain sources of radiation. descending into the troposphere. According to estimates, about one-half of the The residence time in the upper atmosphere material from a surface nuclear detonation will ranges from months to several years. Because of return to the earth's surface as fallout within 16 this long residence time, the radioactive fallout hours. In about 24 lioure most of this local fall- would contain mostly the long-lived isotopes. out, M'hich accoimts for approximately 80 percent The radioactive fallout is composed of long-life, of the total radioactive debris, will have settled. medium-life, and short-life isotopes. The remaining 20 percent of the radioactive mate- rial goes high into the troposphere or passes When the smaller atomic devices are exploded, through the tropopause into the stratosphere. the radioactive materials remain in the upper area When a high-yield nuclear device (megaton) is of the troposphere. The residence time of radio- detonated, the radioactive products resulting active fission particles at this level is measured in therefrom move through the troposphere, the weeks or months. The pattern of distribution is tropopause, and end largely in the stratosphere. not world-wide but largely confined to the hemi- In case of an aerial burst, the fraction of the ra- sphere in M-hich it originates, generally following dioactive products that enters the stratosphere the wind patterns passing through the point of will be larger than that from a surface burst. origin. Area of Severe Fallout—Surface Detonations

Of the fallout that reaches the earth's surface when and where they will reach the earth's sur- m the first 24 hours, the greater portion is in the face. This fallout is a source of radiation that general vicinity of ground zero (point of the earth's surface directly under the detonation). can be hazardous to man and animals in the area It extends from this point to possibly as far as where it reaches the earth's surface. 1,000 miles or more downwind, the distance de- It takes time for fallout to drop from the radio- pending upon wind speed. This downwind di- active cloud, even close to the burst. The earliest rection may differ by as much as 180 degrees from arrival time outside the totally devastated area the direction of the surface wind and may carry might be nearly 30 minutes after detonation. Some the debris at speeds of 75 miles or more per hour. areas within the pattern of severe contamination The initial height of the particles, their size, might not get the fallout for as long as 24 hours shape, and density, together witli the upper air after the explosion. At any particular location it winds and precipitation, will largely determine could continue to fall for hours. RESIDUAL RADIATION AND FALLOUT About 90 percent of tlie energy of a nuclear radiation in fallout. Arbitrarily, residual radia- explosion is released through the blast, light and tion is said to begin about 1 minute after the ex- heat, and initial radiation. The remainino-10 per- plosion. It continues at a diminishing rate for cent of the bomb's energy is expelled asl-esidual years. Tallout

FiGüEE 1.—In a nuclear explosion thousands of tons of material are taken up into the fireball. As the fireball cools, radioactive particles formed from the bomb are fused with particles of dirt and debris to form radioactive fallout. Where it falls to earth depends, in part, on the place of origin, on the size of the particles, and on the direction and velocity of the wind.

Eadiation is emitted by radioisotopes (fission aided eye may resemble dust such as that from a products, and radioisotopes formed by neutron cultivated field, as a fine white powder, or tiny capture) produced by the explosion of the bomb. glassy beads. It can pass into and through matter. Radiation Fallout composition varies with the type of soil can change, damage, or destroy living c«lls through or rock at ground zero, but fallout generally takes ionization (see glossary) of cell constituents. the form of granular sand, glassy beads, or dust, Since fallout contains radioactive fission prod- and is readily distinguished on smooth or polished ucts and other isotopes, it emits nuclear radiation. The fission products condense in and on dust and surfaces, if present in significant amounts. The soil particles. Physically it behaves like dust or intensity of radiation from the fallout produced soil falling onto exposed surfaces. Sometimes, in by a. given explosion varies roughly with the areas of heavy fallout, it is visible and to the un- amount of the fallout. Radioactivity Not Transferred From Fallout

Radiation from fallout does not cause irradi- Fallout as a source of radiation can be compared ated matter, living or inanimate, to become radio- to a lantern as a source of light rays. T^Hien the lantern is in a room, it emits light rays that strike active itself. In considering the effect of fallout various objects. When the lantern is removed, on agriculture, the radioactive contamination in the light rays are gone and the room is dark. In the fallout itself is the principal concern. the same way, when it has been possible to remove the fallout, the radiation is gone and the irradiated ation damage to the-trving matter may pei^^ ' materials are not radioactive. However, the radi- although its effect may not appear until later. Gamma and Beta Radiation

Gamma rays and beta rays are the two most speed electrons. Beta particles can be easily important types of radiation in fallout. Gamma stopped. Several layers of clothing can aid in rays are similar to X-rays. Their danger in fall- protecting against penetration of beta particles. out is greatest soon añer it arrives in an area. However, if a sufficient quantity of fallout gets The rays can travel long distances (many feet on bare skin, beta particles will cause severe burns, through air and several feet through water) and and the effects may be even more serious if suffi- are difficult to shield against. The intensity of cient fallout is ingested or inhaled by man or live- the gamma rays can be reduced only by shielding stock. Some of these isotopes continue to emit with a sufficient mass of material between the beta particles for long periods of time—measured source of radiation and the subject. In general, in years. the denser the material the lesser is the thickness See Appendix A for information concerning required for shielding against gamnia rays. special instruments developed for the detection Beta "rays'' are particles identical with high and measurement of various nuclear radiations. Radiation Hazards From External and Internal Sources

The hazards of ionizing radiation from fallout when the exposure is distributed over long periods to living organisms arise generally from two of time. The concept of the equivalent residual sources: (1) External sources and (2) internal dose (ERD), which takes into consideration the sources. Both are of concern to agriculture : First, recovery processes, is used to allow for differences as a potential hazard to farm people and their in biological effects of exposures between those livestock, including poultry, and second, as a delivered during very short and those delivered source of danger to the consmners of agricultural during longer periods of time. '\'\Tien exposure food products. occurs over a few days or less, the total accumu- (1) Radiation from external sources is a se- lated dose and the ERD will be essentially the vere problem that would be faced during the first same. However, when exposure to radiation is few hours or days following the arrival of the spread somewhat evenly over months or years, fresh fallout on the surface of the land. The the total accumulated dose may be as much as five gamma radiation for a time soon after the arrival times that of the ERD. The ERD is the con- of early fallout is more hazardous than beta radi- trolling factor. ation, since it is effective at greater distances from In evaluating the effect of damage from radia- the source and is more difficult to shield against. tion exposure, biologists estimate that 10 percent As radiation intensity declines, the beta radiation of the exposure is irreparable and that the body from particles in contact with tissue becomes rel- can repair about one-half of the remaining 90 atively more significant. The effects of the radi- percent in a month. The other 45 percent can be ation on man and animals can range from nonde- assumed to be repaired after about 3 additional tectable damage through varying degrees of months. Therefore, the ERD at any time is equal "radiation sickness" to death. Also, radiation to 10 percent of the accumulated dose (the irrep- sickness can block the ability of normal body arable fraction of injury) plus the fraction of mechanisms to fight or overcome infections. the balance of the accumulated dose that has not The amount of radiation that will damage a yet been repaired. It is assumed that recovery living body depends upon the number and type of commences about 4 days after the onset of ex- cells affected and the type of tissue or organ posure and that each day there is repair of about affected. If the radiation damages the cell to the 2.5 percent of the then remaining reparable dam- extent that its ability to function and reproduce age. This rate of recovery may reduce the repa- itself is lost, and if enough cells are thus damaged rable damage to about zero by the end of 4 months' so that it is difficult for surrounding tissues to post exposure. repair or replace the damaged cells, the injury is For example, if a normal healthy adult receivea severe and in the extreme situation may be fatal. a dose of 200 roentgens (see glossary) during the The human body has recovery processes that are first few days of the month, his ERD early in capable of repairing a major portion of the radi- the month would be approximately 200 roentgens. ation injury, except where the dose is so great that Of this amount, 10 percent or 20 roentgens would death occurs within a few days or weeks after the be irreparable and 180 roentgens would be re- onset of exposure. Because of the existence of parable. During 1 month, half of this latter these recovery processes, individuals are able to amount, or about 90 roentgens, would be repaired. survive exposure to larger amounts of radiation Therefore, provided additional exposure could be avoided, the individual's ERD at the end of 1 phase of radiation hazard. month would be 90 roentgens plus 20 roentgens, AH defense efforts or protective measures or 110 roentgens. In this case an exposure of an against radiation or radioactive fallout are di- additional 90 roentgens, if required during the rected at either preventing harmful ionization succeeding month, probably would not incapaci- within living cells or minimizing the radiation tate the individual to an extent requiring medical exposure and efi^ects of ionization. attention. The principal protective measure for man and All but the most important farm operations animals against the external hazard is the maxi- should be postponed as long as feasible in or- mum use of shielding or shelter, allowing time der to take full advantage of the decay of the for the decrease of radiation intensities. radioactivity. Protection against the internal hazard includes (2) Radiation from internal sources may be a all measures to protect food, feed, and water for serious and long-lasting problem created chiefly man and animals from radioactive contamination ; by the consumption of contaminated food and to keep the radioactive materials outside the water and the inhalation of contaminated air. body. One radiological defense objective, there- It is caused chiefly by the isotopes that produce fore, is to attempt to prevent contamination where beta rays which are capable of traveling only possible or, if this cannot be accomplished, to short distances in the body, or gamma rays which minimize the amount of contamination of the food can travel throughout the body, or both. While supply. inside the body the isotopes continue to emit ra- Researchers have developed information on pro- diation which damages the surrounding cells. tection against both external and internal radia- Most food commodities, both plant and animal, tion hazards of fallout. The remainder of this can be contaminated with fallout materials and publication deals with methods of protection for thus can be an internal source of radiation for agriculture, farm families, and consumers of consumers. Much study is being given to this agricultural products. PROTECTION AGAINST EXTERNAL RADIATION FROM FALLOUT

Radioactive fallout would have serious efl^ects four basic elements of protection against external upon agriculture and food production and storage radiation from fallout are distance, time, sliield- in the event of attack with nuclear weapons, bur ing, and decontamination. there are practical methods of protection. The Effect of Distance

Distance is a natural protection against fallout less radiation exposure than the same amount of radiation from external sources. As would be fallout on the same roof 5 feet over your head. expected, the radiation exposure is less the farther This is true because the radiation is reduced in away you are from the source of radiation. Thus, intensity as it moves away from the point of fallout on a roof 20 feet over your head will give origin. Effect of Time on Intensity of Radiation

The lapse of time after a nuclear explosion is their radioactivity. For example, iodine 131 has also a natural protection against the external radi- a half-life of 8 days. Thus, iodine 131 has decayed ation hazard from fallout because of the decay fac- to half its original activity in 8 days, half the tor of radioactivity. The longer it takes the fall- remainder is gone in another 8 days, and so on. out to reach an area, the greater is the time After 54 days, only 1 percent of the radioactivity required for radiation intensity to decrease be- will remain. Strontium 90 has a half-life of 28 cause of decay. years and 1 percent of its radioactivity will remain About 200 different isotopes of nearly 35 ele- after 180 years. ments have been identified among fission products The total radiation hazard of newly formed created by nuclear explosions. The radioactivity (fresh) fallout decreases rapidly at first because of each isotope diminishes or "decays" at a specific it contains many radioisotopes with short half- rate, different for each isotope. Usually the rate lives. The radiation hazard decreases more of decay is expressed in terms of the ''half-life" slowly after the shorter lived elements have lost of the isotope. Some isotopes lose half their radio- most of their radioactivity. activity within seconds after the explosion. In order to estimate the rate of decrease of total Others take days or months or years to lose half radioactivity, an approximate rule may be used.

644700 O—62 Time - Decay

RADIATION t^ l\ TIME (hr.) DECAY INTENSITY

\^^ 1 — 1,000 i/hr

7 1/10 100 r/hr

7X7 = 49 (2 days) 1/100 10 i/hr

7X7X7=343 (2 wks) 1/1,000 1 r/hr

FIGURE 2.—Decay in radioactivity is related to time. For every sevenfold increase in time following a nuclear explo- sion, the intensity of the resulting radiation decreases. When radiation intensity is l,000r/hr 1 hour after an explosion, at 7 hours after the explosion the intensity would be approximately lOOr/hr, or one-tenth of the original intensity.

