Air Pollution, Asthma and Allergy
Which Air Pollutants Cause Respiratory Disease?
Symptoms of asthma and other chronic lung diseases are often precipitated by increased levels of air pollutants including particulates, nitrogen oxides, ozone and sulfur dioxide, all of which may directly irritate the airways. The increased incidence of asthma in the fall and winter may be related to effects of temperature inversion on vehicle-generated pollution, combined with the increased incidence of respiratory virus infection at this time of the year.
The incidence of allergic respiratory disease is high and continuing to increase in populations of urban areas of Westernized countries throughout the world. Air pollution from automobile traffic is one explanation of this public health problem. Diesel exhaust, known to boost the formation of IgE antibodies in experimental animals to make them allergic, could play a part in causing allergy in human populations.
Air inside an air-conditioned home in which there are no smokers, pets or old carpets is usually free of hazardous levels of air pollutants that could cause respiratory disease. In the Southwest evaporative coolers, commonly used instead of refrigerated air conditioning, can increase indoor levels of airborne allergens, particularly mold spores. Tobacco smoke, pets (particularly cats), house dust mites, cockroaches and moldy carpet are common indoor triggers of asthma and rhinitis.