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Air Pollution Kathleen McNiff Mortimer, MPH and Ruth A. Etzel, MD, PhD
Learning Objectives After completing this module, faculty will be able to teach students and residents to:
General Principles of Air Pollution Introduction Children are not little adults. This statement is particularly true when it comes to assessing the impact of environmental hazards on children's health. Children are experiencing rapid lung development and compared to adults, have different breathing zones, a greater respiration rate, and engage in more physical activity. These factors mean that children may be even more susceptible than adults to the adverse effects of airborne toxicants. Whether children experience health problems from air pollution depends on predisposing health factors (such as asthma), the duration and intensity of the exposure, and the child's access to medical attention. Effects may be immediate or may surface years after exposure. The following sections outline sources of the major components of outdoor and in-door air pollutants and the symptoms the pollutants may provoke. Case studies and recommendations are provided for inclusion into your curriculum; doing so will increase your students' awareness of hazards from everyday exposures to environmental toxins. Requiring students to present current case studies and literature reviews will reinforce the importance of examining the patient's environment and its effect on health and well-being. Your students can refer to the "Recommendations for Parents" (included in the appendix) to explore prevention options with parents. Outdoor Air Sources of outdoor pollution include transportation, industry, electrical power generation, refuse disposal, and residential wood combustion, as well as natural sources such as wildfires. The major outdoor air pollutants are carbon monoxide, sulfur oxides, hydrocarbons, ozone, particulate matter, and nitrogen oxides. An extensive body of literature suggests that outdoor air pollution contributes to respiratory and cardiovascular mortality, increases in asthma exacerbations and respiratory symptoms, and eye and throat irritation. Exposure to other agents such as environmental tobacco smoke or allergens may exacerbate the effect of outdoor air pollution. Among children, the health effects from exposure to outdoor air pollution are primarily respiratory. Chronic exposure has been associated with increased bronchitis and decreased pulmonary function in children. Other effects include the increases in school absenteeism and hospital admissions that coincide with acute episodes of air pollution as measured by increases in ozone (O 3 ), total suspended particles (TSP), sulfur dioxide (SO 2 ), sulfuric acid (H 2 SO 4 ), fine particulate matter, and aerosol acidity (H + ). It is important to note that adverse health effects have been found at levels below Environmental Protection Agency (EPA) air quality standards. The elderly and those with chronic pulmonary and cardiovascular disease appear to be at risk for increased mortality from short-term increases in outdoor air pollution. Children with asthma have been found to be a sensitive sub-population for acute responses to outdoor air pollution. Ozone Ozone (O 3 ), a gas with a pungent odor that is often smelled after electrical storms, is bluish in color at higher-than-ambient concentrations. There is much confusion over the difference between "good" ozone and "bad" ozone. "Good" ozone is the diffuse layer of ozone gas in the stratosphere, 10-25 miles above the earth that screens out the sun's most damaging ultraviolet rays. This ozone shield has been damaged by human activities, particularly by chlorofluorocarbons (CFCs), which have been used as refrigerants and aerosol propellants. "Bad" ozone is formed at ground level when reactive hydrocarbons are mixed with nitrogen oxides in the presence of sunlight. This type of ozone is formed only during the daylight hours and is the main photochemical oxidant in smog. April through September are the months when ground-level ozone is a public health concern in most parts of the United States. Exposure to ground-level ozone has been found to result in short-term symptoms such as cough, throat irritation, increased mucous production, chest discomfort, malaise and nausea, and headache. Exercise exacerbates the effects of ozone in susceptible individuals. Except in a few recent projects, chronic effects on lung function due to O 3 exposure have not been shown. However, studies have repeatedly demonstrated transient decreases in lung function due to O 3 exposure. Sulfur Dioxide Sulfur dioxide (SO 2 ) is a colorless, water-soluble gas. It is derived from the combustion of sulfur-containing fossil fuels such as brown coal and oil. Other sources include the smelting of sulfur-containing ores, volcanic eruptions, and the commercial drying of fruits. Ninety percent of SO 2 is absorbed in the upper respiratory tract, with only slight penetration in the lower respiratory