<<

January 1999 Primer

Environmental Programs Office of Toxic Substances

he purpose of this document is to give As a result of the energy crisis of the early T the reader a brief overview of possible seventies, the cost of energy increased by a residential indoor air quality (IAQ) problems factor of almost ten. During that time, the and provide a basic understanding of problem U.S. Government, private industry, and the identification, control methodologies, some commercial sector all developed ways to specific , their sources, potential better design new buildings and homes, as health effects, and indoor air monitoring well as retrofit existing buildings and homes methodology. with better insulation and energy conservation devices. This resulted in energy savings by IAQ in our homes, schools, and office decreasing ventilation, thus reducing or buildings has received increasing attention in eliminating the amount of outside air that the past few years from scientists, engineers, needs to be heated or conditioned. However, regulatory groups, and the public. There is the efforts to conserve energy, along with the growing concern and mounting evidence that increasing use of synthetic building materials, our indoor environment may be responsible contributes to an indoor air environment that for persistent, irritating health effects. is a possible cause of increasing adverse Traditionally, it has been assumed that people health effects. In certain circumstances, were protected from air when reduced ventilation alone has resulted in indoors, particularly near industrialized areas. adverse health effects to occupants due to However, recent research has shown, that this increased levels of indoor air pollutants. is not necessarily true. Current research indicates that our indoor air may be more Several indoor air pollutants have received polluted than outside air, even in special attention. These include industrialized areas. This increased concern is formaldehyde, , radon, and accompanied by the realization that most . Other indoor pollutants that can be people spend 80-90 percent of their time associated with health or irritating effects are indoors and that the young, aged, and health- , nitrogen , household compromised may be at greater risk. and personal care products, microorganisms, and allergens. during cold winter days when air is Although standards for work place exposure high and is low. to many toxic compounds have been established in the and other The first appearance of symptoms are countries, almost no regulatory standards or commonly associated with: guidelines have been established in the U.S. for residential indoor air. Several other Q Moving into a recently purchased home or countries have established residential IAQ new mobile home. standards for several pollutants, particularly Q Recent remodeling. formaldehyde. Our ability to accurately Q Homes with urea-formaldehyde foam assess the health risks associated with insulation. exposure to these compounds is limited. Q Implementing energy conservation There is insufficient data on the number of measures that significantly reduce heat people exposed, the susceptibility of loss and ventilation rates. individuals, the patterns and degree of Q Purchase of new furnishings. exposure, and the actual health effects from Q Installation of new kitchen or bathroom exposure to low levels and of cabinets. pollutants typically found in the residential Q Installation of new carpeting or cleaning environment. of carpeting. Q Use of some recreational vehicles. Problem Identification IAQ related illnesses are usually characterized Office building workers have often been by one or more of the following symptoms: victims of indoor commonly irritation of the eyes, nose and/or ; referred to as "” headache; cough; runny nose; lethargy; and (SBS). SBS events are characterized by a difficulty sleeping. Other less common significant number of building occupants with symptoms reported include dizziness, nausea, specific health complaints. Investigations diarrhea, dry skin, and rash. Symptoms usually reveal several indoor pollutants, more appear unrelated to any identifiable common often than not in extremely low illness. However, because these symptoms concentrations. Usually no one indoor air are common to many different ailments, a can be identified as the likely cause physician, allergist, or dermatologist should of health complaints. It is often thought that be consulted to determine any physical the many pollutants in combination are condition that may account for the symptoms responsible for reported health effects. experienced. The symptoms are often most Investigations have indicated that SBS occurs severe during the winter months. Symptoms most often in buildings where ventilation rates may affect only selected individuals in the are maintained near minimum requirements. home and usually are most severe in family Often improved ventilation alleviates the members who spend the greatest amount of problem. Nonresidential IAQ is discussed in time at home, such as mothers and their young a separate fact sheet distributed by the children. Symptoms become less severe when Washington State Department of Labor and away from the indoor environment in question Industries. Copies can be obtained by calling and often disappear with extended absences (360) 902-5436. (e.g., during vacations). Symptoms will often become less severe or disappear when the home is ventilated by opening windows or

2 Control of Indoor Air energy efficient and non-energy efficient homes, results in a 43 percent increase in Pollutants indoor air contaminants. This increase is also Three general methods are used for dependent upon the contaminant, its source controlling indoor air pollutants: source strength, and rate of emission. removal or modification, ventilation, and air cleaning. For homes with very low ACH and those with certain pollutant producing sources, an active Source Removal/Source Modification mechanical ventilation system may be Source removal and source modification (or necessary. This may be either a system for the substitution) are generally considered before entire home or to control a specific pollutant other alternatives because the pollutant produced from an activity or appliance. For sources and their rates of emission are the instance, it is recommended that gas ranges most important factors in determining the have a mechanical exhaust hood located overall IAQ. Source removal is the most directly above the cooking surface to exhaust desirable since it permanently removes the by-products directly to the pollutant source. In practice, source outside. Because of the additional heating or modification and substitution are the more cooling costs associated with whole house common forms of control. Source ventilation systems, such ventilation is not modification involves measures to reduce recommended without heat recovery. An pollutant emissions, such as restricting efficient, economical mechanical ventilation . Substitution usually involves system for the entire home is an air-to-air heat replacement with a less toxic alternative, such exchanger. These systems, when properly as water based prodiucts versus solvent based. sized and installed, can provide an average of 60-85 percent heat recovery from exhaust air Ventilation and substantially reduce the energy penalty Ventilation can be used to reduce pollutant associated with forced ventilation. In general, concentrations to levels below which no the higher the forced ventilation rate the adverse health effects are experienced. By greater the reduction in pollutants. increasing the ventilation rate in a building, pollutants are rapidly dissipated by providing While ventilation is frequently helpful in less contaminated air from the outside to mix reducing indoor air contaminant with and dilute higher indoor contaminant concentrations, it is more efficient to reduce or levels. This is generally accomplished eliminate pollutants at the source. through non-mechanical means such as infiltration or by opening windows and doors. Air Cleaning Air cleaners operate by mechanical filtration, In older homes and new homes that are not absorption, adsorption, or electrostatic well sealed, the air exchange rate is usually of pollutants. Extended surface between 0.8 and 1.5 pleated filters serve the most effectively and (ACH). Newer, well-constructed houses and will be the most useful over the widest range older, weatherized houses generally have of pollutant types. These filters are available between .5 and 1.0 ACH. Apartments often as stand-alone units, as add-ons, or as in-lines have even lower ACH. One researcher for most home systems. Filter size and reports that each 30 percent reduction in the efficiency vary. Contact your home system ventilation rate, as can be expected between contractor for specific applications.

