Air Pollution, Health and Exercise: A Review

The effects of air pollution on health are complex. Carbon monoxide, ozone, sulphur dioxide and nitrogen dioxide have received most attention from scientific research. Until recently, however, the role of particulates has been much neglected. While there is a good understanding of the effects of certain pollutants in isolation, there is a poor understanding of the combined effects of different pollutants found in ambient air. The interactions between air pollution, allergic respiratory disease and exercise are the focus of this paper. Epidemiological studies suggest that allergic diseases such as asthma and hay fever have become more common over the last 50 years. Air pollution is not implicated directly, but there is evidence that air pollutants can alter airway reactivity and exacerbate asthma in allergic individuals. Exercise is an important factor because most asthmatics are prone to asthma triggered by moderate to severe exercise. The clinical evidence for health risks associated with atmospheric pollution is considerable, but the epidemiological evidence is less convincing. We find that this field of research is still largely unresolved and is hampered by conflicting use of terminology. In particular, the distinction between allergic disease and (less definitive) ‘sensitivities’ must be clarified. Further research is needed and the associations between sensitivity to air pollutants disease and exercise should be a focus.