Phthalates are common in hair and bath products. Photo by Parenting Patch/CC.
NEW YORK, Dec. 10 (UPI) -- Heightened prenatal exposure to two phthalates, a type of chemical commonly used in plastics, has been linked to lower IQ scores, researchers say.
The study -- conducted by researchers at the Mailman School of Public Health at Columbia University found and published Wednesday in the journal PLOS ONE -- found that the seven-year-old children of mothers most exposed to high levels of di-n-butyl phthalate (DnBP) and di-isobutyl phthalate (DiBP) had IQ scores that were six to eight points lower than their least-exposed peers.
"I think we were quite surprised, not about the IQ results but by how large the disparity was," lead study author Pam Factor-Litvak, epidemiologist at the Mailman School, told Fox News.
The study used data compiled as part of the Columbia Center for Children's Environmental Health (CCCEH) longitudinal birth cohort study -- a study that followed and observed the health of 328 low-income New York City mothers and their children. The survey was intended to tease out relationships between environmental contaminants and children's health problems.
In addition to their common use as a plasticizers, phthalates are often found in the synthetic fragrances that augment shampoos, air fresheners and dryer sheets.
Researchers involved in the survey and study relied on urine samples of pregnant mothers that tested for the presence of four phthalates. Those tests were later compared with the children's IQ tests at age seven. While the results don't show a causation, scientists say the fact that researchers followed study participants over time lends credence to the results.
The study's authors, however, admit that a study involving a larger swath of the population is necessary in order to hone in on possible cause and effect. Still, researchers already have their theories about how the two chemicals could be repressing IQ scores.
Factor-Litvak told Live Science that the two chemicals may be disrupting hormones, such as thyroid levels, which are central to early brain development. "They may also modulate the activity of an enzyme called aromatase," she said. Aromatase works to convert testosterone into estrogen, a key neurodevelopmental hormone.