3 tissue changes, immune system dysfunction Negative ion generators can be effective air and severity and attack rates the cleaners. Negative ion generators emit Department of Health recommends against the negative charged ions which attach to airborne use of generating devices in an , which then attach themselves to occupied space. room surfaces removing them from the air. These particles, however, are potentially Additional information on filter types and subject to resuspension and should be applications can be obtained at the removed with high efficiency particulate air Environmental Protection Agency (EPA) IAQ vacuum cleaners. Although some advertisers' clearinghouse at 1-800-438-4318, or through claims regarding effectiveness and health the American Association at benefits have not been verified, this method is 1-800-LUNG USA. considered moderately effective at reducing particulate levels. Pollutants Electrostatic air precipitators are an effective Following is a brief discussion of common air cleaning method to reduce indoor indoor air pollutants, their sources, potential . These units operate by putting an health effects and acceptable mitigation electrical charge on particulates and then measures. Pollutants included in this removing them from the air by attracting them discussion are: to an oppositely charged plate. These units are available for installation in the of a Q Formaldehyde forced air heating or ventilation system or as Q Asbestos independent units. Electrostatic precipitators Q Radon and negative ion generators may produce Q Tobacco smoke (ETS) ozone, a potential respiratory irritant. Q Combustion by-products However, the amount of ozone produced is Q usually quite small. Q

Q Microorganisms, allergens, and mold Activated carbon and specialty filters with adsorbents are available for the removal of Formaldehyde gaseous contaminants. This method of Formaldehyde (HCHO) is a colorless, filtration can be quite effective; however, flammable gas with a pungent suffocating sizing and maintaining this type of filtration odor. It is the most important aldehyde system can be complicated. The Department produced commercially, and is used in the of Health recommends that you contact your preparation of urea-formaldehyde and heating contractor for help in selecting this phenol-formaldehyde resins. It is also type of filtration system. produced during the combustion of organic materials and is a component of smoke. Ozone generating devices have been much touted as the final cure for all indoor air Health Effects problems. Testing has been done which Health effects associated with exposure to indicates that these devices can and do exceed HCHO fall into several categories. These the work place standard of 0.1 parts per include: irritant effects, sensitization, and million (PPM). Since ozone is a potent carcinogenicity. HCHO is intensely irritating irritant and toxic material implicated in lung to the mucous membranes, which includes

4 the eyes and . Common The odor threshold ranges from 0.05 PPM to symptoms from exposure to HCHO include: 1 PPM. At concentrations of 0.05 to 0.5 PPM burning eyes, nose, and throat; headache; and HCHO produces a definable sensation of eye nausea. HCHO has the potential to sensitize irritation. In occupational studies, reports of exposed individuals, which can involve both eye tearing, prickling, stinging, and burning asthma symptoms and skin reactions. Some are reported at levels from 0.13 to 2.7 PPM. people exposed to HCHO will develop Airway irritation has been reported as low as asthma symptoms. These symptoms include 0.1 PPM, but more commonly occurs in wheezing and chest congestion. Urticaria (a ranges of 1 to 11 PPM. Symptoms range skin condition marked by intensely itching from the feeling of a dry throat, tingling of wheals usually caused by an allergic reaction) the nose, to a sore throat. However, airway has been reported following inhalation of irritation (at concentrations of 5-30 PPM) is HCHO fumes. HCHO can be considered a characterized by cough, chest tightness, and sensitizing agent. Documentation of this wheezing. Chronic industrial exposure to effect has been seen in dialysis patients, as concentrations ranging from 0.5 to 8.9 PPM well as persons chronically exposed to low produce changes in the nasal and pharyngeal levels in mobile homes. HCHO has been mucosa, and complaints of throat irritation, designated as a probable human , diminished sense of smell, and dryness of the and has also been designated as a workplace throat. HCHO has been associated with both carcinogen by the National Institute for the development of asthma and the initiation Occupational Safety and Health (NIOSH). of asthma attacks. High levels (50-100 PPM) have been associated with swelling of the U.S. Occupational Safety and Health lung and movement of fluid into the lung, as Administration and Washington State well as pneumonia. Exposures to levels Department of Labor and Industries greater than 100 PPM can be fatal. workplace regulations call for exposures which do not exceed 0.75 PPM as an eight Sources hour time weighted average (TWA), with a The major sources in residential settings are 0.5 PPM action level, and a 2 PPM short-term building materials. These products may exposure limit for 15 minutes. NIOSH contain phenol, urea, thiourea, or melamine recommends a 0.016 PPM eight hour TWA resins which contain HCHO. HCHO has also and a 0.1 PPM 15 minute ceiling. The been used in the paper, photographic, and American Council of Governmental clothing industries. It is used in the finishing Industrial Hygienist recommend a ceiling of of all permanent press material, and can be 0.3 PPM. found in the glues used in furniture No residential standard exists in Washington construction, or carpet and vinyl attachments. State. The American Society of Heating, , and Urea-formaldehyde resin containing products Engineers recommends a maximum are the most common HCHO source in the continuous indoor air concentration of 0.1 home. This formulation is approved for PPM. Other states and several foreign interior grade materials such as plywood, countries have guidelines or standards for hardwood cabinetry, and wall paneling. residential indoor air exposures which range Urea-formaldehyde resins release trapped from 0.1 to 0.5 PPM. free HCHO, as well as HCHO resulting from chemical degradation. Degradation of HCHO resins can occur when these materials become