tract. Numerous studies have shown that SO 2 exposure is associated with decreases in lung function and increases in hospitalization. This effect is independent from that of particulate air pollution. Although SO 2 levels have decreased in major U.S. cities, SO 2 exposure is still of concern in children with asthma, who may be more susceptible to the bronchoconstrictive effects of SO 2 . Acid Aerosols Acid rain occurs when SO 2 and oxides of nitrogen (NO x ) react with water, oxygen, sunlight, and oxidants in the atmosphere to form acidic aerosols. Acid manufacturing plants and fertilizer and pigment factories are primary sources of acid aerosols. These compounds are also formed when SO 2 or SO 3 come into contact with mucous membranes; excess hospital admissions for respiratory diseases and increases in asthma exacerbations have been associated with airborne sulfate (SO 3 ) levels. Particulate Matter (PM) There are a number of terms for particulate matter (PM): black smoke, TSP (total suspended particles), and PM 10 (particulate matter with an aerodynamic diameter of less than 10 microns). Increasing attention is being paid to smaller "fine" particles (PM 2.5 ), which are deposited more deeply in the lung, and can potentially damage the lower airways and alveoli. The primary sources of particulate matter are vehicular traffic (gasoline and diesel engines), power plants, industrial incinerators, volcanoes, road dust, dust storms, and residential wood combustion. Particulate matter has been associated with increases in the prevalence of chronic bronchitis, respiratory symptoms, and reductions in peak expiratory flow (PEF). Adverse health effects have been found in time-series studies of daily counts of respiratory morbidity and mortality, primarily among persons with respiratory and cardiovascular conditions. Oxides of Nitrogen (NO x ) NO and NO 2 are formed during the burning of fossil fuels, particularly by motor vehicle engines. NO 2 contributes to the formation of ground-level ozone and may contribute significantly to indoor levels of this compound. In the presence of NO 2 , bronchial mucosa may become more permeable to allergens, decreasing the threshold necessary for sensitization and increasing the incidence of allergic asthma. Increased airway responsiveness has been linked to exposure to high levels of ambient NO 2 . In general, however, NO 2 is more of a concern as an indoor rather than outdoor pollutant, and will be further explored below. Indoor Air In contrast to outdoor air pollution, indoor air pollution has increased over the past half-century. Wall-to-wall carpeting came into vogue after World War II, increasing the reservoir of mold and dust mites in the home. The energy crisis of the 1970s led to an increased use of wood stoves for heating, while home construction methods to improve heating and cooling efficiency resulted in more tightly sealed buildings with reduced ventilation rates. Resulting higher humidity and temperatures have also contributed to elevated mold and dust mite allergen levels. The increase in synthetics and chemically formulated products for home furniture, cleaning, and personal care has compounded the problems of inadequate ventilation. Combustion sources (wood stoves, fireplaces, kerosene heaters, gas cooking stoves, tobacco products), asbestos, water-damaged carpeting and furniture, and furniture made of pressed wood products are just a few of the sources of indoor air pollution. Remediation may require removal or control of the source, increased ventilation, and air cleaning devices. The typical American spends 90% of his or her time indoors. Consequently, concerns have been raised that polluted air within homes and other buildings may pose serious health risks. Short-term effects include eye and throat irritation, headaches, dizziness, and fatigue. Symptoms may appear quickly, as in the case of asthma and humidifier fever, a condition with influenza-like symptoms caused by exposure to bioaerosols from contaminated humidifiers. Longer term effects, such as respiratory or heart disease, lung cancer, and even death, have also been documented. Effects may be most severe among those who spend the most time indoors - the young, the elderly, and those with chronic respiratory and cardiovascular conditions. Carbon Monoxide (CO) Carbon monoxide (CO) - "the silent killer" - is an odorless, tasteless, colorless gas produced during incomplete combustion. Sources commonly found in the home include kerosene heaters, auto exhaust, oil heaters, gas stoves, cigarettes, and wood stoves. Recreational sources of CO include ice-resurfacing machines used at ice skating rinks (i.e. Zambonies) and indoor truck and tractor events. Carbon monoxide is one of the most common causes of poisoning death, with an average of 900 unintentional poisonings occurring each year in the United States. Fetuses, infants, the elderly, and people with anemia or a history of heart or respiratory disease are especially susceptible. Symptoms depend on the fraction of hemoglobin