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NATIONAL WORKSHOP ON PROTECTION AND WASTE MANAGEMENT 17 - 21 MARCH, 1997

Organized By

FEDERAL RADIATION PROTECTION SERVICE, IBADAN

and

NATIONAL AGENCY FOR FOOD AND DRUG ADMINISTRATION AND CONTROL (NAFDAC), ABUJA

at the

FEDERAL RADIATION PROTECTION SERVICE Department of University of Ibadan, Nigeria

TOPIC: AND MAN - MADE

AND

SOUCES OF RADIATION

By

Professor Ayo Babalola Federal Radiation Protection Service, Department of Physics, University of Ibadan, Nigeria

3 0-28 L 2.

I. Introduction

There is a history of up to 50 years of the development of man's use of the atom, and today this industry can be considered as matured technology. However the benefits that have resulted from the use of the atom are not without consequences which are of concern. For few topics have commanded as much attention from all quarters (scientists governments and the general public) as the management of the use of the atom.

Ionizing radiation which results from the breaking of the atom is a form of energy, and on account of its ionisation effects, it constitutes hazard to all biological systems, hence the general concern. This concern is born-out of the fact that ionising radiation release (without control) is more potent than the hurricane or earthquake, whose passage is only known by the effects they leave behind.

In our discussion of the sources of ionising radiation that are man made, we have to identify the human - needs that led to this peculiar venture which ironically is now viewed in same way as the opening of the pandora box.

II. Human needs and Ionising Radiation

Human needs continue to increase the use of many sources of ionising radiation. They turn out to be the most effective and reliable tool to solve specific human problems. In most, if not all these cases, the benefit derived outweighed either the level of damage, or the hazards involved in their applica­ tion. These will be summarised under four headlines.

1. Food and Agriculture

The use of radiation (in form of control exposure to radioisotope and other nuclear techniques) has been to solve important agricultural problems which have defied known convectional methods. They are aimed to

(i) produce high yielding, high - protein varieties of food crops.

(ii) produce and weather - resistant crop vari 'lies

(iii) make efficient use of water resources

(iv) Determine fertilizer uptake efficiency and optimize nitrogen fixation.

(v) Control or eliminate insect pests. 3.

(vi) prevent losses of crops during storage

(vii) improve productivity and health in domestic animals

(viii) protect the agricultural environment and (ix) Extend the shelf-life of food through irradiation.

The application of radioisotopes and radiation technique under strict regulation have proceed better than traditional methods. Nearly 1000 crops varieties derived from radiation induced mutations today are grown on several million hectares, yielding economic gains estimated in the billions of dollars. The use of radiation techniques in pest control has helped fight the lost of crops to insects and loss of livestock from spread by insects. In most of these cases, the insects are sterilized by radiation in cases when the insects became resistant to chemical use or replace poisonous insecti­ cides which pollute the environment.

2. Industry

Radioisotopes as tracers are used for many aspects of manufacturing. Radioisotope thickness gauges are used in the making of continuous sheets of materials (paper, plastic, film metal etc) when it is desirable to avoid contact between the gauge and material .

Radiation processing, which involves the use of conven­ tionally produced X-rays, gamma-rays (Colbalt - 60) or high energy electrons, has grown at a steady rate of 10-15% per year. More than 135 industrial gamma irradiators and about 400 electron beam machines are operating in about 42 countries. The estimated total value of products processed using radiation is at more than two billion dollars. The radiation processed products include foodstuffs, hospital and medical supplies, various plastics, rubber products, and wire and cables.

