Clinicians prescribing exercise: is air pollution a hazard?

In reply: As emphasised in my editorial, regular aerobic exercise is to be encouraged, as it is of undeniable benefit to health.1 The crux of the intended message was for people to undertake an exercise program, but not near busy roads. There was no suggestion to curtail outdoor activities.

Although the effect of traffic pollution on an individual is not well understood, there are many hundreds of scientific papers consistently finding that whole automotive pollution, or components thereof, damage biological tissue and promote disease.2 The World Health Organization recognises urban air pollution as a major risk to human health, with exposure to particulate matter alone accounting for an estimated 800 000 deaths a year globally.3

Would it be ethical to confine this information to the annals of scientific literature, or should some attempt be made to inform those who may be unknowingly and unnecessarily exposing themselves to veritable risk? People should have access to all the available information so that they can make an informed decision on where to exercise. Not only is it common sense, but it is entirely reasonable to suggest that people would be better off avoiding exercise alongside roadways congested with traffic.

Quite separate to the question of exercising beside busy roads, but equally important from a health perspective, is the issue of persistently high ambient levels of particulate air pollution in certain regions. The air quality problem encountered in Wagga Wagga is exacerbated by geographical and climatic factors that encourage entrapment of air pollution, owing to a temperature inversion layer that is particularly apparent during winter. Other cities, such as Launceston, Tasmania, suffer the same fate and, in both cases, smoke from domestic wood-heaters is thought to be the biggest contributor to poor air quality.

What are people to be told regarding exercise in these regions? It may be reasonably argued that habitual exercise in such environments would be detrimental to health, but it would be a very poor public health outcome if people were advised to stop exercising. In the affected areas mentioned, community education programs have been in existence for years, but these appear to be of limited value, as daily air pollution limits are regularly exceeded,4 as highlighted by du Plessis. Although unpopular, the answer lies in stricter regulations to clean the air, such as banning wood-heaters and tighter monitoring of rural burning.