converted to carboxyhemoglobin, and range from headache to flu-like symptoms (dizziness, weakness, and vomiting), to deep coma with depressed or absent reflexes, to rapid death from respiratory arrest. Diagnosis can be confirmed by carboxyhemoglobin levels. Nitrogen Dioxide Nitrogen dioxide (NO 2 ), an orange to reddish-brown gas with a pungent odor, causes eye, nose, and throat irritation. Episodes of shortness of breath and even death have been reported at high exposures, especially among asthmatics and children. NO 2 has been associated with delayed-onset bronchiolitis obliterans, while cases of pulmonary edema have been reported among high school hockey players exposed to high levels of NO 2 from ice resurfacing machine (Zamboni) emissions. Some studies have reported that high levels of NO 2 in homes were associated with increased respiratory symptoms and decreased pulmonary function. There is some suggestion that NO 2 enhances airway responses to inhaled allergens in people with asthma. Gas stoves - particularly stoves that are not vented to the outdoors or those with pilot lights - are the primary indoor source of NO 2 . Kerosene and gas space heaters also contribute to indoor levels of NO 2 and should not be used without proper ventilation. Environmental Tobacco Smoke (ETS) More than 10 million American children under the age of five are exposed to cigarette smoke in their homes. A 1992 EPA report concluded that ETS (or second-hand smoke) is responsible for approximately 3,000 lung cancer deaths each year in non-smoking adults and impairment of respiratory health in hundreds of thousands of children. ETS causes 30 times as many lung cancer deaths as all regulated air pollutants combined. Children's exposure to ETS has been linked to an increased risk of chronic respiratory symptoms, bronchitis, pneumonia, chronic middle ear effusions, increased prevalence and severity of asthma, sudden infant death syndrome (SIDS), decrements in pulmonary function, and increased susceptibility to serious infectious diseases such as meningitis. Asbestos Asbestos is the name used for several magnesium silicate minerals that are incombustible, provide insulation against heat, cold and noise, and have great tensile strength. The U.S. Environmental Protection Agency and Consumer Product Safety Commission have banned several asbestos products, and therefore the material is primarily found in older buildings, usually in duct and furnace insulation or in ceiling surfacing materials. Asbestos may also be found in shingles, millboard, textured paints, and floor tiles. Unintentional release of fibers may occur during remodeling, or sanding or cutting these materials. Wood-stove door gaskets and some brands of play-sand made from crushed marble may also contain asbestos. There are no known, short-term health effects or symptoms from exposure to asbestos; however, long-term health effects in adults include increased risk of pleural effusion, lung cancer, mesothelioma, and asbestosis. Smokers are at a substantially higher risk of asbestos-induced lung cancer. Exposure most often occurs in occupational settings; however, children may become exposed from clothing and materials brought home from work sites. Radon Radon is a colorless, odorless, radioactive gas which enters homes through dirt floors, cracks in concrete walls and floors, floor drains and sumps, and sometimes through well water. The greatest concern associated with radon is an increased risk of lung cancer from inhaling the gas. Smaller risks of gastric cancer and leukemia have been associated with drinking water with high radon levels. The EPA estimates that radon causes between 7,000 and 30,000 deaths per year. Radon increases the risk of developing lung cancer in smokers and those exposed to ETS. The federal government recommends that all homes be tested for radon. Inexpensive home testing kits are available in many hardware stores. Formaldehyde Formaldehyde is a colorless gas with a distinct pungent odor which has been classified as a probable human carcinogen. Sources include particle board, plywood, urea-formaldehyde foam insulation, carpet and fabrics, mobile homes, and tobacco smoke. Health effects from formaldehyde exposure are well documented, including headache, eye irritation, nausea, upper respiratory irritation, and allergic reactions. Some asthmatics are especially vulnerable to the respiratory effects of formaldehyde. There is a strong association between living in a mobile home for more than 10 years and the development of squamous cell carcinoma of the nasopharynx. Chemical Solvents in the Home The use and storage of many household chemicals can lead to dangerously high levels of indoor pollutants. These include vapors from organic solvents found in paints, varnishes, and waxes, as well as cleaning, disinfecting, cosmetic, degreasing, and hobby products. The range of health effects, including carcinogenicity, is not known for all of these products, but solvents have been linked to eye and respiratory tract