Word: perera
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...released as a vapor and also cling to fine, breathable particles emitted from car and truck engines and coal-fired plants. This kind of pollution is common in urban areas and tends to be particularly bad in poor neighborhoods with heavy car and truck traffic and idling. But, Perera notes, these pollutants are widespread enough to affect populations other than those living in poor, urban areas...
...quality. Based on the results, they were divided into high-PAH-exposure and low-exposure groups. The mothers were healthy, nonsmoking black and Dominican-American women, ages 18 to 35, living in northern Manhattan and the South Bronx - not far from Columbia's Mailman School of Public Health, where Perera is a professor. (Read "The Risks [and Rewards] of Pills and Pregnancy...
Earlier reports from Perera's group had found that higher prenatal exposure to PAHs is associated with lower weight and smaller head size at birth and developmental delays at age 3. Studies of children in China who live near coal-burning plants have found that PAH exposure is associated with delayed motor development. The current Pediatrics study, however, is the first to link exposure to reduced performance on IQ tests. Kids in the low-exposure group scored a mean IQ of 101.6, while the mean score in the high-exposure group...
...surprising that the effects [of prenatal exposure] are so persistent," says Kimberly Gray, an epidemiologist at the National Institute of Environmental Health Studies, which helped fund Perera's study. By following these children through age 11, she says, the Columbia team will be able to look for links to learning disorders and attention-deficit disorder...
Precisely how PAHs might harm the developing brain is unclear, though more than one mechanism may be at work. "We know from many studies that the developing fetal brain is particularly vulnerable to neurotoxic chemicals," says Perera. "One of the reasons is that it is rapidly developing. The defense mechanisms present in the adult are not present in the fetus: these include detoxification and repair enzymes." Exposure to pollution could cause direct genetic damage or epigenetic changes, which are changes in how genes are expressed...