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Pollution Damages Young Lungs
Reported December 28, 2009
(Ivanhoe Newswire) -- The synergistic effect of early exposure to
both outdoor traffic-related pollution and indoor endotoxin causes more harm
to developing lungs than one or the other exposure alone.
Environmental health scientists at the University of Cincinnati (UC) College
of Medicine have shown that children exposed to both high levels of
traffic-related particles and indoor endotoxin during early life are six
times more likely to experience persistent wheezing than children exposed to
low levels of these pollutants. Endotoxin, a component of bacteria thought
to trigger an immune response in humans, was measured from dust samples
collected before the children reached one-year-old.
UC environmental health researchers found that 36 percent of the children
studied who were exposed to high levels of both traffic-related pollution
and indoor endotoxin demonstrated persistent wheezing by age 3. Only 11
percent of children exposed to low levels of both indoor and outdoor
allergens experienced wheezing; 18 percent of children exposed to low levels
of indoor endotoxin and high levels of traffic-related particles experienced
persistent wheezing. Endotoxin exposure alone appeared to have little
effect.
"There is a clear synergistic effect from co-exposure to traffic-related
particles and endotoxin above and beyond what you would see with a single
exposure that can be connected to persistent wheezing by age 3," lead author
Patrick Ryan, PhD, assistant professor of environmental health at UC, was
quoted as saying. "These two exposure sources—when simultaneously present at
high levels—appear to work together to negatively impact the health of young
children with developing lungs."
Ryan and colleagues calculated study participants' exposures to
traffic-related particles, such as diesel exhaust. "Traffic-related
particles and endotoxin both seem to trigger an inflammatory response in the
children monitored in this study,” said Ryan. “When put together, that
effect is amplified to have a greater impact on the body's response." He
added, "The earlier in life this type of exposure occurs, the more impact it
may have long term. Lung development occurs in children up through age 18 or
20. Exposure earlier in life to both endotoxin and traffic will have a
greater impact on developing lungs compared to adults whose lungs are
already developed."
SOURCE: American Journal of Respiratory and Critical Care Medicine, December
1, 2009 |
