Air Pollution May Make SARS More Deadly
Death Rate From SARS Twice as High in Polluted Areas
Nov. 21, 2003 -- People who live in areas of high air pollution
may be twice as likely to die from SARS as those from areas with cleaner
A new study shows the number of deaths caused by SARS (severe
acute respiratory syndrome) in different regions of China increased as air
pollution levels increased during the recent outbreak.
Researchers say that the results suggest that exposure to air
pollutants may compromise lung function and make people more vulnerable to
dying from SARS.
Air Pollution Linked to SARS Deaths
The study, which appears in this week's Environmental
Health: A Global Access Service Source, compared SARS death rates and air
pollution levels in five different regions of China between April and May 2003,
when the majority of SARS cases were diagnosed.
Researchers found that SARS death rates increased as pollution
levels increased, ranging from about 4% in regions with low air pollution to
7.5% and 9% in regions with moderate or high air pollution levels,
Guangdong, the southern region where the outbreak began, had a
low level of air pollution with an air pollution index of 75, according to data
obtained from the Chinese National Environmental Protection Agency. Tianjin had
a high level of air pollution with an air pollution index of more than 100, and
Shanxi, Hebei, and Beijing had moderate air pollution levels.
More Study Needed
Researchers say exposure to air pollutants has previously been
linked to a variety of respiratory disorders, and air pollution may predispose
SARS patients to more severe SARS symptoms.
But researchers say it's too soon to draw firm conclusions
about the link between SARS and air pollution. For example, this study did not
take other factors into account that might also have contributed to the
patients' outcome, such as socioeconomic status, smoking habits, or the
treatment the patients were given.
However, the two regions with the highest SARS death rates,
Beijing and Tianjin, were more urban, and researchers suspect that patients
would have received better medical care in these areas, which lends support to
the role of air pollution in increasing death rates.