5 damp from exposure to high relative asbestos accounts for approximately 95 , or if the HCHO materials are percent of all asbestos used and is anticipated saturated with water during flooding, or when to be less pathogenic than the amphibole type leaks occur. The release of HCHO occurs asbestos products. when the catalysts involved in the resin formulation are reactivated. Levels of out- Sources gassing can also increase with increasing Asbestos-containing materials may be present temperatures and relative humidity. in many household products manufactured before 1977, as well as in many areas in and Control Methods around the home. Some of the more common The prevention of problems associated with locations are old pipe and insulation, exposure to HCHO are best treated by source vinyl floor tiles and vinyl sheet flooring, control. The selection of HCHO free or low- patching compounds and textured paints, emitting products such as exterior grade brake and clutch pads, roofing materials, plywood which use phenol HCHO resins for home siding, some 1930-1950 wall and indoor use is the ideal starting point. ceiling insulations, some decorative ceiling Alternatives to source control include: materials, and other items requiring the filtration, sealants, and fumigation treatments. characteristics of asbestos. Filtration can be achieved using selected adsorbents. Sealants involve coating the Health Effects materials in question with two or three coats Asbestos exposure has been shown to cause of nitro-cellulose varnish, or water based of the lung; a rare cancer of the chest polyurethane. Three coats of these materials and abdominal lining called mesothelioma; can reduce out-gassing by as much as 90 and of the esophagus, stomach, colon, percent. Professional carrier gas treatment and other organs. It can also cause a with will also minimize HCHO out- noncancerous chronic and debilitating lung gassing. disease called asbestosis. Asbestosis is related to lengthy exposure to high levels of asbestos Testing for HCHO can be accomplished with fibers as was common in some industrial passive monitors, real time active monitors, environments during the 1920s to the 1940s. or colorimetric sorbent tubes. Passive Asbestosis is not considered a significant monitors can be purchased through industrial outcome from incidental nonoccupational hygiene suppliers or through independent exposure. The amount of exposure necessary contractors who manufacture their own to cause disease is unknown and is probably monitors. For listings in your area, refer to different for different population subgroups. your telephone book under analytical Asbestos-related diseases generally do not laboratories or environmental services. appear for 15-35 years after first exposure. This length of time between first exposure and Asbestos onset of disease appears to be related to the Asbestos is the generic name for several amount and duration of exposure. However, it fibrous minerals. The three main types are is believed that any exposure to asbestos chrysotile (white), crocidolite (blue), and involves some health risk. No safe level of amosite (brown). Asbestos' characteristics of exposure has been established. flexibility, strength, incombustibility, and durability resulted in its widespread use Asbestos and smoking combined between the 1920s and mid 1970s. Chrysotile significantly increase the potential for lung

6 cancer. Studies have shown asbestos workers who smoke have a risk of eight Homeowners choosing to do their own times greater than smokers in the general removal must first notify their local air population. This same group has a lung pollution control authority. They may also be cancer risk 92 times greater than unexposed required to notify their local health department nonsmokers. and other local government agencies. Information regarding proper removal The presence of asbestos in the home alone practices, protective equipment, and disposal does not necessarily mean there is an exposure can be obtained through local health problem. Asbestos is hazardous if inhaled and departments, local air pollution control this usually occurs only when asbestos- authorities, and the Department of Labor and containing materials have been damaged and Industries. there is a release of asbestos fibers. Of greatest concern are asbestos products that are Radon friable (this means easily crumbled, Radon gas is a chemically inert, odorless, pulverized, or powdered by hand). Unless the colorless, and tasteless naturally-occurring material is crumbling, needs repair, or must be radioactive element found in soils and rocks removed, it is recommended that it not be that make up the earth's crust. It comes from disturbed. Improper removal and handling the normal decay of radium. Because it is a can release high levels of fibers into the air gas, it can easily move through soil and water that then become a continual source of and enter the . Radon gas has a exposure. half-life approximating four days, after which it decays into four daughter products. These Control Methods decay products are not inert and often Asbestos control methods generally include attach themselves to airborne particulates source removal or source modification. Small which may then enter the . These minor repairs can often be taken care of by particles with attached radon daughters may duct tape or other commercial products which become lodged in the lungs where the radon seal the damaged area. Heat resistant paints daughters undergo rapid decay, emitting and sealers are also sometimes suitable for radiation that damages lung tissue. small repairs. These products are often available through commercial paint and safety Sources supply outlets. In the Northwest, the major source of radon gas in the home is the soil beneath and Removal should be done only when surrounding the residence. Common entry necessary. Although current law permits a routes are through cracks in concrete slabs; homeowner to perform their own removal cracks between poured concrete slabs; and work, it is recommended that removal work blocks, pores and cracks in concrete blocks, be done only by contractors with highly- slab footing joints, and mortar joints; loose trained workers who are required to be fitting pipes; sump pits; and floor drains. certified by the Washington State Department Houses built on foundations with a ventilated of Labor and Industries. These workers are crawl space should have few problems. knowledgeable about the permits that must be Houses with basements and those built obtained, safe removal practices, necessary directly on or in the ground have a higher protective equipment, and proper disposal potential for problems. methods.

