Richard R. MacMahon, Ph.D.
Asthma is related to the environment through the environmental triggers already mentioned. For a long time it has been stated (Kovesi. 1996) that the most common trigger is dust mites. Recently there have been articles suggesting that cockroaches in low-income houses were the primary trigger under those circumstances (Anon., 1998; Rosenstreich
et al
, 1997). Mold spores in older or damp houses are also often mentioned as being a main trigger. Tobacco smoking by parents is a major cause for the development of asthma in children. And if the mother smokes during pregnancy, the child may even be born with asthma. (Gergen
et al
, 1998)
Other triggers include animal dander (mostly from pets) (Kovesi, 1996) and pollen. The pollen trigger is the same as hay fever, but the result is an asthma attack. One extremely important trigger for asthma attacks is stress. This is not always recognized, but is a very important factor in some people. In children, asthma is often triggered by a cold or the flu. It may also be triggered by exercise in cold, dry air. Aspirin especially and other medications may also trigger asthma attacks. A check list of possible triggers and a self-test is available on the internet at Asthma Triggers (1999).
Finally, there are a number of air pollutants that can trigger asthma (Bethea, 1998). These include organic solvents, various air-borne chemicals such as sulfur dioxide, nitrogen oxide, ozone and a whole host of organic compounds that are part of our modern life. These range all the way from pesticides (Etzel, 1995) to cleaners to catalysts in plastics and paints.
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To summarize, environmental triggers include:
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1. Dust mites
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2. Cockroaches
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3. Smoking
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4. Animal Dander
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5. Pollen
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6. Mold Spores
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7. Stress
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8. Aspirin and other medications
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9. Colds and Flu
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10. Exercise in cold, dry air
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11. Pollutants
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a. Organic solvent aerosols
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b. Air-borne chemicals (Sulfur dioxide, nitrogen oxide, O3 etc.)
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c. Air-borne organic compounds (pesticides, etc.)
Environmental tobacco smoke (ETS) is well documented as an asthmatic trigger (Gergen et al, 1998). In a national health and nutrition survey of children two months through five years of age from 1988-1994, 38% of the children were exposed to ETS in the home and 24% were exposed by maternal smoking during pregnancy. Three conditions were studied - chronic bronchitis, wheezing and asthma. While ETS had little effect on upper respiratory infections or on the respiratory health of children three to five years of age, it did definitely increase the prevalence of asthma. ETS seems to approximately double the prevalence of asthma in children under six years of age (Gergen
et al
, 1998).
Another study by Abulhosn
et at
(1997) looked at the recovery of asthmatic children, from hospitalization for an acute asthma attack, in smoking and non-smoking home environments. The data here is again very clear. Children recovering in a smoking home had approximately three times as many symptomatic days as children recovering in a non-smoking home.The use of a bronchodialator was significantly less in the non-smoking homes (Abulhosn
et at
, 1997).
