 | Click the icon to see an image of fungus. |
Reducing Exposure to Air Pollution. A number of studies have linked air pollution to asthma. An important 2000 study found a strong association between higher mortality rates from heart and lung diseases and high levels of specific pollutants (ozone, carbon monoxide, sulfur dioxide, and nitrogen dioxide). Some experts point out that asthma rates in North America have increased over recent years while the prevalence of many common air pollutants have declined. So pollution is unlikely to be a primary cause of asthma. Nevertheless, evidence strongly suggests that air pollution can worsen existing asthma and patients should take precautions if they are exposed to polluted air.
Occupational Asthma and Reducing Risk
A number of studies have estimated that between 2 - 26% of adult-asthma cases are related to work history. Some experts encourage doctors to suspect occupational factors in all cases of adult-onset asthma. Although workers who have allergies, who smoke, or both are at higher risk than others, any worker exposed to occupational triggers may be at risk for asthma.
Work-related asthma is one of two types:
- Work-aggravated asthma, in which existing asthma symptoms are triggered by irritants at the workplace.
- Occupational asthma, which is new-onset asthma strongly associated with conditions at work.
Occupational asthma is further categorized as:
- Nonlatent (symptoms occur right after exposure to an irritant, usually high concentrations of gas, fumes, dust, or chemicals).
- Latent (symptoms develop after prolonged exposure to substances in the workplace).
Occupational Triggers. Over 250 substances have been identified as potential occupational triggers of asthma and the list is growing. A few of these chemicals and substances include:
- Isocyanates used in the manufacture of polyurethane, paints, steel, and electronics
- Trimellitic anhydrides (TMA) used in many plastics and epoxies
- Western red cedar, oak, redwood, and mahogany
- Metal salts (platinum, nickel, and chrome) and metal working fluids
- Vegetable dusts (soybeans, grains, flour, cotton, and gums)
- Biologic organisms (Bacillus subtilis, pancreatic enzymes)
- Xylanase used in the baking industry
- Pharmaceuticals (penicillin, phenylglycine acid chloride)
- Glutaraldehyde used to sterilize medical equipment
- Red dye made from the cochineal insect
- Diacetyl, the main chemical in artificial butter flavoring used in popcorn
Previous Section