7 Concentrations Q Improve basement or crawl space Concentrations of radon and its daughter ventilation by increasing vent number, products are usually measured in pico-Curies size, and/or using fans. per liter (pCi/l). The current action level (the level at which you should consider Q Increase the air pressure in ground floor or modifications) is 4 pCi/l. The Bonneville basement area to reduce radon entry. Power Administration, in cooperation with the WSU cooperative extension service and local Q Ventilate the area under the basement or utilities, has measured radon in thousands of slab (sub-slab depressurization) to reduce homes in Washington State. To date, levels the amount of radon available to enter the have ranged from less than 1 to 103 pCi/l. home. Most of the higher levels have been found in Northeastern Washington, due to the naturally Additional information and brochures occurring radium in the soil and rock. regarding radon, its , measurement, Western Washington does not appear to have and control techniques can be obtained by significant radon levels, although exceptions calling 1-800-SOS-RADON. have been found. Nationally, the average radon concentration is approximately 1 pCi/1. Tobacco Smoke The only way to know about your house is Indoor tobacco smoke is a major contributor to test. to airborne contaminants in the home and other indoor environments. Over 4,000 Health Effects chemical compounds, of which 40 are known Like other radioactive materials, radon can or suspected , have been identified cause cancer. Much of the knowledge of the in tobacco smoke. Some of the more health significance of radon and its progeny is important pollutants are carbon monoxide, based on the analysis of the effects of high , hydrogen cyanide, formaldehyde, exposures on underground miners. Based on nitrous oxides, pyrene, , , several studies and current knowledge, the and numerous carcinogenic polycyclic National Academy of Sciences believe that aromatic hydrocarbons. Environmental radon and its progeny are harmful at all tobacco smoke (ETS), or the smoke that exposure levels, and increased lengths of comes directly from burning tobacco, has up exposure and higher doses will increase the to 50 times the concentration of some risk of cancer. EPA has estimated that as carcinogenic compounds as does mainstream many as 10 percent of lung cancer in or exhaled smoke, because of the lower the U.S. may result from exposure to indoor combustion temperature. ETS contributes radon. approximately 90 percent of the total products of combustion from a cigarette. Control Methods Usually, radon reduction is fairly simple and Tobacco smoke is also the major source of inexpensive. Methods, in order of increased respirable suspended particulates (RSP). complexity and expense, are: Wood smoke, unvented gas appliances, and heaters also contribute to indoor Q Seal radon entry points with appropriate RSP concentrations. Studies have shown that caulking material and cover sumps and particulate concentrations in public buildings drains. and homes where smoking is permitted often

8 exceed EPA's 24-hour outdoor air quality recent study has reported that nonsmoking standard. wives of husbands who smoke have three times the risk of heart attack than nonsmoking Health Effects women married to nonsmokers. ETS may The health effects related to ETS exposure very likely be the most harmful indoor air have only recently been investigated. The pollutant. acute effects of involuntary smoking often depend on the individual being exposed. Control Methods Principal acute effects can include: irritation Only the prohibition of smoking assures a of the eyes, nose and throat; coughing; smoke-free environment. Other control headache; nausea; increased blood pressure; methods generally consist of increasing increased heart rate; and elevated ventilation, use of air cleaning devices, or the levels. restriction of smoking. For air cleaning also affects several vulnerable subgroups of devices to be effective, they must be large the population more than others. Many enough to circulate large volumes of air. Air people with pre-existing health conditions, cleaners, such as electrostatic precipitators, particularly those with asthma and other are only partially effective in that they remove respiratory diseases, are often severely only particulates and not the gases associated affected by exposure to ETS. with tobacco combustion.

Many studies have shown adverse health Indoor Combustion By-Products effects to children of smokers. These studies Indoor combustion of fuels can be a source of have shown an association with increased increased concentrations of gases and respiratory illness and decreased pulmonary particulates. The major combustion by- function. Infants and children under two products of concern are carbon monoxide years old seem particularly susceptible. (CO), nitrous oxides (NOx), and RSP. Other Infants exposed to passive smoke also have by-products may include sulfur dioxide, triple the rate of sudden infant syndrome formaldehyde, carbon dioxide, hydrogen compared to nonexposed infants. In children cyanide, and organic vapors. Common of smoking parents, other effects also reported sources of indoor combustion by-products are include decreased attention and work unvented kerosene heaters, wood , gas capacity, increased developmental disability stoves, and tobacco smoke. and respiratory problems, and decreased school attendance. Carbon Monoxide Cabon Monoxide (CO) is a colorless, It has long been known that smoking odorless gas produced through incomplete increases the risks of lung, laryngeal, oral, combustion. CO is a poison that binds with esophageal, other organ cancers, and heart hemoglobin, the oxygen-carrying molecule disease. The association between ETS in human blood. Because CO’s affinity to exposure and cancer is clear. Increasing bind with hemoglobin is 250 times greater evidence indicates a high risk of lung cancer than oxygen, low airborne concentrations and heart disease for persons exposed to ETS. and long exposure times can result in Several studies of nonsmoking wives of substantial carboxyhemoglobin (COHb) smoking husbands have found a statistically concentrations in the blood. COHb is CO significant association between passive smoke bound to hemoglobin. As COHb levels exposure at home and risk of lung cancer. A increase, less hemoglobin is available for the