According to this rule, for every sevenfold in- lOOr/hr (a tenfold decrease from 1,000). In 49 crease in time following an explosion the resulting hours (7x7) or about 2 days, the rate will be down radiation decreases tenfold. For example, sup- pose the radiation dose rate in an area is 1,000 to lOr/hr. In 343 hours (7X7X7) or about 2 roentgens per hour (l,000r/hr) at 1 liour after the weeks, the rat« will be down to 1 roentgen per explosion. If no more fallout occurs, 7 hours hour. Approximately 14 weeks would be required after the explosion tlie dose rate would be about for the radiation dose rate to be reduced to O.lr/hr. Effect of Shelter and Shielding

Shelter The interval between the explosion and arrival of The most important protection against fallout fallout may provide the time required to get the is shelter. In time of emergency it may not be family and livestock under shelter and to cover feasible to evacuate the population because of the water supplies, food, feed, and other critical items. lack of information about where and when bombs A guide for adequate shelter reserve food sup- might explode, and possible sudden and unpredict- ply is contained in Home and Garden Bulletin able shifts in wind direction and velocity which No. 77, "Family Food Stockpile for Survival." would determine the pattern of the fallout. The most critical period of external radiation Therefore, farmers sliould be prepared to provide hazard is during the first 48 hours after a nuclear shelter for their families and livestock, as well as explosion. In an area where the amount of fall- for their food, feed, and water. For humans the out is great enough to have caused a radiation Office of Civil Defense recommends that a shelter dose rate of 1,000 to 3,000 roentgens per hour within 1 hour after the detonation, total loss of be designed to provide a protection factor of at people and livestock without shelter must be as- least 100. (It is recognized that shelter for the sumed. If people and animals can stay within a large lierds of range animals may not be possible.) good underground shelter for the first 2 or 3 days. deaths from radiation can be reduced. The more shielding effect. Examples of barriers in struc- effective the shelter and the longer it can be mam- tures are walls, floors, and ceilings. tained, the greater the reduction in death rate and Geometry shielding is determined by the extent other harmful effects of radiation. of the fallout field affecting an individual, and his Studies on air intakes for shelters indicate that distance from it. air ducts with two or more impinging surfaces, Here is an example of tlie geometry shielding that is, baffles, in the ducts will remove about 95 effect : percent of the particles from the incoming air. If two buildings are of the same height and simi- lar construction, but of different area, the protec- The opening of the intake, however, should be pro- tion from ground contamination would be greater tected from falling dust and faced downward. on the first floor in the building with the larger Where forced-air shelter ventilation is em- area. ployed, the design of the air intake and ducts On the other hand, if two buildings are of equal should conform to that of the Office of Civil De- area and similar construction, but differ in height, fense regulations. protection from roof contamination would be greater on the first floor of the higher building. Radiation Attenuation The combined effects of barrier shielding and Gamma rays are partially absorbed and reduced geometry shielding result in a shelter "protection in intensity (attenuated) as they pass through any factor." This term is used to express the relative material. Therefore, shielding of any type gives reduction in the amoimt of radiation that would some degree of protection. If enough shielding is be received by a person in a protected location, provided between the individual and the source of compared with the amount he would receive if he were unprotected. Some speak of a material as radiation, such as fresh fallout, the exposure can be having a protection factor of 10, while others ex- reduced to a negligible level. press the same concept with the decimal fraction Protection from the effects of fallout gamma ra- 0.10. Both mean that the intensity of radiation diation may be achieved in two ways—barrier behind the shield is about one-tenth the intensity shielding and geometry shielding. as measured in the open radiation field. In the first method, a barrier is placed between Appendix B relates shelter categories to cor- the fallout field and the individual. The heavier responding protection factors. It is intended to the protective barrier, the greater the barrier provide ( 1 ) a general idea of the relative amounts

RADIATION PROTECTION * from ground contamination

more protection in building with larger ground area when buildings are equal in height

FIGURE 3.—Radiation protection from ground contamination. RADIATION PROTECTIOTT from roof contamination

more protection in building with greater height when buildings ore equal in ground area

FiGUEE 4.—Radiation protection from roof contamination. of protection offered by common types of buildings therefore, not in Immediate contact with man or and (2) a preliminary estimate of potential shelter animals, effectively preventing "beta burns"; areas, the purpose of survey programs. These pro- (2) Radiation is partially absorbed by the roof tection factors may be conservative in many cases, and walls of an ordinary house and by the inter- since they are based on isolated structures. For vening air ; and example, if a building is surrounded by taller (3) Eadiation intensity is diminished through buildings, the protection factor might be increased the effect of distance. For example, experience sufficiently to raise it to a higher protective cate- indicates that a person on the first floor of an ordi- gory. In any case, on-site examination and prac- nary frame house in a fallout area receives about tical judgment must be used in assigning a pro- one-half the gamma radiation dose received out- tection factor to any given structure. of-doors without any protection. If that person If special shelters are not available at the time were in the basement of the frame house, his radi- of a nuclear attack, families should take advantage ation dose would be reduced to about one-tenth of available normal indoor and, preferably, base- the value outside the house. An underground ment-type shelter. shelter covered with a 3-foot layer of earth reduces Normal shelter reduces radiation in several the radiation to less than one-thousandth of the ways: intensity of that on the outside. Cellars, including (1) The source of radiation — the fallout — is tornado and storm cellars, and stone spring houses largely outside, on the roof or on the ground and, also provide substantial protection. Decontamination

Decontamination against radioactive materials tamination where one chemical is used to neutral- is unlike that used against a disease outbreak ize another. Radioactive materials cannot be where a disinfectant, heat, or some other physical destroyed. means is used to destroy the causative organism Therefore, since radioactive materials cannot be of the disease — or in the case of chemical con- destroyed, decontamination involves the transport of the source of radiation (fallout). The fallout Thus, there are two procedures, removal and should be removed from a location where it is a disposal. hazard to a place where it can do little or no harm. Work Schedules in Fallout Areas

Even during an early period following fallout, where feasible, be performed by adults past the farm families will be faced with the necessitj' of reproductive age. doing such farm cliores as caring for livestock and Civil defense emergency exposure criteria indi- making other necessary trips into tlie open. If cate that an acute (short period of time) gamma supplies of food and water have been protected radiation exposure dose of 200 roentgens is not from contamination and are readily available to likely to incapacitate more than a small fraction the shelter, appropriate schedules of work and of the adult population so exposed, and that the time in the shelter can be de^^sed that can save body can gradually repair a large fraction of the lives and reduce injury to men and animals. damage resulting from nonlethal radiation doses. Schedules will depend upon the severity of the Consequently, a person's total radiation exposure fallout radiation hazard and the urgency of the may exceed substantially 200 roentgens without task to be ¡performed. In planning emergency seriously incapacitating him, provided the radia- work schedules the guiding principle should be tion exposure is so distributed over a long period to keep radiation exposures to the lowest prac- of time that the unrepaired portion of the injury tical limit consistent with saving the commu- does not exceed the injury that would result from nity, family, and self. an acute exposure of 200 roentgens. For conven- All but the most important tasks should be post- ience, the estimated unrepaired portion of a per- poned as long as feasible to take full advantage of the decay of the radioactivity. Where possible son's radiation dose is referred to as the Equiva- the radiation exposure should be more or less lent Residual Dose (ERD). evenly divided among the adults available to per- Table 1 presents an example of a work schedule form the necessary tasks. Exposure to radiation for areas contaminated with radioactive fallout. can increase the probability of genetic defects and Of course, where feasible, the periods out of may cause other harmful late effects. For these shelter should be much less, particularly during reasons, tasks involving radiation exposure should. the first few days when dose rates are high.

TABLE 1.—Example of maximum adult wo7'k schedule for «rer«- contaminated hy radioactive fallout {4-ioeek basis) (ERD 100 roentgens; H-l-1 dose rate l,000r/hr—equivalent to about lOOr/hr at H-|-7, or 22r/hr at H-|-24 hours;' shelter factor of 100—1% of unsheltered dose)

Work period Work period Time after explosion (time out of Time after explosion (time out of shelter) ^ shelter per day)

Hour Hours 12 hours (same day or during first 24 4th through 7th day 2 hours). 8th through 14th day 3 2d 24 hours - - _ -. _ _ 1 15th through 21st day 4 3d 24 hours . _.. 1 22d through 28th day 6

' Equivalent dose rates for H-|-7 and H-l-24 hours are stated in order that those possessing "citizens instruments" be able to measure the degree of fallout contamination in their specific areas and adjust the work periods to suit their situations. See text. 2 Work periods may be split—part morning and part evening, for instance. It is assumed that most of the work period on the first day would be spent in a barn or similar structure and that on succeeding days at least one-fifth of the work period would be spent in such structures which provide some protection. First 2 weeks—off-duty hours spent in shelter allowing no more than 1 percent of unsheltered radiation to penetrate. Third and fourth weeks—major portion of the worker's off-duty hours spent in shelter but limited fraction of time could be spent in a typical basement or cellar.

For other degrees of contamination the example the area, all members of the farm family should may be "scaled" to a degree. If the fallout con- remain within their shelter during the first 24 tamination were double that assumed for table 1, hours. Also, if fallout is heavy, say above 1,000 humans might work for half the length of the roentgens per hour at 1 hour after detonation, indicated work periods, provided they had shel- there would be little value in attempting to care for ters with twice the protection. Unless it has been livestock unless they were protected by a shelter determined that there is no radioactive fallout in at least as good as that provided by a basement. In the far more extensive areas where contami- per hour at 1 hour^ltei blast, the uiaAmium work nation is less, scaling of the example presents scheduled could be doubled, if necessary. greater promise. With half the fallout radiation However, the work schedule presented in table 1 intensity (500 roentoens per hour at H + 1 or its is a maximum for radiation exposures approxi- equivalent, 50 roentgens per hour at H+ 7, or 11 mating those that would incapacitate. The schedule also allows considerable time for per- roentgens per hour at H+24) livestock could re- forming most of the important duties. Under main healthy with less shelter protection, although less severe fallout conditions, one would be wise some shelter is still required. Given the same to stay within the time limits shown, if possible, human shelter protection assumed for the area and correspondingly reduce his personal radiation when the radiation intensity was 1,000 roentgens exposure with its associated hazards. Handling Livestock

Livestock owners will generally find it imprac- (1) In the expectation of the immediate possi- tical to remove animals from fallout areas. bility of radioactive fallout, the following should Therefore, facilities for the care of the animals in be observed : shelter and adequate supplies of uncontaminated (a) If sufficient time is available, animals feed and water for at least 2 weeks would be should be brought into shelter. Animals needed. should be kept within shelter at least during If warning of fallout is received, preparations the first critical period of 24 to 48 hours. A should be made for the best possible care of good tight barn would reduce radiation dose animals. by about one-half. The best shelter given Livestock Protection

Fallout

Shielding

Clean Water

Safest Area

FlQUEE 5 -The best protec-tion likely to be available for Uvestock against radioactive fallout is in the basement of tight bam with a loft filled with hay. 10 by a structure normally in use for livestock the dose level that you could expect to kill 50 IS a 2-story basement-type bam with a stor- percent of the animals within 30 days. Poultry age loft filled with hay. Proper use of shel- are more resistant, liaving a midlethal dose of ter for animals can substantially reduce the about 900 roentgens. However, tolerance varies number of deaths and injuries from radiation. among species of animals as well as among animals (b) Milking cows must be given the most within the same species. protected place in the barn, not only for the sake of the animals but also for the safety TABLE 2.—Percentage of mortality of unsheltered of the milkers. The animals' feed should be animals after 2Ji.-hours'' exposure to various reduced to the minimum needed for sub- radiation doses sistence. (c) Provision should be made for a re- serve stock of food in the house and feed in Mortality the barn for the farmer and his family and for the animals for at least 2 weeks. Species 100% 80% 50% 20% (d) If only a limited resem^e of feed is stored so that it will not be contaminated, Exposure dose (roentgens) ' this feed must be reserved for one or only a few milking cows. This milk can then be used by the farmer and his household, pri- Cattle.. 650 600 550 450 300 Sheep-- 700 600 525 450 350 marily for children. Swine. _ 800 700 600 450 350 (e) If time allows, already harvested feed Poultry 1,200 1, 100 900 600 400 lying in the open should be covered with avail- able materials such as tarpaulins. As much ' Exposure dose in area where livectock and building as possible of ready-to-harvest crops should are located. be harvested and protected. (f ) Animals that are not placed in a barn All domestic animals have a similar response to or under a roof might, if possible, be placed total body irradiation. Few if any die after ex- under trees or where they are covered to some posure to 250 roentgens. And few if any survive extent. an acute dose as high as 1,000 roentgens. Smaller (g) It is better to keep animals alive on doses or slower dose rates are tolerated better than contaminated feed and water than to let them faster delivered large doses. Some animals like die from starvation. swine have a much faster recovery rate than (h) Take care to protect as big a water others like the burro, although there is little reserve as possible. In case of radioactive difference in response of the species to acute ex- fallout, it should be remembered that water posure. The body size of the animal has little to from sufficiently covered wells not containing do with survival, although the very young or the surface water must be considered drinkable. very old may be more radiosensitive. During the critical emergency period, in areas contaminated with fallout, the use of Poultry water from lakes, creeks, other surface As indicated in table 2, poultry are among the sources, and collected rainwater should be more radioresistant species of our domesticated restricted. Use the protected water first. animals. Therefore, poultry may represent one (2) It may happen that warning will not of the more dependable sources of fresh foods reach the farmer in time and, therefore, he will not of animal origin which may be available after a be able to handle his animals in the proper man- nuclear attack. Furtliermore, most of the poultry ner as explained in (1). These animals may be raised are reared under shelter or are provided directly exposed to fallout. If practical, they with some shelter available for protection from should be thoroughly washed off as soon as it is the normal environment. Consequently, com- possible for the farmer to stay outside for a pared with other livestock species, poultry should limited time. After being washed, the animals enjoy the greater chance for sunnval following a should be taken into the barn, or other available nuclear attack, because of the greater availability shelter. During the washing, the farmer should of immediate shelter for protection from radio- wear protective clothes, including rubber shoes active fallout. and gloves. The removal of radioactive fallout Still another factor to support the above con- from the hide of the animal is difficult and may be clusion is that most poultry are raised on com- ineffective in some cases. However, it will help mercially prepared or packaged grains or feeds to reduce the radiation exposure of both the animal and, moreover, these feeds are necessarily stored and the animal caretaker or milker. under some form of shelter. Therefore, consider- Acute total body radiation exposures of live- ing the various livestock diets, poultry diets are stock (cattle, sheep, and swine) varying from 500 least likely to be contaminated by radioactive to 600 roentgens provide a midlethal dose—or nuclides. Thus, the hazards of direct and indirect 11 (via the diet) fallout contamination are signifi- feeding with unconttttiiinamd-fg5crsHoïïran>e pr cantly reduced. vided as far as possible. (See Appendixes ü anu C for protection factors and suggested livestocK Shelter shelters.) . . The value of shelter in preventing death and Food animals that have received radiation doses that may result in sickness or death may not show sickness among animals is greatest in areas ex- any injury within a period of 2 to 10 days after posed to acute radiation doses about equal to the average midlethal dose (550 roentgens). At low exposure. Meat from animals exposed to lethal doses of radiation intensities, there is little beneficial effect external radiation may be used for human con- from shelter because no animals would become sumption without great hazard from radiation. sick or die whether sheltered or not. At high The greatest danger to human health in this case intensities of outdoor radiation, all animals would would come from bacterial invasion of the tissues die under either condition. as a result of radiation sickness. This may occur Table 3 indicates the percentage of mortality between the 7th and 12th day after exposure. that might be expected among various species of Briefly, animals can be safely used for food if sheltered and unsheltered animals exposed to dif- they show no temperature rise or apparent injury ferent intensities of radiation. This information or illness. Temperatures may rise from 101.5° to should be considered as a general guide of ex- 108-110° F. when bacterial invasion occurs. Some pected mortality based on current knowledge, and normally edible organs, such as the liver, would not as a forecast of exact mortality rates. The objectives of providing shelter for livestock not be safe. and pouhry are to (1) protect livestock from the If any animal shows signs of sickness, it should lethal effects of radiation, thereby conserving an not be slaughtered for food purposes until it is important food resource and (2) protect the feed fully recovered and in good health. This may and water of food-producing animals from radio- take several weeks or months. Sick animals may active contamination, thereby assisting the produc- be treated according to the symptoms shown. tion of safe food products for human consump- However, if animals have ingested or inhaled tion. After the first critical 24 to 48 hours or when fallout, the butchering process would be compli- outdoor work periods can be scheduled, livestock cated by the additional exposure of the workers to can be given short periods of exercise in areas or fallout on the animal's hides and in the alimentary yards that do not contain contaminated vegetation and respiratory organs. These organs (lungs, or water. ^Yi\en it is no longer practical to keep trachea, stomach, intestines, esophagus, tongue, animals off contaminated pastures, supplemental and lips) must be removed so as to avoid contam-

