News

Air Pollution makes vigorous exercise safe on 30 or less days per year

Hong Kongs average pollution levels are so high that in recent years there have been only about 30 days per year when it would be truly safe to do exercise, according to research carried out by public health experts from Hong Kong University.

This troubling assessment is based on the number of days and the amount by which Hong Kongs air pollution routinely exceeds the World Health Organisations Air Quality Guidelines. It also takes into account that exercise causes faster and deeper breathing, increasing exposure to pollution and amplifying damage to the body.

Anyone taking exercise in Hong Kong needs to be aware of the risks air pollution poses to their health, said Professor Anthony Hedley of the Department of Community Medicine. People here are caught in an impossible dilemma regular exercise is absolutely necessary for good heath - but most of the time it also increases exposure to the harmful effects of air pollution.

Professor Hedley suggested, as a rough guideline, that sports and energetic outdoor activities should be cancelled when the levels of pollutants such as particles and nitrogen dioxide reach around 100 micrograms per cubic metre. This does not mean that pollution levels below 100 micrograms per cubic metre but still well above the WHO guideline are safe, only that the risks are less likely to be severe.

Certainly, any level of pollution above the WHO guidelines poses some health risk. Therefore, the problem becomes one of determining an acceptable level of risk and trying to lead a normal life, added Professor Hedley.

The WHO guidelines, which are based on the best ever studies of the impacts of air pollution worldwide, are much tighter than Hong Kongs own air quality guidelines and the Air Pollution Index, (which is published daily by the Environmental Protection Department at http://www.epd-asg.gov.hk/ As a result the guidance for the public identifying pollution as high low or medium greatly understates the threat to public health.

More information on the costs and impacts of air pollution on public health will be available when a new online tool The Hedley Environmental Index goes live on 18th December.

News Archive

Conference News Items (in chronological order)