A new study conducted at the Columbia University Mailman School of Public Health finds that children exposed during pregnancy to elevated levels of phthalates had lower IQ scores. The study, published in the journal PLOS ONE, found that those children had an IQ more than six points lower than the average.
The two chemicals are di-n-butyl phthalate (DnBP) and di-isobutyl phthalate (DiBP). They are found in many consumer products, including plastic food and beverage containers. Phthalates are banned in some children’s toys, but the compounds are rarely listed on ingredient labels so they are difficult to avoid.
In the study, researchers followed 328 New York City women and their children from low income communities. The women’s exposure to four phthalates in their third trimester were measured in urine samples. Children of those women were given IQ tests at age seven.
Children of mothers who had the highest 25% of concentrations of DnBP and DiBP had IQs 6.6 and 7.6 points lower, respectively, than children of mothers exposed to the lowest 25% of concentrations. The study controlled for maternal IQ, maternal education, and home environment. This association was also found in perceptual reasoning, working memory, and processing speed. Two other phthalates had no association with child IQ.
More troubling, the range of phthalate metabolites measured in the urine was well within what the CDC observed in a national sample. Lead author Dr. Pam Factor-Litvak, associated professor of Epidemiology at the University said, “pregnant women across the United States are exposed to Phthalates almost daily, many at levels similar to those that we found were associated with substantial reductions in the IQ of children.”
Scientists and doctors recommend that pregnant women try to limit exposure to phthalates. Do not microwave food in plastic containers, don’t use recyclable plastics labeled as 3, 6, to 7, and avoid using air fresheners and dryer sheets that contain scent.