TABLE 3.—Effect of shelter on the mortcdity rate of livestock ^

Mortality rate by nature of shelter

Kind of livestock and radiation exposure— 2-story barn with Basement-type unsheltered dose (number of roentgens—1 day) Tight wooden loft full of hay barn with loft No shelter barn (protection (protection factor full of hay factor of 2) of 5) (protection factor of 10 or more)

Cattle Percent Percent Percent Percent 500_- 30 0 0 0 1, 000. 100 30 0 0 3, 000. 100 100 80 0 Hogs 500-_ 30 0 0 0 1, 000 100 30 0 0 3,000 100 100 50 0 Sheep 500.. 38 0 0 0 1, 000 100 38 0 0 3,000 100 100 80 0 Poultry 500-_ 10 0 0 0 1,000 64 10 0 0 3,000 100 100 20 0

' The reduction of radiation by shelter is described as the "protection factor." For example, if the protection factor of any given structure is 2, then the intensity of outside radiation is reduced by one-half. See appendix B for additional information on protection factors for other types of farm dwellings. In fallout areas, one-half or more of the radiation would be released after the end of the first day.

12 inating usable parts. In this case, only muscle hides, organs, and other parts containing fallout and muscle fat would be safe for use as food. The must be disposed of by burial. Irradiation Effects on Animals General Sexual and Genetic Effects In general, domestic animals are about as radio- Sperm or ova production is halted following sensitive as man. There is no specific therapy for total body irradiation in the lethal dose range of radiation sickness. In presumed cases of serious 300 to 800 roentgens, and is not resumed until radiation in]\uy, animals should be placed under several weeks after general recovery. Male ani- observation and treated symptomatically if signs mals irradiated within the lethal range, however, of radiation sickness appear. Animals surviving maintain some interest in females in estrus up to the first few weeks following a brief exposure may just a few days before death. These animals may be expected to recover. be fertile, as spenn may survive in the testes for Limited studies indicate that unsheltered ani- a number of days after exposure to radiation. mals that fail to develop beta burns after having Doses in the lethal range are necessary to produce been in the path of a fallout cloud will ordinarily sterility. escape serious external radiation injury. Animals that sustain exposure intense enough to produce Embryologie Effects beta burns but live longer than 3 weeks or a month should recover. Irradiation of the embryo is particularly haz- If areas have been subjected to sublethal ardous. Doses ordinarily without danger to the amounts of fallout, animals may develop signs of female can be of grave consequences to the embryo radiation sickness. Such animals might be placed during early pregnancy. The abnormalities en- on clean, uncontaminated feed and treated symp- countered are associated almost entirely with tomatically. Treatment may include the use of cessation of development of growth of a particu- antibiotics until they either recover or die from ex- lar organ or organ system brought about by posure to radiation. irradiation. PROTECTION AGAINST INTERNAL RADIATION FROM FALLOUT

The second phase of radiation hazard from fall- larly for children. As time passes and the ini- out is internal radiation ; that is, exposure to the tially contaminated food and feed have been radiation from isotopes that enter the bodies of discarded, the principal source of internal radia- animals and human beings. These radioactive tion for man and animals is indirect — from the elements generally enter in food and water. radioisotopes in the soil which are absorbed At first, the principal source of internal radia- through plant roots into food and feed crops. tion is external contamination of edible plants "V-N^ien meat and dairy animals eat contaminated when fresh fallout drops on the affected area. feed, some radioactive elements are absorbed into For livestock, this would include primarily forage their bodies. Thus, man's food supply of both grasses and legumes. For man, it would include plant and animal products can become contami- fruits, vegetables, and milk — the last particu- nated with radioactivity. Radioisotopes Causing Internal Radiation

Many of the radioactive isotopes created by nu- most significance as internal radiation hazards are clear explosions are of minor concern, in the haz- barium 140, iodine 131, iodine 133, cesium 137, ard of internal radiation, because of (1) the small strontium 89, and strontium 90. amounts involved; (2) their extremely short or Radioactive iodine, because of its chemical extremely long half-lives; or (3) the fact that identity to ordinary iodine, accumulates in the thy- they are not incorporated into the food chain (see roid gland when it gets into man or animals. glossary) and hence do not seriously affect man However, iodine 131 has a relatively short half- and animals. life of 8 days. Iodine 131 will not be an impor- Among the isotopes that are taken up m the tant long-term fallout hazard, but it is the most food chain are the following : Barium 140, cerium hazardous internal emitter during the first 60 144, cesium 137, iodine 131, iodine 133, promethi- days. When considering the dosage to the thy- um 147, ruthenium 106, strontium 89, and stron- roid derived from radioiodine in the first few tium 90. Of these, the radioactive isotopes of days after attack, it is important to consider both

644700 0—62- 13 MOVEMENT OF STRONTIUM 90 On and Into Plants

r 90 absorbed by leaves and soil

•••••••

FIGURE 6.—When fallout first arrives, It falls on the surface of the plant and soil. As time passes strontium 90 is absorbed into the plant leaves and into soil where it is available to be taken up by the plant roots along with nutrients.

iodine 133 and iodine 131. Iodine 133 has a half- probably can produce serious consequences, such life of 22 hours but occui's in sufficient quantity as bone cancer. Children are relatively sensitive to make a significant contribution to the thyroid to radiostrontium, because during their early radiation dosage. growth period they require larger quantities of Cesium 137 has a long half-life of 27 years and calcium than adults, a greater fraction of the in- is chemically similar to the essential nutrient ele- gested strontium is deposited in their bones, the ment potassium. When cesium 137 is consumed concentration of strontium is more uniform and absorbed, it is found primarily in muscle throughout their skeletons, and because they have tissue and can cause several types of cell damage, longer life expectancies for a slowly developing including genetic damage. But this radioisotope disease such as bone cancer to occur. is not retained long in the body. It continually Barium 14-0 behaves similarly to strontium 89 enters and leaves the system just as does and strontiimi 90 in that it is deposited in the bone. potassium. However, both the proportion of ingested barium Strontium 90, however, with a half-life of 28 140 that reaches the skeleton and the half-life years, is of primary importance, Strontium 89 is chemically identical, but it has a half-life of (12.8 days) are smaller than for radiostrontium, only 53 days. They behave much like calcium in so that barium 140 contributes less to the bone soils, plants, and animals. Nuclear explosions hazard. produce large amounts of radioactive strontium. Although the radionuclides mentioned above It is taken up in biological systems, in plants, is are of special concern in view of their predomi- secreted in milk, and collects in bones, where some nance in the food chain, total fission products in of the strontium !)0 remains for years. Radio- fallout have to be considered in the event of food active isotopes of strontium deposited in the bone being contaminated directly with fallout. While 14 only the group described above passes into the it passes through and can cause serious injury. blood stream in significant quantities, the entire The results of tliis damage are among those that material irradiates the gastrointestinal tract as appear earliest. Protection of Food, Feed, and Water

The concern in protecting food, feed, and water Fallout particles that fall directly on food and is to prevent the consumption of contaminated forage plants contaminate them by remaining at- materials that would subject man and animals to taclied to the aboveground parts, or by releasing internal radiation hazards. However, the imme- radioisotopes that are absorbed into the leaves and diate problem is to protect a sufficient quantity other plant parts. Rain and wind move tliese from fresli fallout to provide for survival during particles from plants to soil, but certain charac- the critical period. teristics of the leaves, such as hairiness and rough- The principle of protecting food, feed, and ness, increase the retention while smoothness re- water from external fallout is simple: Prevent duces it. the fallout from becoming mixed or incorporated Strontium 89, strontium 90, and ruthenium 106 into these materials. They may be irradiated by absorbed into leaves tend to remain there because the fallout, but if the radioactive particles do not they do not move readily into the other parts of come in actual contact with them — or if the the plant from the leaves. On the other hand, fallout is removed — tliey will not be radioactive cesium 137 and iodine 131 will move readily and tlius will be safe to eat or drink. Methods throughout the plant from the leaf. Accordingly, of prevention would be the same as those for pre- internal contamination by strontium 89, strontium venting dust from contaminating food or water 90, and ruthenium 106 from leaf absorption is if tlie air were lieavily dust-laden. Fallout can greatest in leaves and is comparatively less in also be removed in much the same way as dust — fruits, seeds, and edible roots and tubers. As the by washing, vacuum cleaning, and brushing. Pre- season progresses, the fallout contaminants that cautions should be taken to avoid inlialing or in- have accumulated in the leaves, especially stron- gesting the material while removing it. tium 89, strontium 90, and ruthenium 106, may be washed from the leaves to the soil in rain and Food dew. They may then be absorbed by the roots and Radioactive fallout deposited on agricultural distributed throughout the entire plant and land will contaminate food chains with radioiso- thereby increase the total content of contaminants. topes by way of the soil and crops. It may, de- In arid regions with little rainfall these contami- pending upon the radiation intensity level, pre- nants are not washed to the soil from the leaves, vent farmworkers from handling crops properly. and any new growth that develops after the fall- The deliberate overexposure of farmworkers to out will be relatively lower in strontium 89, stron- radiation in order to save contaminated crops that tium 90, and ruthenium 106. are not essential or might be discarded later is Vegetables and fruits harvested from fallout not warranted. Depending upon the stage of zones in the first month after attack will require growtli when fallout occurs, salvage of unhar- decontamination before they can be used for food. vested crops such as grain, fruits, and vegetables First, the exposed parts must be thoroughly would be impaired By crop contamination, ex- washed to remove the fallout particles. Then ternal exposure hazard, and unavailability of fuel vegetables or fruits should be peeled, pared, or and machinery. the outside otherwise removed in such a way that For example, if fallout is heavy, ripe fruits hands or utensils do not contaminate the parts to may be lost because of the personal hazard in be eaten. It should be possible to decontaminate harvesting them. Fruits that do not have to be almost completely such crops as apples, head let- picked immediately and that can be decontami- tuce, and cabbage by repeated parings, washing nated by washing and peeling before eating can hands, and washing utensils before each paring. probably be saved. Orchard trees should be main- Since fresh fallout provides only surface contami- tained as usual and the fruits monitored for nation, it should be possible to wash and shell peas and beans or husk sweet corn to remove the con- radioactivity. taminated parts. This type of decontamination Consequently, the land contamination problem could be applied to many human food items in the in heavy fallout zones would be primarily a long- home immediately after harvest, preferably using term soil contamination problem. For most crops well water, or other noncontaminated water. and soils, about 1 percent of the available stron- Cooking will not destroy radioactivity. tium 90 in the soil is removed in a single crop. Some food products that have fallout on or On sandy soils, some crops may remove as much mixed in them can be used only after holding l;he as 5 percent. Even at this higher rate of re- products long enough to allow the radioactivity moval, more than 40 crops would be required to to decay to a safe level. Storage of the contam- achieve 90-percent decontamination of the soil. inated material for a period ranging from 2 weeks 15 to several months, depending upon the degree of exclude dust will Ije-ÊAectiro^—Reírigeraííon fa- contamination, will reduce the amount of radio- cilities should be maintained as usual to control activity present, usually to a negligible level. This spoilage. is due to the comparatively fast rate of radioac- tive decay. Obviously, many food products, in- Feed and Water cluding most meat that is not canned, could not Because early radioactive fallout is dustlike in be stored for the necessary time. Fallout on un- character and results in surface contamination, paekaged meat presents a salvage pi-oblem, since it the simplest method to protect feed and water is is extremely difficult to remove the outer surface to place a cover over them to prevent fallout from without carrying contamination onto other parts coming in direct contact with the materials. of the meat. Washing is not an effective method Grain stored in a permanent bin and ensilage in of removing this type of contamination. Meat a covered silo are provided with adequate protec- products contaminated with fresh fallout could tion against fallout, and the contents can be safely be canned and then stored until the radioactivity used as soon as the farmer is able to get into the had decayed sufficiently. Meat and meat food products in home or com- area to use them. The haystack in an open field mercial storage will be most effectively protected can be protected with a covering such as a tar- if canned. For uncanned products, a sealed cover- paulin. The fallout will lodge on the tarpaulin, ing of one of the commonly available plastic films, but by carefully removing it, the radioactive fall- such as polyethylene, will provide adequate pro- out will be removed. The hay and the contents of tection from contamination by fallout. Even the feed bin and silo would not be radioactive and fiberboard and similar tight containers that will could be used immediately as safe feed for live- Protection - Feed and Water