3. and

The impact of radiation X-rays and radioisotopes in medicine has grown rapidly. Screening, diagnosis , prognosis and , to varying degrees, have benefitted from this development. More recently other important techniques such as nuclear magnetic resonance and the use of advanced X-ray technology in digital involving computerised and have been introduced. In addition a field known as Nuclear Medicine now exists which includes 4.

advanced techniques in nuclear . All these supplement the age-old isotopic methods which are still in use. For diagnostic purposes alone many million tests are made each year, such that a third of all hospitals patents benefit from the use of nuclear medicine. The use of radio­ in medical therapy are standard. is used in in the treatment of some types of thyroid cancers which cannot be moved by operation. Other cancers are often treated using gamma-rays from Cobalt - 60 sources, while sealed radioactive sources, such as - 226, irridum - 192, and cesrum - 137 and Cobalt-60 are used for brachyth. Sterilization of medical product such as surgical dressings, sutures, catheters and syringes are routine procedures.

In summary an estimated 10,000 gamma-earneras-imaging instruments used in combination with radioisotopes in are installed world-wide, supporting a range of nuclear medicine procedures. In many countries nuclear medicine has become routine in hospitals that up to one in every four patients use it. In the U.S. more than 10 million procedures are performed annually.

Finally, we will like to identify the development of vaccines against parasitic affect more than 900 million people in the tropical zones. Nuclear techniques are for diagonosis of liver and thyroid diqeaseg, and human nutrition research of trace element deficiencies such as iodine deficiency- which in Asia alone affects more than 400 million people. The attendant problem will be examined later under waste disposal problems.

4. Energy - Environment and Research

The energy production is perhaps tiu. most visible and controversial peaceful use of the atom. plants produced one-third or more of the total electricity in 11 3 countries in 1988 . Percentage of total electricity supplied by nuclear power ranged from 70% to 15% in 16 countries. There are 429 nuclear power reactors connected to electricity grids which accounted for 17% of the world's total electricity production. Less noticed in the energy field are other applications of nuclear energy in the oil and gas industries. Table 1 shows the national percentages of nuclear production for the year 1985-88 collected frpm IAEA sources^. 5.

In operation are 326 nuclear research reactors used to support work in many science oriented disciplines. These are used in 55 industrialised and developing countries as a training tool, and produce radioisotopes used in industry, agriculture and medicine.

Energy trends today are pointing towards an increase, in the installation of power reactors despite recent mounting campaigns. The issue of greenhouse effects arising from gases emitted from convecti'onal electricity plants has increased the environmental appeals to opt for cleaner power generators. In addition the comparative environmental costs of different energy sources has called for the use of nuclear power for electricity generation that do not emit carbon dioxide.

The availability of fresh water has been national problems of many countries especially in sub-sahara Africa and Middle-East. Underground water reserves exist, but never reached the surface because not enough is known about their quantity, and development potential to make it economic to exploit them. Nuclear techniques using radioisotopes are precise modern tools for the study of water resources. They provide adequate information on the origin, distribution, age and properties of water in a given region.

Human mining and milling of radioactive ores for various human needs:- example are to provide - the raw materials - for nuclear power are and ; and in the mining for tin etc. highly materials like monazite and ziroon are stock piled in mining sites and 7 millings are tailing . There are records of wrong use and dispersal of these wastes which have become a major environ­ mental problem worldwide. Even the mining of and other unsuspected minerals add their little percentage of the environmental problems arising from human mining processes. This now brings us to the implications of the human uses of sources of ionising radiation. This is the issue of nuclear safety, and radioactive waste management; an issue which has beclouded man's successful uses of radioactive sources and nuclear energy for growth and development.

Ill Nuclear Safety and Radioactive Waste Management

There is a remarkable record of man's use of ionising radiation and the undisputable progressive contributions it has made to the development, survival and improved activities in all sectors over the past fifty years, However,few topics 6.

have attracted world-wide discussion and critical review as nuclear safety and radioactive waste. In many countries today the future development of is dependent on acceptable solutions for nuclear waste management.

