Kids whose moms had the highest levels of certain chemicals in their bodies during pregnancy had markedly lower IQs at age 7, according to researchers.
It’s the latest in a series of studies linking the chemicals, called phthalates, with health effects ranging from behavioral disorders to deformations of the sex organs.
While the study doesn’t show for sure that the phthalates damaged the kids’ brains during development, the researchers say they did everything they could to filter out other possible effects and they still found the link between some — but not all — of the phthalates and IQ.
“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,” said Pam Factor-Litvak of the Mailman School of Public Health at Columbia University, who led the study.
Phthalates (pronounced “THAL-ates”) are a group of chemical compounds used to keep other products flexible. They make plastics bendier and are used almost everywhere, from plastic toys and bottles to vinyl flooring and dryer sheets, cosmetics and air freshener.
More than 470 million pounds of phthalates are produced or imported in the United States each year.
They’re also in just about everyone’s bodies. Environmental groups have been worried about them for years, but there had been little evidence they caused any real harm to people. Large doses can affect animals, but the human body processes them out quickly.
Factor-Litvak’s team has been trying to study their effects in kids, and they’ve been watching a group of inner-city New York women and their children since 1998.
The 328 moms gave urine samples when they were pregnant and the mothers and their children have been taking part in all sorts of tests since then.
For this study, the researchers looked at levels of five common phthalates in urine taken from the women during the third trimester of pregnancy.
They included di-n-butyl phthalate (DnBP), butylbenzyl phthalate (BBzP), di-isobutyl phthalate (DiBP), di-2-ethylhexyl phthalate and diethyl phthalate.
Only two of them — DnBP and DiBP — were linked with a real difference in IQ, Factor-Litvak and colleagues wrote in their report, published in the journal PLOS ONE. The children of moms with the highest levels of those two chemicals scored on average four points lower on the IQ test than kids whose mothers had the lowest levels.
Read more from Maggie Fox at Nbcnews.com
