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 sourceswhen simultaneously present at high levelsappear 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