Well or Spring

^''TitlTht ^¡Felfl\^ Z\uT^:L7'' ^'^"' 'T^'^'K'''' ''''' "^^^ "''^t^'- P-^^^^^t fallo'^t f'-o«^ becoming mixed far:¿ rTmra'fr^m^Lt^ov^erAVeTeïa^ ^-^ «>- ^-<^^-ed, w.en t.e 16 stock. Many materials such as uncovered hay- in the water and its adsorption by clay on the stacks and piles of farm produce may be safely sides and bottoms of the pond or lake will be ef- used as food and feed if the contaminated outer fective in reducing the liazard below that of the portions are removed. surrounding land. The mere boiling of water con- Water stored outside—such as in stock water taminated with radioactive particles will not make troughs—should be covered with any material that it safe but distillation does remove nearly all of would normally keep out dust. Larger farm ponds the radioactive material. and lakes would be difficult if not impossible to Water from covered sources, such as springs and protect. As time passes the problem of contam- wells, would be essentially free from contamina- ination of ponds and lakes may not be a major tion even in heavy fallout areas and could be used problem. The dilution of the radioactive fallout for man and animals with confidence. Radioactive Iodine and Radioactive Strontium in Food

The study of radioactivity in milk has been more TABLE 4.—A general guide to the periods of time Avidespread than in other foods for several reasons. before contaminated milk should be consumed ' Milk provides a vital part of the Nation's diet, particularly for young children, invalids, and Time before consumption by— older people for whom substitutions in diet are Roentgens per hour difficult. Because of the normal system of pro- atH-t-l duction and distribution of milk in this country, Infants Children Adults it is one of the easiest foods to obtain for testing at under 2 2-16 over 16 central points and, therefore, more testing of milk years years years has been done. Milk is produced throughout the year in all sections of the country so that samples Weeks Weeks Weeks 10 0 0 0 are always available. 30 1 0 0 Several radioisotopes ingested by dairy animals 100 3 1 0 can be secreted in milk to an appreciable degree. 300 5 3 0 Among them are iodine 131, strontium 89, stron- tium 90, barium 140, and cesium 137. The most 1 Estimates based on radioiodine contamination and the important of them are usually considered to be io- rate of its radioactive decay. To be used only if adequate dme 131, strontium 89, and strontium 90. The ef- alternative sources of milli are available and if specific fects of others are believed to be less important. local information is lacking. Radioactive Iodine fore, a greater amount of radioiodine is required to damage the adult's than the infant's or child's For a period of days following a heavy deposi- thyroid. tion of fresh fallout, iodine 131 may be a major Table 4 is a suggested guide that would result radioactive contaminant of vegetation, including in a milk contributing not over 200 rads to the food crops such as fresh vegetables and fruits. child's thyroid or 1,000 rads to that of the adult. After ingestion by animals, iodine is rapidly ab- Table 4 is intended as an approximate temporary sorbed from the gastrointestinal tract, collected guide to the usability of fresh milk during the in the thyroid gland, and secreted in milk and fii'st part of the critical postattack emergency eggs. period. If alternative uncontaminated sources of In the event of a nuclear attack, radioiodme milk in various forms are unavailable or inade- would be the most critical single factor in the con- quate for subsistence, the guide should be ignored tamination of milk during the first few weeks to the extent necessary for the maintenance of life after an explosion. The hazard would decrease and general health. As alternative assessment of relatively rapidly (see table 4) because of radio- the food situation and analytical measurements active decay, but the short-time problem would be on milk become available with the passage of time, serious in some areas. the general guide should be supplanted by specific A large fraction of the radioiodine ingested by knowledge of a local situation. human beings, ranging from about 20 percent for Since milk is an essential food for infants and adults to 50 percent for children, is deposited in other young children, and the weight of milk con- the thyroid gland. In addition, children are rela- sumed by them is high in relation to their body tively more sensitive to radiation of the thyroid weights, the contamination of milk witli radio- than are adults. It has been estimated that the iodine during the first weeks after nuclear attack ingestion of 5 microcuries (see glossary) of radio- would be primarily a problem of thyroid injury iodine would result in a dose of 200 rads (see glos- to young children. sary) to the infant's thyroid. The infant thyroid Studies indicate that sheep whose thyroids have weighs about 1.5 grams, whereas the adult thyroid been exposed to radiation doses ranging from weighs about 20 grams. For several reasons, there- 50,000 to 70,000 rads do exhibit serious patho-

17 logical and physiological disfunctioning. Ob- Confining dairy^fcnimals to reasonable dust- servations on cattle show that they require at tight buildings and providing them with clean, least twice the radiation dose of sheep for thyroid noncontaniinated feed and water will aid greatly changes. in minimizing the contamination of the dairy The hazard discussed here is created by dairy products produced. animals orazing on vegetation contaminated witli If, despite all precautions, fluid milk supplies radioiodine from fallout and thus producing con- should become contaminated, a number of steps taminated milk. Available information indicates could be taken to avoid danger to consumers. that from 5 to 10 percent of tlie daily intake of Since the half-life of iodine 131 is only 8 days, its iodine 131 is secreted in milk of dairy cows. On decay is moderately rapid and delayed mai-keting the basis of current knowledge, suggestions have is a key to safe usage of contaminated milk and been developed for reducing the hazards of radio- dairy products. iodine in milk in the event of a nuclear attack. If the contamination of milk supplies with Milk produced from pastures that received iodine 131 were fairly localized, milk from other fallout equivalent to a radiation level of 30 areas with little or no contamination could be di- roentgens per hour or higher 1 hour after a verted to contaminated areas for immediate con- nuclear bomb explosion should not be used im- sumption, and the contaminated milk processed mediately for consumption by infants. For ex- and stored for later consumption. If contamina- ample, several days after a nuclear explosion, civil tion were widespread, this might be impractical defense authorities measure the radiation level in and consumption of fresh fluid milk would have a given area. F'rom this measurement, the equiva- to be deferred until radioactivity was reduced to lent radiation level at H + 1 can be calculated. If safe levels. this is as high as 30 roentgens per hour, then milk For high rates of contamination, storage for 1 to produced by cows grazing in that area should not 2 months might be necessary before iodine 131 be used as fluid milk by infants for 2 weeks after was reduced to safe levels. Freezing of packaged the explosion, unless speciñc radioiodine measure- milk in paper cartons for storage before delivery ments show the milk to be safe or other sources would be one way of handling the problem. The of usable milk are lacking. Table 4 indicates the frozen product would be thawed before delivery to time before acceptance at other levels of radiation. the consumer and the consumer would have no It would be best to have a means of expediti- responsibility for keeping track of storage time. ously determining the iodine content of milk; for During the period when fresh milk supplies were example, a special monitoring instrument (milk not available, reconstituted dry milk or canned counter probe for radioiodine). Until such equip- milk could be safely used. ment is developed and available, table i can be Any of these marketing modifications would be used as a guide. difficult. Nevertheless, they could become neces- Stockpiles of storable milk or milk products sary. for children are needed. Some areas, aiïected by There should be no destruction or disposal of fallout but not by the bomb blast, may not be milk contaminated with iodine 131, since it can producing safe fresh milk for 2 months if the be processed into products such as butter, cheese, above standards are met. Therefore, families with powdered milk, and canned milk, and stored for children should keep an ample supply of powdered a period of time to allow the decay to take place. milk, whole or skim, or canned milk on hand to If processing facilities are not available locally help provide necessary nutrients during this pe- or are not adequate to handle all the milk involved, riod. This supply should be rotated into current the contaminated milk can be fed to pigs or calves. use and the reserve replenished regularly. Infants and persons with special dietary needs should get safe milk supplies where lim- Reducing Iodine 131 Contamination of ited. During the first weeks after the explosion, Food and Dairy Products adults and children who can get an adequate diet On the premise that radioactivity from iodine from other foods should leave the restricted safe 131 has largely disappeared from materialt^ after milk supply for infants and others for whom it is a 2 months' period, the dairy farmer can confine a mainstay in the diet. Mothers should breast- lactating animals to the barn before the appear- feed their babies during this period insofar as is ance of fallout in the area and provide forage and consistent with medical advice. feed that had been harvested before the detonation Milk produced from existing vegetation in or stored for 2 months after exposure to fallout. areas of higher radiation levels can be con- Freshly contaminated forage can be fed to non- verted into storable dairy products or animal lactating stock. Concentrated mixtures prepared feed. In areas for which the relevant radiation on the fann should be prepared from grains har- level at H + 1 was from 30 to 300 roentgens per vested before the fallout or that have been stored hour, dairy cattle may have to continue to graze for 2 months or longer. Ensilage that has been contaminated pastures. The milk production can stored for at least 2 months could also be a safe be converted into such products as dried milk, feed for dairy animals. canned milk, cheese, butter, and ice cream. These 18 products should be stored until the radioiodine has remaining soil. Small areas at the base of slopes decayed to a safe level as indicated by table 4. may accumulât« this material. Areas subject to The milk might also be fed to calves or pigs, and accumulation should be monitored frequently, the meat thus produced would be safe for human especially if used for food crops. consumption. Radioactive Strontium in Food Radioactive Strontium Strontium is similar to calcium in behavior and After the first 60 days, the principal hazard of is closely associated with it in soil and food and radioactive contamination in milk arises from bones. Strontium in the soil is taken up by plants strontium 89 and strontium 90. The strontium 89, along with calcium. however, will have virtually disappeared by 1 year Fortunately, the metabolic processes of both after its fonnation. Just as other radioactive animals and humans act to reduce substantially isotopes of fallout, strontium 90 falls on the sur- the amount of strontium that is deposited in the face of plants and can be consumed with foods bones of man relative to that of calcium, as com- and forage. Some of it is deposited directly on pared to the amount that was originally present the soil or washed into it, remaining indefinite- in the vegetation and in the soil on which it grew. ly — for all practical purposes — in the top sev- This protective mechanism is measured by the term eral inches. "discrimination factor" and refers to the natural The return to earth of strontium 90 in world- preference that the body has for calcium over wide fallout from large nuclear detonations is strontium. Relatively more calcium than stron- rather slow. Raijifall is the principal mechanism tium is carried along as these elements move to- that brings stratospheric strontium 90 to the gether through the food chain from the soil to the ground from the air. plant and then through the body to the bone. In Strontiimi 90 movement into plants has an im- milk the discrimination process operates twice. portant association with plant physiology and soil The biological system of the cow screens out over conditions. There are two general routes of 90 percent of the strontium in her diet, and the entrance for strontium 90 into plants. The first biological system of man screens out still more is direct contact with the parts of the plant oc- of the strontium consumed in milk. The same is curring above the soil. As time passes, following true, but to a lesser extent, in the production of the deposition of fallout, the second route •— en- meat and eggs. trance into the plant roots through the soil — be- About 70 to 80 percent of the calcium in the comes relatively more significant. average diet in this country comes from milk and Strontium 90 enters plants by three means cheese. But calcium from these sources carries other than from the soil through the root system. only about -iO percent of the soil-derived strontium These avenues are floral, foliar, and stem base or associated with our food. root mat. Meat and eggs contribute only about .5 percent The floral route is fairly common in plants. of the calcium and 5 percent of the soil-derived Cereal grains are good examples. Rain bearing strontium in the diet. Plant foods — grains, strontium 90 collects in the upturned flower of vegetables, and fruits — furnish about 15 percent the plant. At least a part of this contamination of the calcium in the diet but, because they are is retained by the developing kernels. consumed directly, they would furnish about 55 Strontium 90 may also gain entrance into the percent of the total soil-derived strontium. plant by foliar absorption, that is, through the Because of the discrimination factor within the leaves. There is, however, little movement of human body, the ratio of strontium to calcium re- strontium 90 from the leaf to other parts of the tained in the bone is only about one-fourth to plant. Consequently, the oldest leaves of a con- one-half (the latter value is especially applicable tinuously exposed plant have the heaviest internal to children) as great as the ratio of these two ele- concentration. With cabbage or head lettuce, re- ments in the diet. For example, if the ratio in moval of the older outer leaves removes most of the human diet is 16 micromicrocuries of stron- the contamination from this source. Grazing tium 90 to 1 gi-am of calcium, then the ratio in animals, however, usually consume these parts of the bone will be about 4 micromicrocuries of stron- grass if the pasture is used at its optimal capacity. tium 90 per gram of calcium. Another route for the entrance of strontium 90 Milk should continue to be the outstanding into a plant occurs in permanent pastures com- source of calcium in the diet, because the calcium posed of perennial grasses having a root mat, by it supplies has had much of the strontium present absorption into living roots and stem bases in the in the vegetation screened out by the biological mat. system of the cow. As a rough approximation for sloping land, It should be remembered that milk is an essen- about 90 percent of the strontium 90 that falls on tial source of calcium for the bones and teeth of the soil will remain where it falls. Studies indi- growing infants and children. Any widespread cate that soil material eroded by surface runoff disruption of the production and distribution of is about 10 times as high in strontium 90 as the this nutritionally essential commodity could create 19 SOURCES OF CALCIUM AND STRONTttJMTO From Food

