[sustran] Re: More evidence on particulate air pollution danger

[Lake Sagaris]

Great posting Nell. Thanks very much. Lake (Santiago, Chile)

At 06:48 PM 8/3/00 +0800, you wrote:
>New Scientist this week reports:
>
>Hold your breath
>Tiny particles of dirt in the air of cities really can kill you 
>
>A FRESH analysis of a classic pollution study has vindicated its conclusion
>that city-dwellers in Europe and the US are dying young because of
>microscopic particles in the air. 
>
>Most of the concern about particulate pollution began in 1993 with the
>publication of the Harvard "Six Cities" study, which identified particles
>with a diameter of less than 10 micrometres (PM10) as a threat to public
>health. A team of researchers at the Harvard School of Public Health in
>Boston, led by Douglas Dockery, compared death rates and pollution levels
>in six American cities by following more than 8000 adults for up to 16
years. 
>
>They found that the death rates increased in almost direct proportion to
>the level of particulate pollution. People living in the most polluted
>city--Steubenville, Ohio--had a 26 per cent risk of dying young compared
>with residents of the cleanest city, which was Portage, Wisconsin (New
>England Journal of Medicine, vol 329, p 1753). 
>
>A larger study by the American Cancer Society in 1995 tested these findings
>by following 550 000 adults over seven years. Once again, there appeared to
>be a strong link between death rates and particulate pollution. Critics of
>these studies argued, however, that other differences between the
>cities--such as poverty--might be responsible for the different death rates. 
>
>So the Health Effects Institute, an independent research organisation in
>Cambridge, Massachusetts, funded jointly by industry and the US
>government's Environmental Protection Agency, spent three years
>re-analysing the data and testing dozens of different explanations for the
>results. They controlled for factors such as education, ethnicity, income
>levels and the availability of health care, as well as differences in other
>pollutants, temperature and humidity. 
>
>But the re-analysis broadly confirmed the original conclusion. "For the
>most part, the inclusion of these additional [factors] did not alter the
>association," says team leader Daniel Krewski of the University of Ottawa.
>"We were very surprised and relieved, actually," says Dockery. Adrian Pope
>of the Brigham Young University in Provo, Utah, who led the American Cancer
>Society study, hopes the results will end the controversy. 
>
>The HEI study suggests that tiny particles with a diameter of less than 2.5
>micrometres, or PM2.5, are more dangerous than PM10. Most of the PM2.5
>fraction is caused by by-products of combustion, which may contain more
>carcinogens. 
>
>Currently the US sets air-quality standards for both PM10 and PM2.5. Europe
>only has a standard for PM10, but the European Commission is due to review
>its particle pollution standards. Roy Harrison of the University of
>Birmingham, who advises the British government on particulate air
>pollution, says separate monitoring is unnecessary because, in Britain at
>least, PM2.5 levels rise and fall with PM10 levels. 
>
>But Tim Brown of Britain's National Society for Clean Air says researchers
>need to know more about how particle composition--and not just
>size--affects health. Brown asks: "Are all particles equally dangerous?"
>
>Nell Boyce 
>
>>From New Scientist magazine, 05 August 2000.
>
>© Copyright New Scientist, RBI Limited 2000
>--------------------------------
>
>
>
>Distributed for the purpose of education and research.
>
>A. Rahman Paul BARTER
>SUSTRAN Resource Centre
>Information services for the Sustainable Transport Action Network
>for Asia and the Pacific (the SUSTRAN Network)
>sustran at po.jaring.my 
>http://www.malaysiakini.com/sustran
>http://www.geocities.com/sustrannet
>
Ojo con cambio de dirección/
Note change of address:
sagaris at lake.cl