9 of oxygen. This lack of oxygen- Environmental Pollution carrying capability, which is indicated by The National Ambient (outdoor) Air Quality the increase in COHb, results in the Standard for CO is 9 PPM averaged over an symptoms we associate with CO poisoning. eight hour period, or 35 PPM averaged over one hour. These standards are based on Health Impacts preventing adverse effects in individuals The acute health effects of CO exposure are with cardiac or vascular disease and in well established. Mild exposure symptoms exercising humans. Seattle, Spokane, may include headache, dizziness, decreased Yakima, and parts of Pierce and Thurston vigilance, decreased hand-eye coordination, Counties may exceed these values during weakness, confusion, disorientation, heavy traffic periods and when inversions lethargy, chest pain (in cardiac patients), occur. Inversions occur when cold stable air nausea, and visual disturbances. Greater or layers form above warmer air. This traps prolonged exposure can cause pollutants beneath the stable air layer. This unconsciousness and death. The severity of can result in significant pollutant level symptoms depends on the concentration of increases, including CO. As outdoor levels CO, length of exposure, and degree of increase due to peak traffic times, or because physical activity, as well as the state of of an inversion, indoor levels will rise health of the exposed individuals. People proportionately. If indoor sources of CO who are exposed to high CO concentrations exist, indoor levels will be higher than those for long periods of time during strenuous outside. Avoid strenuous physical activity activity will reach the highest COHb levels. during peak traffic times, in high volume traffic areas, and during inversions. Even low levels of CO can present a health risk to susceptible individuals, such as Appliances persons with heart disease, sickle cell Indoor wood stoves, gas ranges, gas hot disease, and anemia. Age and general health water heaters, gas and oil heaters, , may also affect susceptibility to CO. and kerosene space heaters can all be Exposure to low levels of CO may harm the sources of CO. Heating season is a time of developing fetus. particular concern with regard to CO exposure. Gas and oil heaters that have not Angina pectoris is chest pain associated with been used during the warm summer months impaired oxygen flow to the heart and may should not be expected to perform occur at COHb levels between 2.5 and 4.9 efficiently without the benefit of service. It percent in cardiac patients. In healthy is imperative that furnaces be cleaned and individuals, decreased vigilance, confusion serviced following the manufacturers and disorientation, behavioral, and central instructions. Winter is also the time of year nervous system effects occur at COHb levels when people use space heaters. It is very between 4 and 6 percent. Remember that important to use the correct grade of as symptoms of CO poisoning increase, kerosene (1-K or manufacturers you may become confused and less suggested grade). Use of the incorrect capable of making decisions that could grade of fuel will result in an increased save your life. production of CO.

Sources: Flame color is a good way to check the combustion of a fuel burning appliance. The

10 flame should burn with a bright blue color. percent. Nonsmokers have COHb levels of A yellow flame signals poor combustion and 0.5 percent, whereas nonsmokers exposed to may indicate a problem with the or secondary tobacco smoke have been shown burner. Ideally, combustion air for fuel to have COHb levels in the two to three burning appliances should not be drawn percent range. from inside the home. Some newer furnaces draw air from outside the home and this Automobiles, Campers, RVs, and Boats alleviates the possibility of back drafting. CO produced from cars left running in Fuel burning appliances which do not draw closed garages can accumulate and enter the combustion air from outside the home are home. Traveling in truck canopies and subject to back drafting, which occurs when campers presents an especially high risk for flue gases, including CO, are drawn back children. The University of Washington and through the flue into the living space in the Virginia Mason have reported deaths and home. This occurs because of an air loss of consciousness and other signs of CO pressure drop in the home resulting from exposure in children in Washington State high wind conditions or in tight homes when who were affected while riding in covered local exhaust fans are used without adequate truck beds. CO will accumulate in this make-up air. Back drafting may also be space because the shape of the truck caused by blocked or partially blocked . produces turbulence, which can lower the air Flues should be inspected regularly. If you pressure in the truck bed, drawing exhaust suspect back drafting contact your into the covered area. No one should ride furnace service representative or your inside covered truck beds. Every year there fuel supplier. are deaths associated with CO poisoning. The majority of these deaths are associated Power outages are a time of higher risk. with motor vehicle exhaust (CO) leaking During power outages, people often resort to into cars, campers, and motor homes. Be the use of kerosene space heaters, fire sure to provide adequate ventilation. It is places, gas ranges, and even barbecues to important that cars and trucks have a heat homes. Do not use barbecues or gas functional “tight” exhaust system. ranges for a heat source. If unvented fuel burning space heaters are used for warmth, Prevention be sure that windows are opened slightly to To prevent or reduce exposure to CO, be provide fresh air into the living areas. sure to provide ventilation during fuel Additionally, gas ranges should not be used burning appliance use, do not run cars in without local exhaust, such as exhaust fans closed garages, and maintain your car’s or vented hoods that are exhausted to the exhaust system. If your home has fuel outside. burning appliances you may want to obtain a CO alarm. These units are very similar to Combustion smoke alarms and warn occupants when CO Tobacco smoke, including second hand levels become unsafe. There are also smoke, is a large source of CO in homes several monitors available that change color with smokers. Smokers have higher COHb during CO exposure. These are not very values than nonsmokers and exposure to precise in indicating CO levels. The gas secondary tobacco smoke results in an company will test your home for CO if you increase in COHb values. Smokers are a customer and suspect a gas leak, smell generally have COHb values of five to six combustion fumes, or describe symptoms