CALCIUM STRONTIUM 90

^ MILK ^ PLANTS myj MEAT

FIGURE 8.—Sources of the calcium and strontium 90 that are contained in human bones are principally milk, plants, and meat. The discrimination factor is demonstrated by the large percentage of calcium derived from milk while the relatively small amount of strontium 90 is being accumulated. individual and public health hazards far more im- simply adding mineral calcium to an otherwise mediate and serious than might be created by the adequate diet. First, any dietary modification amounts of radioactive exposure involved at low would have to be carried out continuously over a levels of strontium 90 contamination. reasonably long time period to permit adaptation Additionally, reduction of milk consumption of the animal. Secondly, it would be difficult to by children, without competent medical supervi- get a dairy cow to eat more than 200 to 300 grams sion, could not only result in nutritional imbalance of calcium per day and higher levels might be in- but might actually increase strontium 90 exposure, advisable from the standpoint of the health of since milk has a lower strontium-to-calcium ratio the animal. Thus, if animals were normally con- than other foods. suming about 80 grams of calcium per day, a re- Also, results of research on animals indicate that duction factor of 2 to 3 is the most that could be a body well nourished with respect to calcium does expected by increasing the calcium intake on a not retain so much strontium as a body that is usual diet. deficient in calcium. A ration consisting of 8 pounds of alfalfa hay, In a contaminated environment, rations for 12 pounds of timothy hay, and 12 pounds of grain dairy cattle can influence the strontium 90 content would supply a dairy cow with about 80 grams of milk. For example, a diet of grass hay, corn, of calcium ; mineral supplementation to 160 grams and inorganic calcium would provide less stronti- daily would be expected to give a reduction factor um for the animal than a diet of legumes, such of about 2. On the other hand, a ration of 20 as clover, lespedeza, or alfalfa, which are good pounds of timothy hay and 12 pounds of grain sources of calcium but which Avould also contribute would supply about 40 grams of calcium per day, a greater amount of strontium. and supplementation to 160 grams would provide Eesearch studies clearly show that the level of a reduction factor of about 4. The two reduction strontium 90 contamination of milk will depend factors are comparable only if the total strontium upon the amounts of strontium 90 and calcium in 90 is equal in both rations. the ration. There would seem to be little gain in In the event that it is necessary to shift from 20 legume hays to the feeding of grass hays to dairy Energy Commission is resulting in the develop- cattle and to supplement their calcium intake, it ment of a procedure for removing radiostrontium is recommended that the gi'ass hays be liberally from milk. The procedure is similar to that used fertilized \YÍth nitrogen fertilizer in order to get in many homes to take the hardness out of water acceptable yields and that the hays be harvested at and to that used in some dairy plants for many the stage when they will be most palatable and years to prepare low-sodium milk. digestible and contain the greatest yield of usable This procedure will provide a means for remov- nutrients per acre. ing strontium 90 from milk that can be placed in To help assui'e the availability of a safe milk the dairy plant on a standby basis to be available supply following a nuclear disaster, cooperative in case of an emergency. research between the U.S. Department of Agricul- Studies indicate that the procedure can remove ture (Agricultural Research Service), the U.S. up to 90 percent of the strontium 90 in milk, and Department of Health, Education, and "Welfare that neither the mineral content nor the flavor is (Public Health Service), and the U.S. Atomic appreciably altered. Croplands Contaminated by Fallout

A nuclear attack on this country could contami- because succeeding crops grown on this soil would nate huge areas of crop and rangelands with radio- take up some of the contamination. active fallout. This contamination presents a The first hazard, external exposure, can be at twofold problem: (1) the external exposure of least partially combatted by observing maximum agricultural workers who attempt to enter heavily work periods and denial times for outdoor activity contaminated areas — or to leave protective shelter as suggested in table 1. In combatting the second in such areas — to carry out farm duties ; and (2) hazard, research workers are conducting studies the. continued production of food without exces- on methods of using contaminated soil for agricul- sive internal radiation hazard to the population. tural purposes or for decontaminating it. Use of Contaminated Land

One of the first decisions to be made by agricul- TABLE 5.—Guide for land usage, hosed on soil tural leaders is how to use land contaminated contamination levels of acid-soluile strontium, with fallout in order to continue to produce, in- 90 above which production of foods should he definitely, a diet that permits the survival of the limited, hy available calcium level of the soil'^ people without exposing them to unacceptable in- ternal radiation hazards. Table 5 has been devised Contamination level per to serve as a guide for such decisions. Land con- square mile on soil with— tamination levels ( acid-soluble strontium 90 is as- sumed to be the long-term available strontium 90) Product of land Low Ca Medium High Ca for each food group are based on the expected (2,000 Ca (20,000 strontium 90 content of the foods. Land contami- lbs. /A.) (6,000 Ibs./A.) nation levels for denial of the use of the land for Ibs./A.) the various food groups may be raised or lowered as more information becomes available. Under Curies Curies Curies no circumstances should land be cultivated if the All foods in the diet, if they farmer or rancher thereby will expose himself to all come from a contami- nated area 3 10 30 unacceptable levels of external radiation. All foods other than dairy With the present average diet, Americans are products, if they come from presumed to derive about two-fifths of their stron- a contaminated area, and dairy products are free tium 90 from dairy products, one-twentieth from from contamination 5 15 50 meat and eggs, and the remainder from plant Meat, eggs, and poultry, if foods, including fruits, vegetables, and cereal all other foods are free products. If uncontaminated milk and dairy from contamination 60 200 600 products are used, other foods from plant and ani- mal sources can be accepted from land with 50 ■ This guide is based on a daily intake of 2,000 micromi- percent more contamination (as indicated m table crocuries of strontium 90. 5) without exceeding the recommended limit for strontium 90 in the total diet. If dairy products The amount of contamination of crops with and food from plant sources could be obtained strontium 90 depends markedly on the available free of contamination, meat, eggs, and poultry calcium content of the soil. For simplification of could be accepted from land with much higher the table, soils have been grouped as being low, levels of contamination. medium, or high in calcium content of the root 21 zone, which is considered to be about 1 foot for ample, r1t>r^r.r.fgr^r^.^fi^p »-f tlin oni^—hv SUCh most soils and crops. A sandy loam soil of pH methods as surface soil removal and deep plowing about 5 may contain 2,000 pounds or less of avail- would increase the suitability of the land for agri- able calcium per acre. An average loam soil of cultural production. pH about 6 may contain 6,000 pounds of available Contaminated land may be diverted to other calcium jjer acre and \yould be considered medium. uses if the radiation level is too high for the origi- A silt loam or silty clay loam of pH about 7 may nal type of production. The diversion may mean contain 20,000 pounds or more of available cal- changing the species of crop grown on the land. cium per acre and would be considered high. The The quantity of strontium 90 absorbed could be available calcium contents of most agricultural reduced by growing crops with low concentrations soils of the country are well known from soil test of strontium and calcium in their edible tissues. data. (See map of the exchangeable calcium con- Potatoes, which contain about 10 milligrams of tent of U.S. soil.) calcium per 100 calories, are a particularly suit- A delay of several months or longer might able crop in contrast to leafy vegetables, which elapse before strontium 90 analyses could be made may contain from 100 to 1,000 milligrams of cal- on many contaminated soils. Therefore, it is rec- cium per 100 calories. Corn would be another low- ommended that temporary land use be based calcium crop to consider. Sugar and oil crops on the standardized gamma radiation intensity would also be suitable low-calcium crops for sub- at H + 1. On low-, medium-, and high-calcium stitution on land too heavily contaminated to pro- soils, the recommended intensities, above which duce other foods. In general, crops producing crop production should be limited, are 100, 300, high-calcium foods should be grown on the less and 1,000 roentgens per hour, respectively. The contaminated land. However, since plants are a purpose of the temporary limitations is to mini- source of calcium, the calcium content of diets con- mize in a practical manner the cultivation of land taining only low-calcium crops would be low. that should be decontaminated before plowing. Unless alternative sources of dietary calcium were The denial of land use, on the basis of stron- provided, a change to low-calcium crops would tium 90 analyses, is suggested for an indeñnite pe- have obvious limitations. riod unless modified by other measures. For ex- Land formerly used for dairying can be diverted EXCHANGEABLE CALCIUM CONTENT ^^4.^ OFU.S. SOIL ^^^^ÊÊÊÊ^UgÊmÊm^^^^^gff^-^y^.-yA ' ^^^^

\i . vl vB ^ ^^^■raS^^^S^^^

CALCIUM CONTENT MiiliequivalenI Thousond lb, per lOOg of soil per ocfe foot Low Less than 5 Less than 4 p ^^^^A Medium 5-15 4-!2 ,]^i' MARCH I960 ^^B M High Over 15 Over 12

22 to the production of beef or other meat. The For most soils and crops, it is recommended that strontium retained by animals grazing contami- lime not be applied in excess of the amount of nated pastures or eating contaminated hay goes calcium needed for maxinmm crop growth. mostly into the bones or milk and not into the In the production of small cereal grains, the meat. Consequently, the meat produced on con- addition of more calcium than is needed for op- taminated land, within the limits set in table 5, timal growth may be helpful in reducing the could be boned and used for food. strontium hazard, without reducing the quality or Byproducts of crops produced on contaminated quantity of the crop. land, such as beet pulp, and cottonseed, linseed, The application of lime to the surfaces of estab- and soybean oil meals, should be used as animal lished pastures increases the calcium content of feeds only in accordance with the levels of con- the vegetation. An application rate of 2 tons of tamination set in table 5. Milk produced on con- lime per acre, for example, has lowered the ratio taminated pastures could be used as feed for meat of strontium to calcium in grass pastures by production. two-thirds. Another divereion might be to take the land out Farmers should use the amount of lime recom- of food production and use it for the production mended by their county agents or State officials to of cotton fiber, flax, castorbeans, timber, or other bring the soil approximately to pH 6.5. The nonedible commodities. If the land is very heavily limestone should b© finely ground so that it will contaminated, it might have to be taken out of react quickly with the soil. On plowed land, it agricultural production for an indefinite period should be mixed thoroughly and as deeply into or decontaminated. the soil as possible. A surface application on pastures growing in acid soil will also reduce the Reducing Strontium 90 Uptake With strontium 90 content of forage, but it may not be Soil Amendments possible to use as much lime on pastures as in The addition of lime, gypsum, fertilizers, or plowed soil. organic matter in practical amounts usually re- Best results from liming are possible on infer- duces the uptake of strontium 90 by less than 50 tile or highly acid soils of the type found in the humid eastern half of the United States. This percent. Combinations of soil amendments and is because acid soils are low in available calcium, tillage practices may reduce the uptake more than and lime, a calcium compound, makes this essen- would any single amendment. The best use of soil tial nutrient available to plants. In low-calcium amendments for maximum crop production is soils, the plant's need for the calcium leads to often the same as their best use for reducing stron- absorption of the similar element, strontium. tium 90 uptake. Thus, liming would have no appreciable effect on The plant's need for the calcium of lime or gj'p- strontium intake in good agricultural soils con- sum leads to the absorption of the chemically taining plenty of available calcium. similar element strontium. In soils low in ex- No one season is best for applying lime but, in changeable calcium, more strontium 90 will be areas where the winter weather is cold enough to taken up by the plant. By liming acid soils, more harden the ground, f.^rmers often prefer to apply calcium is made available to the plant and less lime when the ground will support heavy spreader strontium 90 will be absorbed. It is useful on equipment easily. highly acid soils on which liming would be nor- Potassium fertilization of soils of relatively low mally beneficial for other reasons. Gypsum would available potassium content at the rate of several be most useful on soils containing large quantities hundred pounds per acre can also reduce the up- of exchangeable sodium, which would normally take of strontium 90. However, the calcium up- need gypsum regardless of the strontium 90 haz- take by the plants is also reduced by this practice. ard. However, usually at best, the application Crop residues and manure applied at the rate of of lime can reduce the strontium uptake to only 20 tons per acre have reduced the uptake of stron- about one-half of that from untreated soil. tium 90 by one-third. Croplands Contaminated by Irrigation Water

Irrigation waters will not add much stron- ditch banks. Any strontium remaining in the tium 90 to agricultural land compared with direct water is subject to adsorption at the surface of fallout on the cultivated soil or on crops them- the cultivated soil with which the water first comes selves. Strontium 90 and other fallout isotopes into contact, and thereby is added to the surface are considerably diluted in surface waters of any accumulation originating from direct fallout. appreciable depth. Most of the radioactive con- taminants, including strontium 90, are readily Direct contamination of crops by sprinkler irri- adsorbed by the soil of the banks and bottoms of gation with contaminated water pumped from lakes and streams. They are subsequently ad- lakes, streams, or ponds would be a greater haz- sorbed further by irrigation canal linings and ard, particularly from the contamination of leafy 23 EFFECT OF LIMING ACID SOIL On Uptake of Strontium 90

M<.' :

FiGTJEE 9.—Addition of lime to contaminated acid soil dilutes the strontium 90 present and favors the uptake of calcium instead of strontium 90 by plants.

