A new U.S. study indicates that maternal exposure to polluted air during pregnancy correlates with lower IQ test scores in children during childhood, further demonstrating that severely polluted air may impair brain development.
According to a May 20 report by the Associated Press, researchers led by Frederica Perella, director of the Columbia Center for Children's Environmental Health, surveyed 249 children. Their mothers resided in northern Manhattan and southwestern Bronx during pregnancy, areas with varying levels of air pollution primarily from vehicle exhaust.
At age 5, these children underwent IQ testing. Researchers found that children born to mothers exposed to the most polluted air during pregnancy scored 4 to 5 points lower on IQ tests than those born to mothers exposed to less polluted air. Pereira stated this gap is significant enough to impact children's future academic performance.
Researchers noted that 56% of the children studied were exposed to high pollution levels during fetal development. They are investigating whether these mothers lived near crowded neighborhoods or heavily polluted areas like public transit stations during pregnancy.
Pereira noted that researchers also accounted for factors affecting IQ scores like secondhand smoke exposure and home learning environments after birth. Yet they still found a strong association between maternal pollution exposure during pregnancy and children's later IQ levels.
The findings were published in the August issue of the American journal Pediatrics.
In previous research, Pereira suggested that prenatal air pollution exposure could lead to smaller heads, lower birth weights in newborns, or increased risks of genetic mutations.