New research published in the journal PLOS One suggests that frequent use of certain nail polishes and other consumer products like cosmetics and glues could be lowering your IQ.
Researchers at Columbia University's Mailman School of Public Health have confirmed what previous research has shown: Phthalates, which are found in a variety of plastics, can reduce IQ. The researchers also discovered that di-isobutyl phthalate (DiBP), which is found in nail polish, also has detrimental effects.
The researchers looked at data from 328 Dominican and African-American women and their children. Columbia Center for Children's Environmental Health measured the mothers' phthalate levels during pregnancy and gave the children IQ tests when they reached seven years old.
Children exposed to high concentrations of two of the phthalates, including DiBP, saw reduced IQ scores. And the mothers with the highest rate of exposure also had IQs six to eight points below those in the lowest exposure level — a difference the study authors called a "substantial effect."
To avoid overexposure to phthalates, the study authors recommend avoiding plastics with numbers 3,6, or 7. If your child loves playing dress-up, it also wouldn't hurt to find a natural nail polish brand or to check the ingredient list for DiBP.