irritation, headaches, dizziness, visual disorders, and memory impairment. Benzene, which is found in paint as well as in tobacco smoke and automobile emissions, is a known human carcinogen. Known animal carcinogens include methylene chloride, which is found in many paint strippers, adhesive removers and aerosol spray paints, and perchloroethylene, which is used in the dry-cleaning process. Volatile organic compounds (VOCs) are suspected of causing symptoms known collectively as "sick building syndrome," characterized by headache, dizziness, and eye irritation. Bioaerosols The indoor environment contains a complex mix of biological contaminants that may contribute to a wide range of health effects. Substances such as bacteria, viruses, molds and spores, and proteins found in animal dander may produce infectious diseases, allergic conditions, irritant and toxic responses, as well as non-specific complaints such as headache, difficulty in concentrating, and drowsiness. Inadequate ventilation often contributes to the growth and accumulation of these indoor pollutants. Infectious diseases Outbreaks of Legionnaires' disease and Pontiac fever have been traced to the aerosolization of the bacteria Legionnella. Humidifier fever has been attributed to a micro-organism that thrives within ventilation systems. Children, the elderly, and those with respiratory diseases are most susceptible. Allergens Allergens are proteins recognized by the immune system as foreign, which prompt the body to mount a specific immune response. These proteins may come from plant and animal sources such as rubber plants (latex), molds, animal dander, cat saliva, house dust mites, cockroaches, and pollen. Some allergens can become airborne and contribute to a wide range of respiratory symptoms, skin irritation, and in severe cases, even death. Increases in the prevalence of indoor allergen sensitization and asthma have been linked to tightly sealed energy-efficient homes that restrict the range of temperature and humidity. Irritant and toxic responses Fungi may release volatile metabolites, causing a moldy smell typically associated with damp basements. Fungi may also release mycotoxins, which are among the most potent carcinogens known and which can have other severe acute and chronic effects in humans. Although airborne exposure to mycotoxin is rare, exposure in occupational settings has resulted in severe health effects. A cluster of 10 cases of pulmonary hemorrhage and hemosiderosis among infants living in moldy and water-damaged homes was linked to exposure to toxigenic Stachybotrys atra and other fungi. Endotoxin, found in the outer membrane of Gram-negative bacteria, can also produce toxic effects. Upon inhalation, endotoxin may cause fever and malaise, changes in white blood cell counts, respiratory tract inflammation and bronchoconstriction, shock, and death. Endotoxin exposure has also been linked with increased severity of asthma. The primary non-occupational source of exposure is contaminated room humidifiers, but indoor pools and fountains can also harbor endotoxin. Special Issues at School or Day-Care Time spent at school or in day-care plays an important role in a child's exposure to toxicants and must be considered in diagnosing health problems. Wide-spread reductions in school budgets have delayed many maintenance projects, resulting, in some cases, in indoor air quality problems. Even buildings with properly functioning ventilation systems may have an abundance of pollution sources that can adversely impact the health and safety of students and school personnel. Some children may be more vulnerable to these effects, including those who wear contact lenses, have allergies, asthma, sensitivities to chemicals, respiratory diseases or depressed immune systems due to radiation, chemotherapy, or disease. Outdoor sources of indoor pollution include pollen, dust, and mold spores as well as vehicle and industrial emissions. Underground sources such as radon, pesticides, and leakage from underground storage tanks should be considered. Within a building, microbiological growth in drip pans, ductwork, and humidifiers can contribute to environmental hazards. Emissions from new furnishings and floorings have been documented to cause respiratory symptoms. Sources not often considered include science laboratories, vocational arts area, food preparation areas, smoking lounges, cleaning materials, emissions from trash, odors and volatile organic compounds from paint, chalk and adhesives, dry-erase markers, and personal care products. Live sources include pets, insects, and occupants with communicable diseases. Case Studies Case Study #1 Three children, aged 6, 10, and 11, were brought to the emergency room after having been found unresponsive in the back of their parents' pickup truck. The youngsters had been sleeping in the back of the truck while their parents completed an all-night road trip. After the first 50 miles of travel, they had stopped at a service station; the children had been awake and alert at that