11 associated with CO exposure. There are of minor respiratory illness and reduced also independent testing labs that can test respiratory function. your home; however, they do charge a fee. If you suspect a problem with a gas Respirable Suspended Particulates appliance, contact your gas supplier. Respirable suspended particulates (RSP) are particles, organic and inorganic, that are If you think you have a problem, act suspended in the air and are small enough to immediately: leave, call from outside the be inhaled into the lungs. RSPs are also often home, and do not return to the home until referred to as PM2.5 or as PM10s, particulate the problem has been resolved. Severe 2.5 microns or 10 microns in size or CO poisoning symptoms require less. emergency medical treatment. Sources The major source is tobacco smoke. There is Nitrogen Oxides increasing evidence that wood smoke is also a Nitrogen oxides are highly toxic and irritating major contributor during the heating season. gases with a pungent odor. Unvented gas appliances and kerosene heaters also produce RSP. Sources The primary source for indoor nitrous oxides Concentrations are gas burning appliances. There are no indoor standards for RSP. EPA has, however, established an annual average Concentrations outdoor standard of 15 ug/m3 (micrograms Indoor nitrogen dioxide (NO2) concentrations per cubic meter), and a maximum 24-hour range between .03-.5 PPM with peak standard of 65 ug/m3 for PM 2.5’s. PM 10 concentrations of .7 PPM having been standards are set at 50 ug/m3 for an annual measured in kitchens and other rooms of average outdoor, and a maximum 24 hour homes during conventional gas cooking and standard of 150 ug/m3 for respirable use of unvented gas appliances. EPA's particulates. As previously mentioned, these standard for outdoor air is 0.05 PPM. standards are often exceeded in indoor Generally, indoor concentrations do not environments where smoking is permitted. exceed these standards, except during and shortly after use of unvented gas appliances. Health Effects RSPs are comprised of many different Health Effects compounds. Radon and benzo-a-pyrene, Inhalation of nitrogen dioxide can induce suspected carcinogenic agents, are transported effects similar to CO. Nitrogen oxides react by RSPs into the lungs. Gases or other with the blood's hemoglobin, decreasing the substances may also be carried by RSPs into blood's oxygen-carrying capabilities and the lungs. Respiratory illness, especially increasing cardiovascular stress. Nitrogen chronic illnesses like , emphysema, oxides can also produce temporary and long- and asthma may be linked to, or aggravated term damage to bronchial airway and other by, exposure to RSPs. lung tissues. Several studies, although not conclusive, have shown that children living in Control Methods homes with gas appliances have elevated rates Control approaches for these pollutants center on improving combustion efficiency of

12 various household equipment such as gas enclosed spaces have resulted in acute and ranges, kerosene heaters, wood stoves, or chronic disorders and even death. , along with adequate ventilation and substitution. Control Methods The primary means of control have been RSPs, tobacco smoke, allergens and substitution and increased ventilation. microorganisms are often considered similarly Increased awareness and concern by the with respect to control methods (see sections public has resulted in manufacturers on tobacco smoke on page 8 and substituting less toxic chemicals in many microorganisms and allergens on page 15). consumer products and prompting them to make more products available in non- Household Chemicals form. In addition, consumers are being more selective in the type of products they choose Sources and how they are used. Many consumer products emit gaseous or particulate contaminants during their use or in Pesticides storage. Consumer products, such as cleaners, waxes, paints, adhesives, detergents, paint Sources strippers, dry cleaning agents, deodorizers, Pesticides are chemical or biological pesticides, solvents, and many home craft substances used to destroy, prevent, or control products can be sources of both organic and insects, vegetation, rodents, and other pest inorganic contaminants. , which are organisms. A 1976-77 EPA revealed widely used to package products such as that over 90 percent of U.S. households used cleaners, waxes, pesticides, polishes, paints, pesticides and that over 80 percent of the and adhesives, can be particularly important households used them indoors. Twelve of the because they dispense the contents in a form most commonly used pesticides were that makes them readily available for direct insecticides. Some of the most widely used inhalation. Each use of these products can pesticides are the disinfectants (anti- release substantial quantities of particulates, microbials). The study showed that over 90 solvents, and propellant. Additional sources percent of households use disinfectants in for indoor volatile chemicals include , either the or aerosol forms. textiles, building materials, and carpets which may release small amounts over long periods Use of pesticides in dwellings may be by the of time. occupant or building maintenance staff who purchase an "off-the-shelf" product, or by a Health Effects commercial pest control applicator. On The wide variety of chemicals used in occasion, the source of indoors may consumer products and materials precludes a result from drift of the chemical from an discussion of specific household chemicals outside application through open windows and their potential adverse health effects. The and doors. In addition to the direct health risks associated with long-term application of pesticide in to household air, exposure to the low levels commonly there are other sources which continually emit experienced in the indoor environment has not vapors into the living space. For example, the been investigated adequately. Willful abuse intrusion of chemical vapors from insecticides of aerosols and careless use of solvents in through the floors and walls from application to the crawl space and foundation of the