vegetables. Irrigation water used for such crops, in radioactive contamination as acceptable drink- applied with a sprinkler system, should be as low ing water. Reclaiming Contaminated Land Agricultural land should not be subjected to smaller remedial factors at various successive links drastic remedial measures such as decontamina- in the food chain. tion until after it has been seriously contaminated Decisions concerning the application of drastic with strontium 90. measures or of sequences of measures probably Neither special remedial measures nor unusual never will be made easily. They must be based modifications of normal practices should be intro- on balancing medical assessments of probable duced, however, until responsible authorities have damage from radiation against the cost, along with declared that a state of emergency exists, making the resulting reduction in available food supplies, some kind of decontamination measures advan- and the economic and social dislocations. tageous or necessary. The usefulness of a particular remedial meas- For instance, it might become necessary to re- ure depends primarily on how well is does the job duce the radioactivity in small highly contami- it's supposed to do. Various possible methods al- nated areas, or in large areas generally blanketed ready have been experimentally investigated. by radioactive contamination. These situations Others remain to be studied. would require decontamination measures, drastic Field experiments have shown that when fall- modifications of usual practices, or a sequence of out is deposited on land where standing crops are 24 growing, no more than one-third of the deposit be expensive, in many areas may not be applicable can generally be removed from the land by har- and, with the procedures developed at this time, vesting the aboveground portion of the plants by not suitable for large areas. It might be useful mowing. if small clean areas are needed to produce food for Decontamination of soils is necessary primarily survival of people. for the removal of strontium 90. Other biologi- The effectiveness of decontaminating surface cally significant fisson products either are taken soil by scraping varies from being partially suc- up from soils by plants in much smaller amounts cessful for rough land to being highly successful or have such short lives that decontamination is for smooth land. Rough, freshly plowed surfaces not necessary. In zones of heavy strontium 90 are difficult to decontaminate. Scraping off 2 deposition, stringent decontamination measures inches of soil with a road grader may remove more will be necessary in order to reduce the strontium than 99 percent of the fallout from smooth soil, 90 content of the soil to a level acceptable for the but only 60 percent from rough soil. The latter production of vegetables and milk. (These prod- value is too low to justify the effort and expense. ucts absorb a greater percentage of the available Rough soil surfaces may be decontaminated more strontium 90 than do others.) completely by scraping off more soil or by repeat- For the production of other crops, or in zones of ing the scraping operation. Just as in harvest- lighter strontium 90 deposition, it may be sufficient ing, precautions against breathing dust and for to use less effective practices which reduce the cleanliness will be necessary. uptake of strontium 90 to a lesser degree. Obvi- The safe disposal of contaminated surface soil ously, heavily contaminated lands should be after removal is a serious problem. For the large placed in cultivation only when their use is abso- volumes of soil involved, the only practical places lutely necessary. In fact, the degree to which any for disposal appear to be pits in the center of small land is decontaminated must depend upon the fields or regularly spaced ditches across fields. availability of manpower, fuel, and equipment, The pits or ditches would have to be protected and most important, upon the need for more crop- from erosion and should not be used for crop land. The costly methods of decontamination production. now known would be used only in limited areas of intensively used croplands. Other Methods of Decontaminating Soil Several other methods of decontaminating soils Decontamination by Removal of appear to be even less practical on a field scale. Ground Cover and Crops Among them are leaching and cropping soils to Decontamination by the removal of ground remove strontium 90. Leaching would require cover is effective when the existing cover is thick extremely large amounts of water and calcium enough. Tests and experiments revealed that re- salts or acids. In addition to removing strontium moval of heavy contaminated mulches, 5 tons per 90, plant nutrients would be leached out of the acre, removed from 50 to 80 percent of the radio- root zone and would have to be replaced. Crop- activity even following irrigation. Kemoval of ping, even with those crops known to take up lighter mulches, 2 tons per acre, removed from 30 large amounts of calcimn and strontium, would to 50 percent. The cutting, rolling, and removal require more than 40 successive crops to achievo of sod contaminated with fallout resulted in a re- 90 percent decontamination. duction of radioactivity by over 90 percent. Standing crops usually provide less complete Reclaiming Soil by Deep Plowing ground cover, especially when young, and their Decontamination by deep plowing would be harvest may remove only a small fraction of the aimed at placing the contaminated surface soil fallout. Contaminated crops could be disposed 18 inches or more below the surface — or below of by harvesting and baling to reduce their bulk. the root zone of the plants that are to be grown. The bales must be stored where they will not In shallow-rooted crops, such as grasses and many vegetables, deep plowing might reduce the uptake contaminate other foods. The workers should of strontium 90 to about one-half of that under wear respirators to avoid breathing the dust normal cultivation. It will be most effective when created by these operations. Clothing should be the freshly exposed surface soil has a high sup- kept as clean as possible. Thorough washing of ply of calcium either naturally or by the addition the hands and face is necessary before eating. of lime or gj'psum. However, before the method Soil in greenhouses closed at the time of fallout is used, the situation in the area, the need for the deposition would provide a limited source of un- crops which may be grown, and the possible al- contaminated soil. ternatives should be carefully evaluated. Once strontium 90 has been plowed under, not only by Decontamination by Removal of deep plowing but also by normal tillage, future Surface Soil removal is virtually impossible. Further, the The removal of surface soil is one of the most productivity of some soils may have been drasti- effective methods of decontamination, but it would cally reduced by the deep plowing. 25 Effects of Radiation on PlantKand Seeds. The effects of radiation on plants and seeds dif- ment of wheat and barley will begin to be notice- fer ^Yidely, depending- upon age, moisture content, ably aflfected at a dose of about 5,000 rads and will state of metabolism, and for neutron irradiation, cease after a dose ten times that amount. Red chemical content. These factors may cause a ten- clover begins to lose its post-germination develop- tó twenty-fold ditl'erence in radiation sensitivity ment ability at about 15,000 rads, and it ceases in different kinds of seeds. altogether at 100,000 rads. Small seeded legumes appear to be very resist- Radioactivity stored in leaves and stems is many ant to radiation, while rice, tomato, and cotton times greater than that found in seeds. For ex- are moderately resistant. Rye and barley are ample, in wheat grown on artificially contam- moderately sensitive, while peanuts, soybeans, and inated soil, the leaves showed 11,422 disintegra- cowpeas are especially sensitive to injury from tions from strontium 90 per second per gram, gamma rays. compared with 638 in the grain. And most of this Sensitivity of seeds of different species varies so greatly that seeds of pine or onions, for example, was in the bran. In corn, the difference was even may be completely killed by 1,000 rads of gamma more striking. About 4,683 counts were observed rays, while seeds of alfalfa or flax tolerate more in the leaves and only 18 in the grain. The same than 100 times this amount. story held true for cesium 137. Total destruction of the ability of wheat, barley, The high radioactivity found in the leaves com- red clover, and millet to develop beyond the ger- pared with that in the seeds is in keeping with mination stage results from extremely high doses the high calcium or ash content in the leaves com- of radiation of seeds. Post-germination develop- pared with that in the seeds. SUMMARY OF EFFECTS OF FALLOUT ON AGRICULTURE

An evaluation indicates that the total effect of and water fiom fresh fallout contamination, farm radioactive fallout on American agriculture in families can prevent early internal radiation dam- case of nuclear attack would be serious. A series age when the intensity is at high levels. of nuclear explosions across the Nation would create hazards of severe radiation injury to farm Maximum Work Times people and their livestock. Radioactive contam- ination of food, feed, and water would increase Farmers who observe the maximum work times the hazard. Residual contamination in the soil suggested for alternating shelter and outdoors would continue the problem over a long period of work periods can gradually assume duties and yet time. still take advantage of recommended protection On the other hand, research is providing the against radiation injury. basic knowledge and specific means which can help to lessen the seriousness of these widespread ef- Food Decontamination fects. Knowing the radiation level in his area, Some of the food that has been contaminated can the farmer can take several protective and reme- be made safe for consumption by following sug- dial measures. gested methods for decontamination or by allow- Shelter ing time for sufficient decay of radioactivity. Such food could be used for farm families or the The most vitally important measure for the community, or salvaged for market. protection of farm families in time of emergency is to seek shelter quickly and stay there as long as Reclaiming the Soil recommended for the radiation intensity in the area, making short trips for only the essential Some severely contaminated farmland could be jobs or supplies. The interval between a warning mamtamed in production by diverting it to its of possible attack or the explosion and arrival of safest use, or by decontamination through the fallout may provide the time to get the family and method best suited to the conditions. livestock under cover. By taking advantage of These, then, are some of the safeguards avail- the protection provided by shelter, many families able now against fallout damage. Research on and their livestock could escape injury or death. radioactive fallout is being continued. New Food, Feed, and Water knowledge is expected to lead to improved methods of protecting American agriculture against haz- By protecting a sufficient quantity of food, feed, ards of fallout in time of emergency.

26 GLOSSARY (Definition of terms as they are used in this publication.)

ACCUMULATED DOSE: The total radiation CURIE : A unit for measuring radioactivity, equal dose resulting from repeated or prolonged to that produced by a gram of radium. (Micro- exposure. curie is one-millionth of a curie, and a micro- ACUTE EXPOSURE: Radiation exposure of microcurie or picocurie is one-millionth of a short duration. millionth of a curie.) ADSORPTION : The adhesion of one substance DECAY (RADIOACTIVE) : The decrease in ac- to the surface of another. tivity of any radioactive material with the pas- AIR BURST : The explosion of a nuclear weapon sage of time. See^HALF-LIFE. at such a height that the expanding fireball does DENIAL TIME: The period of time persons not touch the earth's surface. would be prohibited from entering a contami- ATMOSPHERE : The entire envelope of air sur- nated area or leaving shelter in such an area be- rounding the earth. cause of radiation intensity. Also, the period of ATOM: The smallest particle of an element that time croplands would be prohibited from use for still retains the characteristics of that element. designated agricultural products because of ATTENUATION (RADIATION): The absorp radioactive contamination, or milk prohibited tion and reduction of radiation intensity as it from human consumption because of radioiodine passes through any material. content. BACKGROUND RADIATION : Nuclear radia DISCRIMINATION: The natural discrimina- tion arising from within the body and from the tion against one chemical element in favor of surroundings to which individuals are always another by the biological systems of plants, ani- exposed in normal living. The main sources of mals, and man. An example is the discrimina- natural background radiation are potassium 40 tion against strontium in favor of calcium. DOSE: A (total or accumulated) quantity of in the body, potassium 40, thorium, uranium, ionizing (or nuclear) radiation. The term dose and radium present in rocks and soils, and cos- is often used in the sense of the exposure dose, mic rays. expressed in roentgens, which is the measure of BETA "RAY" (OR PARTICLE): A minute, the total amount of ionization that the quantity high speed particle with a negative charge and of radiation could produce in air. Tliis should originating in the nucleus of certain radioactive be distinguished from the absorbed dose, given elements. Physically the beta particle is iden- in reps or rads, which represents the energy tical with an electron moving at high velocity. absorbed from the radiation per gram of spec- BLAST: The effect in air of the liberation of a ified body tissue. Further, the biological dose, large amount of energy in a short interval of in rems, is a measure of the biological effective- time within a limited space. The liberation of ness of the radiation exposure. See RAD, this energy is accompanied by a great increase ROENTGEN. in temperature creating extremely hot gases DOSE RATE: The amount of dose of ionizing from the products of an explosion. These gases radiation to which an individual is exposed per move outward rapidly, pushing away the sur- unit of time (hour, day, week, or month). It rounding air with great force, and cause the is usually expressed as the number of roentgens destructive effects of an explosion. per hour. The dose rate is also commonly used BRIEF EXPOSURE : Exposure witliin the first to indicate the level of radiation intensity in a 96 hours. contaminated area. CELL: The fundamental unit of structure and ELECTRON: A very small particle of matter function in plant and animal organisms. carrying a negative charge. Electrons are pres- CONTAMINATION (RADIOACTIVE FALL- ent in all atoms surrounding the nucleus. In a OUT) : The deposit of radioactive material on neutral atom their number is equal to the num- the surface of land, structures, objects, human ber of positive charges (or protons) in the par- beings, animals, plants—entire areas—follow- ticular nucleus. ing a nuclear explosion. Plants may also be ELEMENT: One of the distinct, basic varieties further contaminated by absorbing radioactive of matter which, individually or in combination, material from contaminated soil or water; and have unique chemical characteristics. Ninety- animal products through the animal's consump- two naturally occurring elements have been tion of contaminated feed and water. identified in nature and about 10 others have COSMIC RAY: Any of the rays of extremely been produced as a result of nuclear reactions. high energy and penetrating power produced, EQUIVALENT RESIDUAL DOSE: The ac- it is believed, by electric action in interstellar cumulated exposure dose of gamma radiation space (beyond the earth's atmosphere). They corrected for such recovery as has occurred at bombard the earth from all directions. any particular time. 27 FALLOUT : Dustlike particles of radioactive mat- IRRADIATI0i*4Exposu£ßJ:u_xadiatiear ter created by a nuclear explosion. The term is ISOTOPES: FoiTOsof the same element which also used to describe the process of the fall back usually have identical chemical properties but to earth of the contaminated particles from the which differ in their atomic masses (because bomb cloud. they have a different number of neutrons in FIREBALL: The luminous sphere of hot gases their respective nuclei). They may be stable which forms a fraction of a second after a nu- (nonradioactive) or they may be radioactive. clear explosion and immediately starts to ex- KILOTON NUCLEAR BOMB: A nuclear bomb pand and cool. which produces the same amount of energy as FISSION (NUCLEAR FISSION) : The proc- 1,000 tons of TNT. ess in which the nucleus of an atom of a heavy MAXIMUM PERMISSIBLE EXPOSURE : As element; for example, uranium, splits into (gen- applied to postattack emergency operations, the erally) two nuclei of lighter elements, with the total amount of ionizing radiation exposure release of large amounts of energy. which it is believed a normal person may receive FISSION PRODUCTS : A general term for the without the harmful effects outweighing poten- complex mixture of radioactive substances pro- tial benefits. duced as a result of nuclear fission. (The mix- MEGATON NUCLEAR BOMB: A nuclear ture contains over 200 diiïerent isotopes of over bomb which produces the same amoimt of 35 elements.) energy as 1,000,000 tons or 1,000 kilotons of FOOD CHAIN: The route of nutrients from the TNT. soil through plants and animals, and through MIDLETHAL DOSE (MEDIAN LETHAL the biological system of man as human nutri- DOSE, OR MLD) : The amount of ionizing ra- tion. diation over the entire body which is expected GAMMA RAYS: Electromagnetic radiation of would be fatal to 50 percent of a large group high energy emitted by the nucleus of an atom. of a given species of living creatures or organ- These rays accompany many nuclear ]-eactions isms within 30 days. It is commonly (although including nuclear fission. Physically, gamma not universally) accepted that 450 roentgens rays are identical with X-rays. The only es- is the midlethal dose for human beings. sential difference is that X-rays do not originate MOLECULE: The smallest group of atoms that in the nucleus of an atom. can exist isolated from other like groups, as in a GEIGER COUNTER: An instrument for meas- gas or in a solution. The molecule of a com- uring radiation rate. As usually constructed it pound contains more than one kind of atom. is a highly sensitive instiiunent with a very The molecule of an element consists of one or short range of measurement that would be use- more like atoms. ful only for monitoring low levels of intensity NEUTRON: A neutral particle of matter (with such as for food, water, and personnel. no electrical charge) present in all atomic nu- GENETICS : The branch of biology dealing with clei except those of ordinary hydrogen. heredity and variations from one generation to Neutrons are required to initiate the fission proc- another. ess, and large numbers of neutrons are produced HALF-LIFE : Time required for a radioactive in nuclear explosions. The short path and life substance to lose 50 percent of its radioacti^-ity. of neutrons from a detonation limit their Decrease of radioactivity is usually referred to damage to initial radiation at the time of the as decay. explosion, and they do not contribute to residual INITIAL RADIATION: Nuclear radiation fallout radiation hazard. Neutrons present emitted from the fireball and atomic cloud dur- little hazard ouside the area of heavy blast ing the first minute after a nuclear explosion. damage. INTENSITY (RADIATION) : The term is used NUCLEAR RADIATION: Radiation emitted loosely to express exposure dose rate of radiation from atomic nuclei in various nuclear proc- at a given location. For example, the intensity esses. The types of radiation discussed in this of radiation at the location could be expressed in publication are beta rays and gamma rays. the number of roentgens per hour measured by (Other radiations important in the results of an appropriate instrument at that point. nuclear explosions are alpha rays and neu- ION: An electrically charged atom or molecule, trons.) All these nuclear radiations are, or re- either positive or negative. sult in ionizing radiations, but the reverse is not lONIZATION: The process by which a neutral true. For example. X-rays are ionizing radia- atom or molecule matter receives an electrical tions, but they are not nuclear radiations be- charge, either positive or negative. cause they do not originate in the nucleus of an IONIZING RADIATION: Radiation capable of atom. See—IONIZING RADIATION. producing ions either directly or indirectly as NUCLEAR WEAPON (OR BOMB) : A general It passes through matter. Passage of ionized name given to any weapon in which the ex- radiation through living cells causes biological plosion results from the energy released by re- damage. actions involving the nuclei of atoms. Thus, 28 both atomic bombs and hydrogen bombs are in RADIOSTRONTIUM (RADIOACTIVE fact nuclear weapons, and the tei-m is used to STRONTIUM) : Strontium in which the nuclei inchide both types in this publication. of the atoms emit radiations. NUCLEUS (OR ATOMIC NUCLEUS): Tlie RESIDUAL RADIATION: Nuclear radiation, core of an atom that carries most of the mass clnefly beta and gamma rays, which persists and the total positive electrical charge. AH longer than 1 minute following a nuclear ex- atomic nuclei (except ordinaiy hydrogen) con- plosion. The radiation is emitted mainly by tain both protons and neutrons (positively the ñssion products and other bomb residues charged and neutral particles). The electrons in the fallout. (negatively charged particles) of ai\ atom are ROENTGEN: A unit for measuring a radiation outside the nucleus. exposure dose. PROTECTION FACTOR: The relative reduc- SHELTER (FALLOUT): A specially con- tion in the amount of radiation that Avould be structed refuge, or the use of normal buildings received by a person in a protected location, or materials primarily for the purpose of pro- compared with the amount he would receive if tecting people, livestock, or other living organ- he were unprotected. isms from the gamma radiation resulting from PROTON : A particle of matter carrying a posi- fallout. tive charge. It is identical physically .with the SHIELDING : Any material or obstruction which nucleus of the ordinai-y hydrogen atom. All absorbs radiation and thus helps to protect atomic nuclei contain one or more protons. people and livestock from the effects of radio- RAD : A unit for measuring an absorbed dose of active fallout. A considerable thickness of ma- radiation. terial of high density may be needed. RADIATION: See—NUCLEAR RADIATION. STRATOSPHERE : The part, of the earth's at- RADIATION SICKNESS: A disease resulting mosphere extending from the troposphere (ap- from excessive exposure of the entire (or a large proximately 7 miles above the earth) to alti- part) of the body to ionizing radiation. Some tudes as great as 45 to 50 miles. (See—TROPO- early symptoms are nausea, vomiting, and diar- SPHERE.) rhea, which may be followed by loss of hair, SURFACE BURST: The explosion of a nuclear hemorrhage, inflammation of the mouth and weapon at the surface of the earth, or at a throat, and general loss of energy. In severe height above the surface close enough for the cases, where the radiation exposure has been fireball to touch the land or water. The effect relatively large, death may occur within 2 to 4 of fallout is most serious following a surface weeks. Those who survive 6 weeks after the burst. receipt of a single dose of radiation may gen- TROPOSPHERE : The lower part of the earth's erally be expected to recover. atmosphere, characterized by formation of clouds and precipitation. Typical upper limits RADIOACTIVITY : The spontaneous disintegra- of the troposphere are about 6 miles in the polar tion or nuclear change of certain atoms in which regions and 9 to 12 miles near the equator. energj' is released. The process is accompanied (See—STRATOSPHERE.) by the emission of one or more types of radia- UNDERGROUND BURST: The explosion of a tion, such as beta and gamma rays. nuclear weapon with its center beneath the RADIOIODINE (RADIOACTIVE IODINE): surface of the ground. Iodine in which the nuclei of the atoms emit UNDERWATER BURST: The explosion of a radiations. nuclear weapon with its center beneath the sur- RADIOISOTOPE : See^ISOTOPES. face of the water.

