UCLA researchers have discovered that victims afflicted by
Severe Acute Respiratory Syndrome are more likely to die from the
virus if they live in cities with high pollution levels.
A study, led by scientists from the UCLA School of Public
Health, found a high correlation between SARS death rates and areas
of high pollution as measured by the Environmental Protection
Agency.
According to UCLA Public Health school professor Zuo-Feng Zhang,
results indicated that areas considered to be highly polluted by
the EPA also coincided with death rates of approximately 8 percent,
while areas with low to moderate pollution only had death rates of
about 4 percent.
“Air pollution may increase the risk of dying from
SARS,” said John Froines, director of UCLA’s Southern
California Particle Center and Supersite. “It may weaken the
immune system and result in inflammatory responses which can
increase mortality in certain populations.”
These populations include children and the elderly, Froines
said, who are generally more vulnerable to the chronic effects of
pollution.
Since the virus first emerged, Chinese officials have recorded
5,327 registered cases of SARS, with 349 deaths.
Most deaths associated with SARS are caused by lung failure and
breathing problems, Zhang said, as a direct result of lung
inflammation and tissue damage.
“Air pollution damages the lining of the lung and the
bronchial tube,” he said. “If people with damaged
airways got SARS, the symptoms for them would be much
worse.”
SARS symptoms include fever, coughing and breathing
difficulties.
But Froines said air pollution can cause much more severe
damage.
“Small particles penetrate cells, get into the circulatory
system and get into organs like the brain and the heart,” he
said.
“If you have someone who is already sick, this would
further weaken an immune system already under stress,” he
added, saying that such pollution also damages organs.
While air pollution has previously been linked with lung cancer,
the exacerbation of asthma, and other respiratory problems, Froines
said this study should stimulate more research looking at the
interaction between infectious diseases and environmental
agents.
“The key is to conduct more studies on whether there is
further evidence for this,” he said.
Additionally, Zhang suggested that physicians tending to SARS
infected patients should now prioritize those who live in heavily
polluted areas or have smoking habits.
Victims of the virus should also avoid exposure to air pollution
once they are infected, Zhang said.
The study, which focused on all cases detected in mainland China
between November 2002 and July 2003, was conducted in association
with the Jiangsu Provincial Center for Disease Control and
Prevention, and Fudan University School of Public Health, both in
China.