13 dwelling, evaporation of residues from crack day inside the home, nearly three times the and crevice treatments to the interior of the 8-hour shift. It has been recommended that a building, and vapors from moth repellents and healthy adult living at home should not be room deodorizers. In many areas pre- or post- exposed to more than one-fourth the work construction treatment for carpenter ants or place PEL. In addition, an infant, elderly termite protection is undertaken. Some of person, or someone who is ill may be more these pesticides may persist in the home susceptible to the effects of small amounts. environment for many months or years after application. Chlordane (an insecticide of Control methods choice for termite and carpenter ant control) Corrective measures other than general has been found to persist for over 20 years improvement of IAQ is usually not warranted. after treatment. Pesticides considered Additional preventive measures are nonpersistent last much longer indoors, where expensive and their success rate in lowering they are protected from sunlight, water, and air concentrations is questionable. There are other factors which hasten their degradation. several ways to minimize exposure to indoor airborne pesticide levels: Health Effects The large variety of pesticides used in and Q Increase the circulation of clean air in the around dwellings prohibits a discussion of house. When weather permits, specific symptoms and potential adverse periodically open windows and doors, and health effects associated with each pesticide. use fans to mix the air. In crawl spaces, The health risks associated with long-term clear or add vents and install a to inhalation exposure to low levels commonly constantly vent crawlspace air to the experienced in the indoor environment has not outside. been adequately investigated. In addition to Q Seal areas that directly contact treated soil, pesticides themselves, approximately 1,200 using grout, caulk, or sealant. Fill cracks inert ingredients are currently registered for in basement, ground floors, and walls, and use in pesticide formulations. These include openings around pipes, drains, and sumps. solvents, propellants, emulsifiers, and adjuvants. Adequate toxicological data is Q Install a system that supplies outside air to available for only about one-third of these appliances like clothes dryers and furnaces additives. The EPA has serious concerns that now draw air from inside the house. about potential health effects associated with Appliances that use indoor air may 120 of these additives. Proper interpretation actually help draw vapors from the soil of airborne pesticides values is very into the house through walls, floors, and important. While there are occupational basements. airborne pesticide permissible exposures levels (PEL), based on five 8-hour working Q Check the condition of ducts in the days per week, these have limited value in the crawlspace of the basement. Use duct home situation. If residential values exceed tape to seal openings and joints. the PEL, they would also be excessive for the home. However, if airborne pesticide values Additional Pesticide Assistance Information are below the PEL, for a given chemical, this Application of a pesticide by a commercial does not mean they are safe for residential applicator or a private individual contrary to occupants. Full-time homemakers and small label instructions is termed a misapplication children may spend in excess of 21 hours per and is a violation of both state and federal

14 regulations. Enforcement of pesticide Control Methods regulations and investigation of pesticide Many illnesses, including respiratory misapplications are under the jurisdiction of illnesses, appear to be transmitted primarily the Washington State Department of from person-to-person. Overcrowding, Agriculture (WSDA). If you believe that a reduced ventilation, and increased use of misapplication has been made and you wish to untreated recirculated air have a potential to file a complaint, contact WSDA at increase concentrations of microorganisms (360) 902-2040 in Olympia, and allergens. There is limited data or (509) 576-3064 in Yakima. establishing a correlation between acute and ventilation rates. If you have questions regarding health effects, More common control methods for preventing you can contact your local health department transmission of illnesses include less crowded or this office (360) 2336-3360 or 1-888-586- living conditions, isolation of infected 9427. If you have symptoms which you individuals, and vaccination. believe are associated with a recent application, you should contact your physician Temperature and humidity conditions are or regional poison control center for advice. important for many microorganisms, allergens, and molds. Molds need available Microorganisms, Allergens, and Mold water to grow. Studies have shown a relationship between respiratory infections Sources and low or high relative humidity. Studies A large variety of biological material is have also shown that the survival or present in the indoor environment. Sources infectivity of microorganisms and allergic include virtually everything indoors, but mite and fungal populations is directly mainly people, animals, plants, and insects. dependent on relative humidity. These studies suggest that maintaining a relative humidity Health Effects between 40 to 60 percent indoors would Many different organisms are known to cause minimize adverse health effects from infection and many more can produce allergic microorganisms and allergens by reducing responses in man. The inhalation of their indoor populations. Many of the biological aerosols from people and animals is microorganisms and allergens are also the primary means of contracting respiratory dependent on suitable temperatures to survive. infections, although air-cooling equipment, , cool- vaporizers, and For the sensitive individual with allergies, nebulizers can also incubate and distribute control methods (air-cleaning devices) bacterial aerosols indoors and could be a are recommended to reduce the concentration source of infection. of potential allergens in the home. However, it is important to realize the efficiency and According to the National Health Survey, effectiveness of these devices differ and that respiratory illnesses are responsible for more they should not be used without other than half of all acute conditions. Pollen, environmental control methods. Recent molds, dust mites, animal dander, algae, and reports have questioned the ability of these insect parts are known allergens. The effect units to significantly reduce symptoms of these antigens in the asthmatic and allergic because allergens of most concern, such as individual has been well-defined. animal allergens, mite fecal pellets, and pollens quickly settle to the floor and,

