Greenhouse curbs 'benefit health'

Atlanta 1996: The Olympics showed the benefits of tackling air pollution

By BBC News Online's environment correspondent Alex Kirby

Scientists say there would be significant benefits to public health from a cut in greenhouse gas emissions.

They say emission cuts could eliminate more than 60,000 premature deaths in four cities across the Americas by 2020.

Altogether, they believe, cuts could give immediate relief from air pollution to more than three billion people.

They say air pollution is already damaging or killing millions of those in urban areas.

The scientists are from universities in south, central and north America. Their work is reported in the journal Science.

Leading health threat

They say most public discussion of climate change has focused on long-term problems like increasing temperatures, rising sea levels, and changing patterns of infectious disease.

Darkness as smoke shrouds Kuala Lumpur

But the World Health Organisation ranks deaths from indoor and outdoor air pollution as one of the top ten causes of disability worldwide.

In 1997 WHO, the World Resources Institute and others estimated that nearly 700,000 deaths occur annually which are related to air pollution, with about eight million avoidable deaths expected by 2020.

The authors write: "There is little doubt that air pollution from current patterns of fossil fuel use for electricity generation, transport, industry and housing is already sickening or killing millions throughout the world.

"Increasing power generation by conventional fossil fuel combustion further threatens human health and welfare by increasing air pollution."

They cite as an example of the immediate benefits of improved air quality the experience of Atlanta, Georgia, in 1996, during the Olympic Games.

They write: "When alternative transportation policies during the games reduced vehicle exhaust and related air pollutants (such as ozone) by about 30%, the number of acute asthma attacks and Georgia Medicaid claims fell by 40%, and paediatric emergency admissions dropped 19%."

Weighing the gains

They note an Ontario Medical Association study, which said that for every death from air pollution there were an extra 5.1 hospital admissions, 6.8 emergency room visits, and 24,128 minor illness days.

Studies have also found a doubling of the risk of infant death in some areas with the highest air pollution levels, such as the Czech Republic and Mexico City.

Athens in the smoke: People and buildings suffer

To see how helpful greenhouse gas reductions could be, the authors evaluated the possible health improvements that could be achieved over the next two decades in Sao Paulo (Brazil), Santiago (Chile), Mexico City and New York.

For this combined population of 45 m people, they sought to test the benefits of "existing, readily acquirable technologies that would reduce greenhouse gas emissions from fossil fuels".

They calculate these would reduce particulate matter and ozone ambient concentrations by about 10%, and would avoid:

• about 64,000 premature deaths (including some infant deaths)
• 65,000 chronic bronchitis cases
• 37 m "person-days of restricted activity or work loss".

The scientists say the benefits they project are likely to be conservative.

They write: "This is because we have not included the impacts of other pollutants (such as benzene, polycyclic aromatics, and other toxic air pollutants), and because many effects are not yet quantifiable on the basis of available literature."

They conclude: "For every day that policies to reduce fossil fuel combustion emissions are postponed, deaths and illness related to air pollution will be increased.

"These largely unappreciated air pollution-related health benefits could be a strong motivator for greenhouse gas mitigation action."