1. 1 Health Effects of ETS  Nonsmokers are exposed to ETS, the mixture of smoke from the smoldering cigarette and exhaled smoke.  This complex mixture contains many of the injurious agents inhaled by active smokers, although the concentrations are diluted.  Nonsmokers exposed involuntarily to ETS often have detectable levels of nicotine and of cotinine, a metabolite of nicotine, in body fluids (blood and urine)  Studies of smoking parents and their children provided the first evidence that passive smoking has adverse health effects.  Maternal smoking was found to place infants at increased risk for lower respiratory tract infections  smoking by household members, particularly the mother, was shown to increase the incidence of chronic respiratory symptoms and reduce the level of lung function in children.  Other studies showed that ETS irritates the upper respiratory tract and eyes

2. 2 Health Effects of ETS  Increased risk of lung cancer for exposed nonsmokers ("passive" smokers) was first reported in 1981. Since then, many studies have addressed this association; pooling of the data indicates that nonsmokers married to smokers have about a 25% greater risk of lung cancer than those married to "never smokers".  Several studies have suggested that ETS exposure reduces lung function in nonsmokers and increases the risk for ischemic heart disease.  Other proposed associations of involuntary smoking with disease include increased risk for cancers at sites other than the lung, younger age at menopause, increased risk for sudden infant death syndrome, and reduced birth weight.

3. 3 Health Effects of Nitrogen Dioxide  Nitrogen dioxide is an oxidant gas that at high concentrations causes lung injury.  Toxicologic studies have shown that it reduces the efficacy of lung defense mechanisms against infection. Some studies suggest that short-term exposure may exacerbate asthma.  Thus, the potential health effects of exposure to nitrogen dioxide indoors include:  increased respiratory tract infection from effects of defense mechanisms  increased respiratory tract symptoms, and reduced lung function from direct inflammation  deterioration of the health status of persons with chronic respiratory diseases, particularly asthma

4. 4 Health Effects of Microbiologic Agents  Biologic agents represent an extremely diverse group that cause disease primarily through infection and immune mechanisms.  The potential for transmission of many infectious diseases through inhalation of indoor air has been recognized for many years (‘common cold’, TB, etc.).  Hypersensitivity pneumonitis and humidifier fever have been linked to central and room humidifiers, contaminated heating and cooling systems, moisture- damaged building materials, cool mist vaporizers, and automobile air conditioning systems.  Legionnaires' disease, an acute bacterial infection caused by Legionella pneumophila, was first described following an 1976 epidemic in Philadelphia. Airborne transmission of this organism from contaminated water in cooling towers is well documented.

5. 5 Health Effects of Microbiologic Agents  Biologic aerosols in buildings may give rise to a variety of syndromes ranging from malaise to infective pneumonias.  Example: in a survey of 12 town halls in Denmark, general dizziness and concentration problems, as well as mucous membrane irritation of the upper respiratory tract were associated with the concentration of Gram- negative bacteria (endotoxin) in surface dust samples  Asthma may be exacerbated by allergens in outdoor and indoor air

6. 6 The major allergen house dust mite has been linked to exacerbation of asthma in a large number of studies, and asthma causation has been suggested by a few studies.

7. 7 Insects such as cockroaches are now recognized as an important source of allergens, primarily in urban housing

8. 8 Cat dander causes symptoms in many asthmatics. It is a sticky allergen which can be detected in homes cat-free for many months, as well as in schools. 

9. 9 Health Effects of Formaldehyde and Other VOCs  Controversy remains concerning the health effects of these indoor pollutants  Formaldehyde is known to be toxic at high concentrations and to be irritating to the respiratory tract  Associations with respiratory morbidity and neurobehavioral impairment, demonstrated in some studies, have not yet been conclusively established.  Formaldehyde causes nasal cancer in rats exposed to high concentrations and is a suspected occupational carcinogen  Airborne formaldehyde acts as an irritant to the conjunctiva and upper and lower respiratory tract.  Symptoms are reversible and, depending on the level and length of exposure, may range from burning or tingling sensations in the eyes, nose, and throat to chest tightness and wheezing.  The other VOCs may also have short- and long-term health effects, but human data are largely lacking.

10. 10 Health Effects of Pesticides  Pesticides sold for household use, notably impregnated strips, and foggers, or insecticide "bombs" (technically classified as semi-VOCs), include a variety of chemicals in various forms.  Exposure to pesticides are most likely to cause harm if they are used improperly  However, exposure via inhalation of spray mists may also occur during normal use.  Children in close contact with contaminated surfaces are at risk of exposure via inhalation of vapors and contaminated dusts, as well as through skin absorption.  Symptoms may include headache, dizziness, muscular weakness, and nausea  Some pesticides have active ingredients and inert components which are considered possible human carcinogens.

11. 11 Health Effects of Radon  The effect of concern is lung cancer  Inhalation of radon and its daughters results in localized exposure of respiratory tract epithelial tissue to ionizing radiation (alpha particles)  Radon is estimated to cause about 14,000 deaths per year in the U.S. (range of estimates from 7,000 to 30,000)  This makes radon second only to tobacco smoking as an environmental risk factor for lung cancer

12. 12 Ambient Versus Indoor Air Pollution: Magnitudes of Health Effects  Numerous studies have repeatedly found statistically significant relationships between fluctuations in ambient air pollution measures, most often particulate and ozone, with acute increases in cardiorespiratory morbidity and mortality.  However, the magnitude of the found effects have generally been modest, in the order of five to, at most, 40 percent increases.  Much stronger associations have been demonstrated for certain indoor air pollutants.  These associations have been particularly strong for the relationship of allergen content in house dust and morbidity rates among children with asthma who have demonstrated sensitization to the allergens present in the dust.

13. 13 The Role Of Cockroach Allergy and Exposure To Cockroach Allergen In Causing Morbidity Among Inner-city Children With Asthma

14. 14 Interactions between Ambient and Indoor Air Pollution  There is intriguing evidence that fluctuations in ambient pollution levels may potentiate the ability of allergens present in household dust to precipitate inflammatory responses and asthma attacks in sensitized children. For example:  Pre-exposure to ozone has been shown to increase bronchial responsiveness to allergens in two human experimental studies.  Diesel exhaust particulate has been shown to enhance antigen-induced airway inflammation in mice immunized with mite allergen, and to increase markers of inflammation upon ragweed antigen challenge in allergic human subjects.

15. 15 Control of Indoor Air Pollutants  Control strategies are often complex, highly variable, and specific dependent on the pollutants of concern and their sources  While, in general, control strategies are beyond the scope of this presentation, the following chart will give a flavor for the various approaches

16. 16 Pollutant Control Measures