15 therefore, are not removed by air cleaning. that collects the pollutant by diffusion or Some studies have indicated that air permeation to absorbent media. Other conditioning alone is as effective as methods are laboratory analyses of bulk specialized air cleaning devices. This is most samples for asbestos and radon monitoring likely related to the control of relative devices. humidity and the resulting control of microbial, mite, and fungal populations. Active monitoring systems are used by The first step to controlling mold growth laboratories and environmental services. involves stopping all available water sources. These methods are generally considered to Quick drying of wet materials is next and more accurately measure pollutant should be accomplished within 24 hours. The concentrations. These services can be located smell of mold and visible mold growth are by looking under Laboratories-Analytical, in indications of a problem and testing is not the Yellow Pages of the telephone book. The generally recommended. The last step is costs for these services vary from company- clean-up with a five percent bleach . to-company and depend on the type of service Keep in mind that permeable objects like required. mattresses and furniture may not be cleanable. In this instance, disposal of the contaminated Passive monitors for chemical pollutants are objects may be the only viable option. available from several different sources such as analytical laboratories, environmental services, safety and supply companies, and the manufacturer. Recent developments in Monitoring for Indoor Air passive monitors for formaldehyde have Pollutants improved their accuracy and reliability. Tools for monitoring and measuring indoor air Passive monitors are considered an pollutants are in a state of rapid evolution. Our inexpensive alternate to active monitoring capabilities to measure minute quantities of methods, and are routinely recommended for chemicals have evolved faster than our ability residential screening. to identify the health implications associated Monitoring devices and/or methods for with low levels commonly identified in the common measurable pollutants follow: indoor environment. Currently, there are no recognized validated standard methods or Formaldehyde procedures for monitoring and analyzing Q Active monitoring–consult with private residential and nonoccupational indoor air. analytical laboratory or environmental Generally, methods have either been research service. or standard methods that were developed for other uses, usually occupational. Increasing Q Passive monitors–available from concern and demand has resulted in rapid environmental services and some safety development and marketing of devices for and supply companies. Monitors are measuring residential indoor air pollutants, placed in the home and then returned for particularly formaldehyde and radon. analysis. Prices vary.

Radon The most common methods used to measure Radon-measuring devices are lightweight indoor air pollutants are use of an air pump to monitors that vary in size from the size actively move air through a media to collect of a wristwatch to a tuna fish can. They are the pollutant of concern; or, a passive method installed in the home and then returned to a

16 laboratory for analysis. Sampling times vary Interpretation of results is often very difficult from one month to one year. because of the wide susceptibility of individuals. In many instances where indoor Asbestos air related illnesses have been suspected, a Asbestos cannot be identified by unaided wide range of different pollutants have been visual inspection. However, it may be identified with no one pollutant identifiable as identified by chemical or microscopic a causative agent. In many instances, it may methods. Bulk samples for asbestos analyses be a combination of two or more pollutants should be submitted to an analytical that produce the adverse health effects. laboratory with asbestos analysis capabilities. Remember, there are no universally accepted IAQ standards for the residential and These laboratories are listed in the Yellow nonoccupational environment. Lastly, it must Pages of the telephone book under be realized that a host of variables can Laboratories-Analytical. influence single readings and values may not necessarily reflect average values. Local Nitrous Oxides health agencies can often be of assistance in Passive monitors are also available for nitrous interpreting results. oxides. These monitors have been developed for industrial environment monitoring and usually are not sensitive enough to measure low levels found in the home. They may be useful for confirming higher levels of these pollutants. The monitors are available Bibliography through safety and supply companies and Indoor Pollutants, National Research some analytical laboratories. Council, National Academy Press, Washington, D.C., 1981. Pesticides Measurement of airborne pesticide levels Indoor Air Pollution and Housing basically consists of three elements: Technology, Mortgage and Housing Corporation, Ottawa, Canada, 1983. 1. Collection of the sample. 2. Chemical analysis of the sample. Indoor Air and Human Health, edited by 3. Interpretation of the values found. Richard B. Gammage, Stephan V. Kaye; Technical Editor Vivian A. Jacobs; Lewis Measurement of airborne pesticide levels in a Publishers, Inc., Chelsea, MI, 1985. home is not something that the average homeowner can do for himself. In most cases, Lebowitz, Michael D. "Health Effects of it takes expensive equipment which must be Indoor Pollutants", Annual Review Public precisely calibrated. A person must rely on Health, 1983. 4:203-221. private consulting and analytical laboratories. Measurement and analysis of samples is by Fisk, W.J., et al. Indoor Air Quality Control no means inexpensive. Unless you have a Techniques, Noyes Data Corporation, Park recommendation from someone, the best way Ridge, NJ, 1987. to locate a firm is by looking in the Yellow Pages of the telephone book under Meyer, Beat. Indoor Air Quality, Addison- Laboratories-Analytical. Wesley Publications Co., Inc., Reading, MA, 1983.

Spengler, John D. and Sexton, Ken. "Indoor Interpreting Results Air Pollution: A Public Health Perspective",

17 Science, 1 July 1983, Vol. 221, No. 4605, pg. 9-17.

Turiel, Isaac. Indoor Air Quality and Human Health, Stanford University Press, Stanford, CA, 1985.

Wadden, Richard A. and Scheff, Peter A. Indoor Air Pollution, John Wiley and Sons, New York, NY, 1983.

Walsh, Phillip J., Dudney, Charles S. and Copenhaver, Emily D. Indoor Air Quality, CRC Press, Boca Raton, Florida, 1984.

Guidance for Controlling Asbestos- Containing Materials in Buildings, United States Environmental Protection Agency, Washington, D.C., 1985.

Asbestos in the Home, U.S. Consumer Product Safety Commission and U.S. Environmental Protection Agency, Washington, D.C., 1982.

Need More Information? Please contact: • Local Health Agencies • Environmental Protection Agency (800) 438-4318 • Washington State Department of Ecology Air Programs (360) 407-6800 • Department of Labor & Industries Non-Residential Problems (800) 423-7233 • Department of Health Office of Toxic Substances Residential Problems (360) 236-3360 or 1-888-586-9427.

18