The event at Chernobyl has underscored the international dimensions of nuclear safety; since it gave the world its first real encounter with a severe nuclear accident whose implications went beyond national boundaries. Until this time nuclear power plants worldwide over 3 decades had accumulated nearly 4000 rector-years of good safety and environmental records. However let us identify and outline the known sources of hazards arising from man made uses of the various types of sources of ionising radiation, which are generally classified as radioactive waste management and safe handling of radiation. These deal with

(1) Control, safe use, and disposal of radioactive sources When equipment are not properly used by the handlers of such devices, this can lead to accidents involving over exposure of patients, environment and workers. This happens when unqualified persons operate equipments. At the FRPS here we have had records of cases of over exposure resulting from these sources which we detected after the accidents. This is one reason why monitoring and keeping to working codes are highly essential to users of radiation. Much serious abuses now exist in Nigeria today where X-ray factories spring up out­ side hospitals, being managed by unequalifled nersons. The hazard to the environment and the public is further hightened by the location of these facilities in highly populated areas with inadequate safeguards.

A basic problem is the disposal of radioactive sources. This has constituted a major source of radiation accidents the world over. The accident in Brazil in September 1987, involved the removal of abandoned radiotheraphy equipment with a ceasium-137 radiation source which subsequently was carelessly handled, and caused extensive environ­ mental contamination, human injuries and four deaths. There was one case in Mexico in 1983, another in Morocco in 1984 and a minor case in University College Hospital (UCH) here when the Department of was changing location. These are man made abuses in our use of these sources for human benefits. 7

Table 1: Nuclear power's share of electricity production, 1985-1988

1988 1987 1986 1985 1988 1987 1986 1985

France 69.9 69.8 69.7 64.8 United States 19.5 17.7 16.6 15.5

Belgium 65.5 66.0 67.2 59.8 United Kingdom 19.3 17.5 18.4 19.3

Hungary 48.9 39.2 25.8 23.6 Canada 16.0 15.1 14.7 12.7

Sweden 46.9 45.3 50.3 42.3 USSR 12.6 11.2 10.1 10.3*

Korea, Republic of 46.9 53.3 43.6 23.2 Argentina 11.2 13.4 12.2 11.7 41.0* Taiwan, China 48.5* 43.8* 53.1* Germany, Dem. Rep'. 9.9 9.7* 9.7* 11.2*

Switzerland 37.4 38.3 39.2 39.8 South Africa 7.3 4.5 6.8 4.2

Spain 36.1 31.2 29.4 24.0 5.3 5.2 6.2 6.1

Finland 36.0 36.6 38.4 38.2 Yugoslavia 5.2 5.6 5.4 5.2

Bulgaria 35.6 28.6 30.0 31.6 India 3.0 2.6 2.7 2.2

Germany, Fed. Rep. 34.0 31.3 29.4 31.2 Pakistan 0.6 1.0* 1.8 1.0

Czechoslovakia 26.7 25.9 21.1 14.6 Brazil 0.3 0.5 0.1 1.6

Japan 23.4 29.1 24.7 22.7 Italy 0.0 0.1 4.6 3.8

*IAEA estimates. Expressed as percentage of total lectricity produced 8.

(2) Nuclear plant accidents

We have discussed this when we presented the Chernobyl accident. This type of accident is not of a common occurrence, however the public need to be adequately educated. There are a long year of safety record brought about by improving new safety culture. The technologies are well proven and have established an excellent safety records. This will be obvious when the number of isolated occurence of accidents are compared to number of operating nuclear facilities the world over for many years. This is not to under estimate the probable effects of such singular accidents and failures when they occur across national frontials.

(3) Waste disposal from nuclear plants.

These are spent fuel discharged from nuclear reactors, and some contaminated material used in decomissioned plants, such materials are classified according to degree of radioactivity as (a) low-level waste (LLW), (b) Intermediate level wastes (ILW) and High-level waste (HLW). Most countries with nuclear power programmes develop technology for deep geological disposal facilities for their HLW wastes. While effective treatment and conditioning and disposal technology for LLW and ILW are well developed. When, for some reasons some of these materials are deposited in areas where they have immediate contact with the environment and the ecological systems that they constitute serious danger.

