Air pollution and health in Asia

The World Health Organisation (WHO) estimated in 2002 that over 500,000 deaths in Asia in the year 2000 were caused by outdoor air pollution exposure, accounting for approximately two thirds of the total global burden of deaths attributed to ambient air pollution. In addition, indoor air pollution from the burning of solid fuel in both rural areas and urban slums contributed an additional 1.1 million deaths.

In 2002, the Health Effects Institute (HEI) initiated the Public Health and Air Pollution in Asia (PAPA) programme to reduce uncertainties about the health effects of exposure to air pollution in Asian cities, and a new report1 from HEI provides a comprehensive literature review to come out of the PAPA programme.

The review describes the current scope of the Asian literature on the health effects of outdoor air pollution. It also includes an assessment of a large number of studies of daily mortality and hospital admissions for cardiovascular and respiratory disease, as well as an analysis of Asian studies of long-term exposure to air pollution and chronic respiratory disease, lung cancer, and adverse reproductive outcomes.

A broad overview of the status of and trends in air pollution sources, emissions, and exposures in Asian countries is included. The Asian health effects studies are compared with those from other regions, such as North America and Europe, and the report identifies gaps in knowledge, and gives recommendations to how these could be addressed.

It is concluded among others that, in broad terms, the effects of short-term exposure in Asian cities are on a par with those observed in hundreds of studies worldwide. The same pollutants — fine particles (PM), ozone (O₃), sulphur dioxide (SO₂), and nitrogen oxides (NOx) — affect in particular older people with chronic cardiovascular or respiratory diseases.

The results of the chronic-effects studies reviewed are said to be broadly consistent with those of studies in other regions, which suggests that long-term exposure to air pollution promotes chronic pulmonary disease and other adverse effects that result in reduced life expectancy.

Incremental improvements in air quality are expected to improve health, even in areas with relatively high ambient concentrations, and health benefits are expected to also result from further reductions in exposure to pollution concentrations below those specified in the WHO guidelines.

Christer Ågren

¹Outdoor Air Pollution and Health in the Developing Countries of Asia: A Comprehensive Review. Special Report 18. Health Effects Institute, November 2010.