Epidemiological analyses of the relationship between environmental pollution and asthma

Epidemiological studies performed on children and young adults indicate tha t the prevalence of asthma has increased over the past decades in a number of countries. Since genetic determinants alone are unlikely to explain thes e findings, environmental factors are expected to have an important impact on the prevalence of this disease. Environmental pollution, among many othe r factors, may play a role in the initiation and manifestation of asthma. H owever, there is little epidemiological evidence for a causal association b etween the classical major outdoor air pollutants, such as SO2 or particula te matter, and asthma. Evidence for an association between air pollution fr om motor vehicles and asthma is still controversial. Thus the indoor enviro nment and other environmental determinants - including lifestyle factors - are likely to be more important as causes of asthma. Epidemiological studie s are able to evaluate the effects of environmental factors on the health o f human populations in their usual environments. In addition, they can meas ure associations between long-term environmental exposures and health outco mes. By using refined techniques for exposure and disease assessment, as we ll as time and cost-effective study designs, environmental epidemiology wil l increase the knowledge about the role of pollution as a possible cause of asthma. (C) 1998 Elsevier Science Ireland Ltd. AU rights reserved.