(4) Waste management at mines and mills processing radioactive sources

This is an area where there is the poorest level of management of waste, hence wastes in this category con­ sist the greatest hazards to man-kind who generated them in the course of their activities. The first is the gamma-ray exposure of people who have contact with such areas where high level radioactive wastes are concentrated. In developing countries, those affected are usually unaware of these hazards around them.

There is the intake of radiation from contaminated water and vegetable in these environment. 9.

When materials and tailings from these facilities are used as building materials (e.g. plastering) there is the added inhalation of radon. Radon-222 is a gas and their decay products accounts for elevated lung cancer rates. This has been a national problems in most parts of world including Nigeria (see ref. 5) and references 6-10.

IV. Critical Overview

Of the total amount of industrial wastes generated in the U.K. only 1.1% is radioactive, while 98.9% consists of toxic chemical. Out of the 1.1% radioactive waste, 88.8% of this is low-level radiation, while 11.1% is of intermediate level (ILW), and only 0.1% consists of high level radiation (HLW) see Fig. 1.

Arising from Chernobyl and the three mile Island nuclear accidents the public has held to a hardline position to radiation generating systems. By far the radioactive fuel by-products of commercial power reactors, and to a lesser extent the radioactive sources and equipment used in industry medicine, agriculture, and research are the target of public debate about nuclear energy as developed by man. Unfortunately the wide spread fears and misunderstanding about radiation in our lifes is not supported by facts as shown in Fig. 2 and Table 2. The table show the comparable positions of major industrial disasters, health effects and damages. The nuclear industry has enjoyed highly developed protection technology. The IAEA has shared safety philosophy. This philosophy states that all activities resulting in radiation must be justified in relation to their benefits, and that radiation protection must be optimized to keep radiation doses as low as reasonably achievable, under the constraint of specific limits on individual exposure.

Ionising radiation has become a very important necessity to the development of man, therefore the right attitude should be to continue to strive to make its use safe for mankind. This demands that the safety aspects need to be development along with the use to which we put them so long as their need continue to put their demands on us.

The national attitude here that accident elsewhere may nor have direct relevance to us as a nation is not now supported by facts from recent happenings. Even when we have no nuclear 10

plant, human activities elsewhere will certainly affect us. This has happened many times. The French atomic test in the Sahara, in the 1960s is well known. More serious may be the human errors in the use of the highly versatile tool - as ionising radiation elsewhere. (Example is the release from a nuclear waste transported close to our shore). The only remedy to this type of risk is emergency preparedness. It has helped reduce effects of catastrophies in many exploits of man land. The IAEA is doning a lot to help nations, across national frontials to reduce risks arising from the peaceful use of the atom.

REFERENCES

1. IAEA Bulletin Vol. 31, 1989

2. Report) Weaking Document for 26-29 August, 1989.

3. IAEA News Features 1 & 2, 1988

4. IAEA Newsbriefs Vol. 4, 1989.

5. M.O. Oresegun (Mrs.) Radiological Effects of the Low dose ionising Radiation of the Jos Tin Industry (Ph.D thesis University of Ibadan, Oct. 1986).

6. A Mero:- Physics Today April 1989, p.32. "Earth Air, Radon and Home",

7. I.A. Babalola "Radiation measurement and Assay of Tailing from High Radioactivity in Plateau State. Nig. Jour. Science 18 1984, 98.

8. W. Jacobi - Environmental Radioactivity and man Health Physics 55 1988, 845.

9. M.O. Oresegun and I.A. Babalola - Annual in-door dose burden estimates in dwellings built in Nigeria with radioactive U-Th rich tailings. "Radiation Protection in Nuclear Energy" (IAEA book CN-517) Vol. 2, pages 152. 10. M.O. Oresegun and I.A. Babalola - "Occupational radiation exposure associated with milling of Th-U rich ore in Nigeria Health Physics 58, 1990, 213.