A recent study has claimed that children born to women whose urinary phthalate levels during pregnancy were in the top quartile of their study cohort had lower intelligence-quotient (IQ) test scores at age 7 than their peers born to women in the quartile with the lowest exposure. Pam Factor-Litvak, et al., “Persistent Associations between Maternal Prenatal exposure to Phthalates on Child IQ at Age 7 Years,” PLoS ONE, December 2014.

According to Columbia university researchers, who analyzed data from 328 women and their 7-year-old children from the Columbia Center for Children’s environmental Health (CCCeH) longitudinal birth cohort, “child full-scale IQ was inversely associated with prenatal urinary metabolite concentrations of DnBP [di-n-butyl phthalate] and DiBP [di-isobutyl phthalate].” using the fourth  edition Weschler Intelligence scale for Children, the study purport- edly found “significant inverse associations… between maternal prenatal metabolite concentrations of DnBP and DiBP and child processing speed, perceptual reasoning and working memory; DiBP and child verbal comprehension; and BBzP [butylbenzyl phthalate] and child perceptual reasoning.”

“The magnitude of these IQ differences is troubling,” said senior author and CCCeH Deputy Director Robin Whyatt in a December  10, 2014, press release. “A six- or seven-point decline in IQ may have substantial consequences for academic achievement and occupa- tional   potential.”

Based on these findings, the authors reportedly recommend that expectant mothers “take steps to limit exposure by not microwaving food in plastics, avoiding scented products as much as possible, including air fresheners, and dryer sheets, and not using recyclable plastics labeled as 3, 6, or 7.” As lead author Pam Factor-Litvak elaborated, “While there has been some regulation to ban phthalates from toys of young children, there is no legislation governing exposure during pregnancy, which is likely the most sensitive period for brain development. Indeed, phthalates are not required to be on product labeling.”