The first ever review of scientific studies on the health effects of outdoor air pollution in Asian cities underscores the fact that the impact of the scourge is as lethal in this part of the world as in Europe and the us. The assessment was done by the Boston (us)-based research body, Health Effects Institute (hei), and released recently in New Delhi.

Entitled Health Effects of Outdoor Air Pollution in Developing Countries of Asia: A Literature Review, the study is a part of the Public Health and Air Pollution in Asia Program (papa) that was undertaken by hei in partnership with the Clean Air Initiative for Asian Cities (cai Asia). The latter is a network of air quality regulators, development agencies, non-governmental organisations, industry and cities in Asia. papa seeks to inform regional policymakers about the state of the science concerning air pollution and health in major cities of the continent.

hei president Daniel Greenbaum observes: "This assessment is the first systematic identification of all peer-reviewed Asian studies on the effects of air pollution on health. It found that a considerable body of science currently exists across Asia (on the subject).'

In assessing existing evidence on the health toll of air pollution in Asian cities, the report has found that an increase in respirable suspended particulate matter (pm10) by just 10 microgrammes per cubic metre leads to a 0.5 per cent rise in mortality. Further, an increase in the levels of nitrogen dioxide pushes up hospital admissions with regard to respiratory disorders by 1 per cent. Given the high levels of air pollution in many Asian cities (exceeding 100 microgrammes per cubic metre), the public health impact of this trend could be substantial, warns the study.

hei scientists were surprised by the similarities between the results thrown up by Asian research and those from studies conducted in Europe and the us. They had good reasons to expect, states the report, that the effects of air pollution would be influenced by the difference in age profile, health status and lifestyle between Asian and Western populations, as also by the mixture and toxicity of pollutants. However, studies reviewed so far in Asia do not show much variation from those conducted elsewhere. hei vice-president Robert O'Keefe explains: "The small number of (Asian) cities considered for review limited the comparisons