29 APPENDIX A Measurement of Fallout Radiation

Monitoring is essential to determine the degree Rate meters are used to measure radiation of contamination of personnel, objects, facilities, rates in an area. They are basically reconnais- food and water, as well as to determine where in sance instruments to measure the radiation dose the general environment decontamination is re- rates across an area or near items that might be quired and the effectiveness of decontamination contaminated. Such measurements are essential measures. Monitoring senñces and information as a basis for evaluating potential occupancy of must be available to fanners and agricultural offi- areas, utilization of. materials, or need for decon- cials to help them determine their ability to con- tamination. They might be used in three ways: duct essential fami activities. (a) For field station monitoring; scheduled In agreement with national defense plans, pro- measuring and reporting of dose rates at a pre- grams,"and operations of the Department of De- determined point outside a sheltered location. fense, under Executive Order No. 10952, the (b) For aerial surveys to enable general esti- Department of Agriculture is responsible for mation of radiation levels over a wide area. developing plans for a national program, direct- (c) For detailed monitoring of areas, facil- ing Federal activities, and furnishing technical ities, objects, and materials after radioactive decay guidance to State and local authorities concerning has reduced dose rates to a level permitting ex- protective measures, treatment, and handling of tended field activity. the following, any of which have been exposed to The Office of Civil Defense, Department of De- or affected bj' radiation : fense, has developed monitoring instruments or (1) Livestock, including poultry. rate meters to be used for survey purposes in the (2) Agricultural commodities on farms or event of emergency operations. Examples of in- ranches. struments having the widest application are : (3) Agricultural lands. (a) The low-range beta-gamma survey meter (4) Forest lands. (CD V-700) is a Geiger counter type. It is a (5) Water for agricultural purposes. highly sensitive instrument and is suitable for (6) Äleat and meat products, poultry and poulti-y products in establishments mider the con- emergency monitoring of food, water, and person- tinuous inspection of the U.S. Department of nel. It has a measurement range from 0 to 50 mil- Agriculture. liroentgens per hour. (A milliroentgen is one- (7) Agricultural commodities and products thousandth of a roentgen.) Such a short range owned by the Commodity Credit Corporation or of measurement would be of little use in an area by the Secretary. with significant contamination, since a relatively The intensity of gamma radiation from fallout low level of radioactivity would drive the indi- at any given time and location is expressed in cator needle off the scale unless the Geiger tube and terms of a unit of measurement called a "roent- sample were exposed in an adequate shield. gen." It is an accepted unit for measuring radia- (b) A medium-range gamma survey meter (CD tion in air, just as a calorie for heat or a kilowatt V-710)^ would be most widely useful for general hour for electricity. The roentgen is used in two radiological monitoring following attack. The different connotations: (1) Total accumulated measurement range is from 0 to 50 roentgens per radiation exposure is expressed merely as so many hour. The instrument is designed for ground sur- roentgens, and (2) the rate of radiation exposure given off by fallout or any other nuclear radiation vey where the radiation levels would be expected source is expressed as roentgens per luiit of time to change relatively slowly. Until a special instru- (per hour, minute, or second.) ment is available, it will be used for aerial survey. The human senses do not detect ionizing radia- (c) A high-range beta-gamma survey meter tion. Special instruments have been developed (CD V-720) would be required in areas where for the detection and measurement of various nu- clear radiations. ' In future procurement of instruments by the OflSce of Civil Defense, the CD V-710 survey meter will be replaced These devices can be divided into rate meters by a CD V-TIS, Radiological Survey Meter, gamma only, and dosimeters: 0-0.5, 0-5, 0-50, 0-500 roentgens per hour. 30 FiGTiBE 10. A Geiger counter is a monitoring device used to detect and measure radioactivity. Its range of measure- ment is very small, but in time of emergency it would be useful for monitoring food, water, and personnel. contamination levels are extremely high and for (b) CD V-Y40,* with a measurement range making high level beta radiation measurements. from 0 to 100 roentgens. This instrument has a measurement range from As part of the Nation's preparedness program, 0 to 500 roentgens per hour. the Federal Government is assisting the States and Dosimeters are used to measure accumulated their political subdivisions to develop systems for dose of radiation in an area or the accumulated exposure of people and livestock. Self-mdicating dosimeters have been developed. Two examples * In future procurement of instruments by the OfBce are: of Civil Defense, the CD V-740 dosimeter will be replaced (a) CD V-730, with a measurement range by a CD V-742, Radiological Dosimeter, self-reading, from 0 to 20 roentgens. gamma only, 0-200 roentgens. 31 }

FIGURE 11.—A medium-range gamma survey meter (above) would be generally used to determine the intensity of radioactivity at ground level following an attack. postattack radiological monitoring and reporting. and location of radiation becomes available, it Kits of instruments are made available to the will be broadcast on radio stations. States when monitors are trained and qualified for Details of local, State, and national radiological emergency operations from slieltered locations. defense systems are beyond the scope of this report Financial assistance is also given for the procure- and are described in the Office of Civil Defense ment of some types of communications equipment for civil defense purposes. publications listed under "Publications and Films," page 140. Information resulting from plotting, analysis, and evaluation of reported radiological data will As a supplement to organized Federal, State, be used as a basis for the control of radiation ex- and local monitoring systems, every home and posure during emergency operations, and for community shelter should have an instrument to warning and instruction of the public. measure radiation dose rate—a ratemeter. In the In the event of a nuclear attack, States and event of a nuclear attack, such an instrument local civil defense organizations M-ould be responsi- would provide information that will help the user ble for scheduled periodic radiological monitor- determine the degree of fallout danger he faces, ing and reporting. As information on intensity and help him make logical decisions for greater 32 FiGUBE 12.—A dosimeter measures the accumulated dosage of radioactivity. safety. For example, a citizen's radiation instru- be useful for keeping track of accumulated radia- ment should help the user determine when to take tion exposure over a long period. A reasonable shelter, when to leave the shelter, and how long range for a citizen dosimeter is from 0 to 600 it would be advisable to remain in an improtected roentgens. area. The instrument also should be of value in Instruments having all of the essential and most locating that portion of the home or protective of the desirable characteristics described are com- structure that offers the best protection from mercially available. Other instruments, designed fallout. on the basis of these characteristics, are being In addition to a ratemeter, a dosimeter would developed.

33 APPENDIX B Protection Factors

TABLE Q.—Descríption of shelter categories with TABLE 7.—Types of buildings that will provide associated protection and attenuation factors ^ approximately the stated attenuation for loose- housed livestock and poultry ^ Shelter Common examples * cate- I Protection factor i Atten- gory Item uation Types of buildings factor 1,000 or greater OCD underground shelters. Subbasement of multistory (better than 0. 0125 a. Large barn (50' X 80' minimum); 0.001). buildings. full bank on 3 sides; heavy solid Underground installations concrete or stone wall on fourth side; (mines, tunnels, etc.). few doors and windows; 6 feet 250 to 1,000 OCD basement fallout shelters baled hay ^ above basement. (0.004 to (heavy masonry residences). 0.001). 025 a. Large barn; half bank; solid concrete Basements (without exposed or stone foundation; few doors; walls) of multistory build- windows above animals' backs; over ings. Central areas of upper floors 12 feet baled hay above. (excluding top 3 floors) of high-rise buildings ' with 05 a. Large barn; half bank, cinder block heavy floors and exterior foundation; windows above cattle; walls. 12 feet baled hay. OCD basement fallout shelters b. Large barn; gambrel roof; two-story 50 to 250 (0.02 on cinder blocks; no windows and few to 0.004). (frame and brick veneer residences). doors; full of baled hay (gambrel Central areas of basements roofs retain less fallout than do gable (with partially exposed walls) roofs). of multistory buildings. As in la, empty of hay. Central areas of upper floors (excluding top floor) of mul- 075 a. As in 2a, empty of hay. tistory buildings with heavy b. Full cinder block ground floor; 25 floors and exterior walls. feet baled hay. D 10 to 50 (0.1 to Basements (without exposed 0.02). walls) of small 1- or 2-story a. Large barn; fuU masonry ground buildings. floor; no windows; empty. Central areas of upper floors b. Large barn; one-half bank; cinder- (excluding top floor) of mul- block foundation; 12 feet baled hay. tistory buildings with light floors and exterior walls. a. Large barn; full frame; no foundation 2 to 10 (0.5 to Basements (partially exposed) above floor; 25 feet baled hay. 0.1). of small 1- or 2-story build- b. Hog house; solid concrete walls, no ings. windows; metal roof. Central areas on ground floors c. Poultry house; first floor only of large in 1- or 2-story buildings multistory masonry construction; with heavy masonry walls. windows 3 feet above floor. 2 or less (0.5 or Aboveground areas of light poorer). residential structures. Medium-sized frame barns; no foun- dation above floor; 25 feet baled hay. Very large frame barns; two-story; ' This term expresses the relative reduction in the 2-foot foundations; few windows; amount of radiation that would be received by a person in empty of hay. a protected location, compared with the amount he would Full cinder-block barns if empty; receive if he were unprotected. The reciprocal of the cinder-block hog barns with metal protection factor is called the attenuation factor. roof. ' These examples refer to isolated structures. d. Large frame barn; one-half bank on ' For the purposes of this example, "high-rise" buildings cinder block; empty of hay. are those greater than about 10 stories; multistory build- ings are those from 3 up to about 10 stories. Very large, all frame, two-story barn; Source: Adapted from Appendix 2, Annex 10, National empty of hay. Shelter Plan NP 10-2, OCDM, May 1960. See footnotes at end of table. 34 TABLíB 7.—Types of huildings that will provide TABLíB 7.—Types of buildings that will provide approximately the stated attemtation for loose- approximately the stated attenuation for loose- housed livestock and poultry—Continued housed livestock and poultry—Continued

Atten- Atten- Item uation Types of buildings Item uation Types of buildings factor factor

b. Very large quonset-type barn; full of 11 Smaller poultry houses with consider- confined stock. able openings. c. Larger sheep sheds, hog houses, and Sheds on side of larger buildings, very large one-floor poultry houses; considerable openings; stock confined. limited openings; full of confined Top floor of barn converted to mul- stock. tiple-floor poultry house. a. Medium-sized barns with haylofts; 12 Smaller sheds with large side open; frame; few windows; low foundations; animals confined. empty. Smaller poultry houses and shelters; b. Barns in items 7 and 8 with asphalt many openings. or flatter roofs with high fallout retention. 13 .9 Open sheds; animals free to run in c. Cinder block or tile low poultry shed or adjacent small lot only. houses and hog houses, if asphalt roof or other retentive types. 14 1.0 No significant shelter-free running or d. Larger one-floor poultry houses with grazing animals. These values as- Umited openings. sume loose housing of animals or e. Midfloors of multistory poultry poultry; animals confined in stalls houses, including large frame barns near doors and low windows would converted to poultry houses. have far less protection than would f. Any farm building giving shelter those in the most protected areas in equivalent to first floor of a two-story the building. frame dwelling with normal windows.