time and did not complain of headache or other problems. During a second stop after driving an additional 250 miles, the children had appeared to be asleep. On arrival at their destination, following a total drive of 550 miles, the children could not be aroused. Resuscitation attempts were unsuccessful. Autopsy examinations revealed that the three children had carboxyhemoglobin levels of 15-20%, 23-28% and 31-36% and that cerebral edema was present in each. No evidence was found for other causes of death. Inspection of the 1970 truck found that the muffler had been replaced, but the original tailpipe was not securely joined to the muffler. Several holes in the wall of the truck bed behind the cab allowed fumes leaking from the muffler to enter the enclosed truck bed. Diagnosis: Fatal carbon monoxide poisoning. Case Study #2 A 7-month-old boy was transferred to a tertiary care center from a community hospital suffering from respiratory distress. He had been well until four days prior, when he had developed rhinorrhea. The day before arrival at the community hospital, he had developed a fever and begun wheezing, with intermittent coughing and choking spells. His medical history showed that he had been born at 32 weeks gestation, weighing 1200 grams (2 lbs., 9 oz.). Respiratory distress syndrome was treated with continuous positive airway pressure for the first month of his two-month stay in the premature nursery. He was discharged to home at 3 months of age on a respiratory monitor because he continued to experience periods of apnea and bradycardia. Significant illnesses since then had included episodes of bronchiolitis at ages 5 months and 6 months, neither of which required hospitalization. Social history revealed that both the mother and father smoked a pack of cigarettes a day. Neither of them took any special precautions not to smoke around the baby. The father was employed in retail sales; the mother did not work outside the home. Physical examination revealed a sick-looking infant in respiratory distress. His temperature was 39.9 C (rectal), pulse 144, and respiration 68 and shallow. His weight was in the 5th percentile for his age. No skin rash or cyanosis was present. He had clear rhinorrhea and nasal flaring. Chest examination revealed intercostal and subcostal retractions and bilateral scattered expiratory wheezes. The expiratory phase of breathing was prolonged. The heart and abdomen were normal. X-ray films of the chest revealed bilateral hyperinflation of the lungs with subsegmental atelectasis in both lower lobes as well as the right upper lobe. Fluorescent antibody test for respiratory syncytial virus antigen was positive, as was viral culture for respiratory syncytial virus (RSV). Diagnosis: Bronchiolitis caused by RSV. Passive exposure to ETS is a primary risk factor for hospital admission for RSV and other lower respiratory tract disease. It has been estimated that there is an annual excess of 22,000 hospitalizations and 1,100 deaths due to RSV bronchiolitis attributable to parental smoking. Questions For Discussion The answers below are not comprehensive, but are meant to be a starting point for discussion with your students or residents.
Field Work And Next Steps
Learning Methods
Evaluation Methods
Hand-Outs For Parents Nine Indoor Air Hazards
Adapted from the following source: http://www.montana.edu/wwwcxair/#ten Signs of Possible Home Indoor Air Quality Problems A major hazard is misinformation. Be informed. Be alert for these signs:
Source: http://www.montana.edu/wwwcxair/#ten Outdoor Air Pollution Recommendations for Parents
Preventing Carbon Monoxide Poisoning Recommendations for Parents
Preventing NO 2 Poisoning Recommendations for Parents
Preventing Environmental Tobacco Smoke (ETS) Exposure Recommendations for Parents
Preventing Asbestos Exposure Recommendations for Parents
Preventing Radon Exposure Recommendations for Parents
Preventing Formaldehyde Exposure Recommendations for Parents
Preventing Exposure to Organic Solvents from Household Products Recommendations for Parents
Preventing Exposure to Bioaerosols in the Home Recommendations for Parents Routine Modifications:
Modifications for children with allergies or other conditions that make them more susceptible to bioaerosols:
Improving the Environment at School or Day-care Recommendations for Parents
Resources General Information on Outdoor Air Quality Contact your regional EPA office for information on local pollution or search the following website, using your own zip code: http://www.epa.gov/enviro/zipcode_js.html General Information on Indoor Air Quality http://www.epa.gov/iaq/pubs/insidest.html Indoor Air Pollution: An Introduction for Health Professionals http://www.epa.gov/iaq/aiqinfo.html EPA Indoor Air Quality Information Clearinghouse PO Box 37113
Asthma and Allergy Foundation of America (800) 778-2232 Indoor Air Quality in Schools http://www.epa.gov/iaq/schools/index.html IAQ Tools for Schools Action Kit To order: 1-800-438-4318 Carbon Monoxide Detectors The Quantum Group, Inc.
