Although nail polish, shampoos and vinyl flooring may seem harmless, these common household goods may pose a health risk to children. Exposure to phthalates, widely used chemical compounds found in these products, is associated with depressed thyroid function in young girls, according to findings from a study published in the journal Environment International, reports Columbia University.

Phthalates, sometimes referred to as plasticizers, are used to increase the elasticity of different products. They’re found in building materials, shampoos and fragrances, among many other consumer items. (Until the Consumer Product Safety Commission banned their use in children’s toys eight years ago, manufacturers included phthalates in such kiddie faves as rubber duckies and soft vinyl blocks.)

For the study, researchers at Columbia University’s Mailman School of Public Health collected data from 229 pregnant women and 229 3-year-olds. Findings showed that lower levels of the active thyroid hormone free thyroxin (FT4) in girls were associated with four phthalates: mono-n-butyl phthalate (MnBP), mono isobutyl phthalate (MiBP), monobenzyl phthalate (MBzP) and monoethyl phthalate (MEP).

According to scientists, thyroid disturbances are more common in women, rendering them more vulnerable to thyroid-disrupting chemicals, even at a young age. “The thyroid acts as the master controller of brain development,” said Pam Factor-Litvak, PhD, the senior author of the study. “Thyroid hormones set the schedule, and if the timing is out of sync, there may be later consequences in the brain. The thyroid disruptions we see in this study, although they fall within the normal range, could explain some of the cognitive problems we see in children exposed to phthalates, and we are currently investigating that. As we know from lead, even small exposures can make a big difference.”

Factor-Litvak suggested that as a precaution parents keep products containing phthalates out of their homes. She also stressed that more research is needed to learn about the potential threat phthalates may pose to children.

Click here to read what experts advise about treating pregnant women who suffer from low thyroid issues.chem