10 a. Very large "pole sheds," open on low side ; animals confined under roof. b. Large poultry houses; one floor; nu- 1 Based on calculations and guides provided by Neil merous openings that can be covered FitzSimons, Office of Civil Defense, Department of with canvas. Defense. c. Smaller poultry houses with few 2 As shielding material, 6 feet of hay are equivalent to 1 windows. foot of water or about 7 inches of earth.

35 APPENDIX C 40 Cow Dairy Barn and Family Fallout Shelter

Protection for highly valued livestock should shelter exterior walls should conform to standards be considered along with the fallout shelter for of the Office of Civil Defense, Department of the rural family. In many respects, fallout pro- Defense. tection requires"structural characteristics opposite The main features of the plan are : of those found in efficient farm buildings. This (1) The family shelter is built-in. This gives plan is a compromise between a relatively high construction economy over a separate family shel- degree of protection for livestock, and a reason- ter, and allows the dairy operator to continue work ably efficient dairy operation under normal during a fallout emergency without exposure to conditions. outside radiation levels. All exterior walls should be at least 12 inches (2) A thick layer of earth is placed overhead thick and of a dense material such as poured con- as a shield against fallout on the roof. crete, stone, concrete block or brick with cores (S) Mechanical feeding reduces operator time filled with mortar or earth, or pressure treated outside the family shelter, and all stored feed ia wood with space between filled with sand. Family manually accessible inside the barn.

GASOLINE SroHAGE

FE£D\ BIN3 SmAW ^ HAY STORAGE

WALL -j LI TTER AL LEY

A/J? //t/TAATA FEED ALLEY •"1 f IT T n~T'' éíAj:LG_E^^_ LITTESÍ ALLEY ^

PLAN

^SECTION FIGURE 13.—40 cow dairy barn and family fallout shelter. 36 (•4) Other livestock could be temporarily stored forage is relied upon for shielding, a thick- housed, fed, and watered inside. ness of several feet should be maintained. Or- (5) Stored hay and straw are placed for shield- dinary glass windows and wood doors have very ing effect. Outside doors are to be temporarily little shielding value, and must be blocked with shielded with water-soaked bales. more material. A minimum area of glass block (6) The ventilating air is filtered and flow rate serves as windows in the plan, and local milk is adjustable. Air to the family shelter can be sanitarians should be consulted for lighting supplied by direct duct or by leakage from the requirements. barn. bhielding values of the structure are evaluated (7) An auxiliary generator assures electric according to "Fallout Shelter Surveys: Guide for power, although it is anticipated that many areas Architects and Engineers," National Plan Appen- will not lose commercial power. dix Series, NP-10-2. The percentage of outside (8) The water supply pump is inside the bam. radiation entering the structure increases greatly Tanks not shown on the plan, are covered and if essential construction features are omitted. vented several feet above ground to exclude set- Percentage o/ tling fallout. outside radiation A rough estimate of protection from radioactive Family fallout is given by the weight of all materials be- Construction Barn shelter tween the fallout and the shielded space. Below As shown on plan 0.9 0.3 Doors not shielded with wet hay bales 3. 0 .3 ground construction and earth banks increase the Overhead sand replaced by baled hay 10. 7 3.7 protection of a concrete wall several times. If Glass block replaced by ordinary windows- 1. 3 .4 TRENCH-TYPE SHELTER ARRANGEMENTS (A, B, C, D) Roofs for Trench-Type Fallout Shelters

Trench silos can be converted to fallout shel- entrances as shown on the sketches, give a radia- ters by adding an overhead earth shield and a tion reduction factor of 0.0023. This is a protec- baffled entrance. The long, narrow shape facili- tion factor of over 400. It is worthwhile to note tates bridging to support overhead shielding and that a 1-foot thickness of earth will admit 13 times minimizes radiation penetration through open- as much radiation as a 2-foot thickness. ings. A 2-foot thickness of earth overhead and (E, F) Fallout Protection in Buildings

A building constructed as in the sketches would source of radiation inside and flushing would be provide a reduction factor of about 0.025. Neces- necessary to obtain the stated reduction factor. A sary conditions for obtaining this protection in- flushing system must provide for rapid runoff clude walls banked with earth to sill level, away from the building to avoid pile-up of fallout protected stock kept below sill level, and tightly around the walls. closed doors. Further improvement in shelter A hay mow with 10 feet of baled hay will give value can be accomplished by reducing or elimi- overhead shielding about equal to 1 foot of earth. nating windows and doors and by full earth banks Also, the steep gambrel roof will retain less fall- around outside walls. out. Hay mows and other feed storage spaces With 2 feet of earth overhead, very little radia- should be tightly weathersealed to prevent tion would penetrate the roof. With only 1 foot contamination. of earth, fallout on the roof would be the main

37 A.ARCHED B. PITCHED Commercial Metal Components Three-Hinged Arcti or Trussed Rotters

C. FLAT D. FLAT Logs,Wire Mesti and Straw Posts, Beoms and Joists ROOFS FOR TRENCH-TYPE FALLOUT SHELTERS CROSS SECTIONS SHOWN ON TYPICAL CONCRETE-LINED SILOS A 2-Foot Loyer of Eorth Will Provide It is Important that the Roof Structure a Protection Factor of About 400 and be Carefully Designed to Safely Support Will Weigh from 200 to 250 Lbs. Per all Live and Dead Loads. Square Foot of Roof Area.

RIDGE SPRINKLER PIPE FOR FLUSHING ROOF

E. ONE-STORY BUILDING F BANK-TYPE DAIRY BARN The Depth of the Sard or Earth Fill Will A 15 Foot Depth of Tightly Boled Hay Will be Limited by the Strength of the Ceiling Provide Shielding About Equal to o 2-Foot Structure. Layer of Earth, but the Depth Should be Supply Generous Quantities of Water for Reduced if Necessary to Avoid Over-loading Decontaminating. Drain Contaminated the Mow Floor. Water Away for the Lots. FALLOUT PROTECTION IN BUILDINGS Bank Earth up to Sill Height on all Exposed In New Construction, Openings Should be Kept Walls and Protect Against Erosion. to a Minimum, Window Sills Should be High Windows and Doors May be Closed With and the Mow Floor or Ceiling Structure Must Concrete Blocks or Sondbogs. be Designed to Support the Heavy Load of Shielding Material. A Concrete Mow Floor Increases Shielding.

38 EXHAUST VENT STACK OVER >«ííí;'^V;í,*':>VA.., ..

-BALED HAY, CATTLE UP TO ROOF

I REMOVABLE WALL SECTION

ENTRANCE, DRAIN AND AIR INTAKE SILO

SILO

-SILAGE PACKED $, L-SHAPED MOUNDED TO DRAIN TO EACH SIDE VENT 4 ESCAPE Zll --EXTEND ROOF FAMILY OVER LOWER END OF SILO zn- EXHAUST VENT STACK OVER

-7 I I ^^—EXHAUST VENT ' STACK OVER - FAMILY CATTLE SILO

CATTLE

VENT Í. J ESCAPE^

■ BALED HAY, >v UP TO ROOF -, SANDBAGS OR EARTH FILLED ^, BULKHEAD

ENTRANCE, DRAIN -ENTRANCE, DRAIN AND AIR INTAKE AND AIR INTAKE IN-LINE PARALLEL Silos to be Sealed with Plastic Sheeting and Covered with Sowdusf or other Suitable Ballast. All other Areas tobe Roofed and Covered with Two Feet of Eorth Sodded or otherwise Protected from Erosion. TRENCH-TYPE SHELTER ARRANGEMENTS 39 PUBLICATIONS AND FILMS Publications

Office of Civil Defense, Department of Defense NP-10-2—Fallout Shelter Surveys, Guide for Architects and Engineers. BULLETINS : Permissible Emergency Levels of Radioactivity U.S. Atomic Energy Commission in Water and Food (September 1955). The Eiïects of Nuclear Weapons. U.S. Depart- Emergency Measurements of Radioactivity in ment of Defense and U.S. Atomic Energy Com- Food and "Water (December 1952). mission (April 1962). Radiation Physics and Bomb Phenomenology (Rev. Jmie 1959). U.S. Department of Agriculture Radiological Defense Planning and Operational Farmers' Bulletin 2107—Defense Against Radio- Guide. active Fallout on the Farm (Revised April Fallout Protection. 1961). Family Shelter Designs. Home and Garden Bulletin No. 77—Family Food Office of Emergency Planning Stockpile for Survival (August 1961). NP-10-1—Fallout Shelter Surveys, Guide for USDA Radiological Training Manual (Rev. July Executives. 1961). Films

U.S. Department of Agriculture #5—Fact and Fable Fallout and Agriculture. Color; time: 23 min. #7—The Unseen Enemy Released 1960. (Prints available from the Mo- #8—Radiation and the Body tion Picture Service, Office of Information, U.S. The following films are current, but are to be Department of Agriculture, AA^ashington 25, used for TRAINING ONLY: D.C., and Film Service Libraries of all State Colleges of Agriculture.) Mission Fallout Nerve Gas Casualties and Their Treatment Office of Civil Defense, Department of Defense Trapped The following films are CURRENT and may A new catalog is now being prepared which will be obtained from your nearest LT.S. Army Central contain detailed information on content, type, and Film and Equipment Exchange : prices of all current OCD films. AAHien this publi- Civil Defense in Schools cation is available, its release will be announced Crisis through an Information Bulletin. Emergency Hospital SERVICE AREAS OF U.S. ARMY CEN- Fallout TRAL FILM AND EQUIPMENT House in the Middle, The (6I/2 mm.) EXCHANGES House in the Middle, The ( 12 min.) First U.S. Army Central Film and Equipment In-^asible Enemy, The Exchange, Governors Island, New York 4, Lifeline of the Nation N.Y. No Time To Lose Operation Cue (Short, silent version) Connecticut New Jersey Operation Cue (Long, silent version) Maine New York Operation Cue—Revised (Color, sound) Massachusetts Rhode Island Radiological Defense New Hampshire Vermont Rehearsal for Disaster Second U.S. Army Central Film and Equipment Ten for Sur^-ival : Exchange, Ft. George G. Meade, Md. #1—Enter the Nuclear Age Delaware Pennsylvania #2—Knowledge Is Survival Kentucky Virginia #3—Biography of a Disaster #1 Maryland West Virginia #4—Biography of a Disaster #2 Ohio 40 Third U.S. Army Central Film and Equipment Nevada Utah Exchange, Ft. McPherson, Ga. Oregon Washington Alabama North Carolina Florida South Carolina Military District of Washington, Central Film Georgia Tennessee and Equipment Exchange, Ft. Myer, Va. Mississippi District of Columbia, Greater Washington, D.C., Area. (All requests from Maryland Fourth U.S. Army Central Film and Equipment and Virginia outside this area should be sent Exchange, Ft. Sam Houston, Tex. to Second U.S. Army Central Film and Arkansas Oklahoma Equipment Exchange as indicated above.) Louisiana Texas New Mexico U.S. Army Caribbean, Central Film and Equip- ment Exchange, Corozal, C.Z. Fifth U.S. Army Central Film and Equipment Exchange, Ft. Sheridan, 111. Canal Zone VirgÍ2i Islands Colorado Missouri Illinois Nebraska U.S. Army Forces Antilles, Central Film and Indiana North Dakota Equipment Exchange, Ft. Brooke, P.R. Iowa South Dakota Puerto Rico Kansas Wisconsin Michigan Wyoming U.S. Army Pacific, Central Film and Equipment Mimiesota Exchange, Schofield Barracks, Hawaii Sixth U.S. Army Central Film and Equipment Hawaii Exchange, Presidio of San Francisco, San Guam Francisco, Calif. U.S. Army Film and Equipment Exchange, Arizona Idaho Fort Richardson, Alaska California Montana Alaska

U.S. GOVERNMENT PRINTING OFFICE. 1962 O—644700 41