3946 South Mariposa Street
Environmental Tobacco Smoke National American Lung Association Headquarters
Office on Smoking and Health
Toxic Substances and Asbestos Toxic Substances Control Act Assistance Information Service
Radon Regional EPA office distributes the Citizen's Guide to Radon
Mattress and Pillow Covers Allergy Control Products
Bibliography General References Bates DV. The effects of air pollution on children. Environ Health Perspect 103S:49-53 (1995). Bates DV. Observations on Asthma. Environ Health Perspect 103(S6):243-247. Etzel RA. Indoor air pollution and childhood asthma: effective environmental interventions. Environ Health Perspect 103S:55-58 (1995). Goldman LR. Children - unique and vulnerable. Environmental risks facing children and recommendations for response. Environ Health Perspect 103S:13-18 (1995) http://www.epa.gov/aiq/pubs/insidest.html. August 25, 1998. http://www.epa. gov/aiq/schools/index.html. August 25, 1998. Raizenne M, Dales R, Burnett R. Air pollution exposures and children's health. Can J Public Health 89S:S43-S48 (1998). Outdoor Air Pollution American Academy of Pediatrics. Committee on Environmental Health. Ambient air pollution: Respiratory hazards to children. Pediatrics 91:1210-1213 (1993). CDC. Children at risk from ozone air pollution - United States. MMWR 44(16) 309-312 (1995). Gielen MH, van der Zee SC, van Wijnen JH, van Steen CJ, Brunekreef B. Acute effects of summer air pollution on respiratory health of asthmatic children. Am J Respir Crit Care Med 155(6):2105-2108 (1997) http://www.epa.gov/ardpublc/acidrain/effects/envben.html. September 9, 1998. Peters A, Dockery DW, Heinrich J, Wichmann HE. Short-term effects of particulate air pollution on respiratory morbidity in asthmatic children. Eur Respir J 10(4):872-879 (1997) Schwartz J. What are people dying of on high pollution days? Environ Res 64(1):26-35 (1994). Wardlaw AJ. Air pollution and allergic disease. Report of a Working Party of the British Society for Allergy and Clinical Immunology. Clin Exp Allergy 25S3:6-8 (1995). Weinmann GC. An update on air pollution. Curr Opin Pulm Med 2(2):121-128 (1996). Indoor Air pollution Honicky RE, Osborne JS, Akpom CA. Symptoms of respiratory illness in young children and the use of wood-burning stoves for indoor heating. Pediatrics 75:587-93 (1985). http://www.epa.gov/aiq/pubs/insidest.html. August 25, 1998. Robin LF, Less PS, Winget M, Steinhoff M, Moulton LH, Santosham M, Correa A. Wood-burning stoves and lower respiratory illnesses in Navajo children. Pediatr Infect Dis J 15(10):859-865 (1996). Utell MJ, Looney RJ. Environmentally induced asthma. Toxicol Lett 82-83:47-53 (1995). Carbon Monoxide Baker MD, Henretig FM, Ludwig S. Carboxyhemoglobin levels in children with nonspecific flu-like symptoms. J Pediatr 113:501-504 (1988). Cobb N, Etzel RA. Unintentional carbon monoxide-related deaths in the United States, 1979 - 1988. J Am Med Assn 266:659-663 (1991). CDC. Carbon monoxide poisoning at an ice skating rink - Colorado. MMWR 35:435-6, 441 (1986). CDC. Fatal carbon monoxide poisoning in a camper-trucker - Georgia. MMWR 40:154-155 (1990). http://www.epa.gov/iaq/coftsht.html. August 25, 1998. Nitrogen Dioxide Berglund M, Braback L, Bylin G, Jonson JO, Vahter M. Personal NO 2 exposure monitoring shows high exposure among ice-skating schoolchildren. Arch Environ Health 49:17-24 (1994). Neas LM, Dockery DW, Ware JH, Spengler JD, Speizer FE, Ferris BG Jr. Association of indoor nitrogen dioxide with respiratory symptoms and pulmonary function in children. Am J Epidemiol 134(2):204-219 (1991). Pilotto LS, Douglas RM, Attewell RG, Wilson Sr. Respiratory effects associated with indoor nitrogen dioxide exposures in children. Int J Epidemiol 26(4):788-796 (1997). Environmental Tobacco Smoke Aligne CA, Stoddard JJ. Tobacco and children. An economic evaluation of the medical effects of parental smoking. Arch Pediatr Adolesc Med 151(7):648-53 (1997). American Academy of Pediatrics. Committee on Environmental Health. Environmental tobacco smoke: A hazard to children. Pediatrics 99:639-642 (1997). Berg AT, Shapiro ED, Capobianco LA. Group day care and the risk of serious infectious illnesses. Am J Epidemiology 133:54-163 (1991). Colley JRT, Holland WW, Corkhill RT. Influence of passive smoking and parental phlegm on pneumonia and bronchitis in early childhood. Lancet 2:1031-4 (1974). Asbestos American Academy of Pediatrics. Committee on Environmental Hazards. Asbestos exposure in schools. Pediatrics 79:801-805 (1987). Council on Scientific Affairs, American Medical Association. Asbestos removal, health hazards, and the EPA. J Am Med Assn 266:696-697 (1991). Germine M. Asbestos in play sand. N Engl J Med 315:891 (1986). http://www.epa.gov/iaq/asbestos.html. August 25, 1998. Hughes JF, Weill H. Asbestos exposure - Quantitative assessment of risk. Am Rev Respir Dis 133:5-13 (1986). Smith AH, Handley MA, Wood R. Epidemiologic evidence indicates asbestos causes laryngeal cancer. J Occup Med 32:499-507 (1990). Webber JS, Janulis R, Syrotynski S. Examining play sand products for asbestos contamination. Bull Environ Contam Toxicol 45:486-494 (1990). Radon American Academy of Pediatrics. Committee on Environmental Hazards. Radon Exposure: A hazard to children. Pediatrics 83:799 (1989). CDC. Health hazards associated with elevated levels of indoor radon - Pennsylvania. MMWR 34:657-658 (1985). Collman GW, Loomis DP, Sandler DP. Childhood cancer mortality and radon concentration in drinking water in North Carolina. Br J Cancer 63(4):626-9 (1991). Council on Scientific Affairs. American Medical Association. Radon in homes. JAMA 258:668-672 (1987). http://www.epa.gov/aiq/pubs/insidest.html. August 25, 1998. Kjellberg S, Wiseman JS. The relationship of radon to gastrointestinal malignancies. Am Surg 61(9):822-5 (1995). Formaldehyde Bernstein RS, Stayner LT, Elliott LJ, Kimbrough R, Falk H, Blade L. Inhalation exposure to formaldehyde: An overview of its toxicology, epidemiology, monitoring, and control. Am Ind Hyg Assoc J 45:778-785 (1984). Council on Scientific Affairs, American Medical Association. Formaldehyde. JAMA 261:1183-1187 (1989). Schenker MB, Weiss ST, Murawski BJ. Health effects of residence in homes with urea formaldehyde foam insulation: A pilot study. Environ Internat 8:359-363 (1982). Wantke F, Demmer CM, Tappler P, Gotz M, Jarish R. Exposure to gaseous formaldehyde induces IgE-mediated sensitization to formaldehyde in school-children. Clin Exp Allergy 26(3):276-280 (1996). Bioaerosols American Academy of Pediatrics. Toxic effects of indoor molds. Pediatrics 101:712-714 (1998). Burge, HA. Bioaerosols. Boca Raton, FL: CRC Press, Inc., 1995. Etzel RA, Montana E, Sorenson WG et al. Acute pulmonary hemorrhage in infants associated with exposure to Stachybotrys atra and other fungi. Arch Pediatr Adolesc Med 152:757-762 (1998). http://www.epa.gov/aiq/pubs/insidest.html. August 25, 1998. Yang CY, Chiu JF, Chiu HF, Kao WY. Damp housing conditions and respiratory symptoms in primary school children. Pediatr Pulmonol 24(2):73-77 (1997). Air quality in schools |
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