A recent study shows that exposure to perfluorinated chemicals (PFCs), a class of chemicals that are commonly used in many consumer products, including cosmetics, can reportedly affect thyroid function. Li-Li Wen, et al., “Association Between Serum Perfluorinated Chemicals and Thyroid Function in U.S. Adults: The National Health and Nutrition Examination Survey 2007- 2010,” Journal of Clinical Endocrinology & Metabolism, July 17, 2013. Analyzing data from more than 1,100 people who took part in the 2007-2008 and 2009-2010 U.S. National Health and Nutrition Examination Survey, researchers looked at levels of four different PFCs as well as participants’ thyroid function, concluding that PFCs break down very slowly and take a long time to leave the body. Along with determining that high levels of PFCs in the body can alter thyroid function in both men and women, the researchers also found that PFCs may increase the risk of mild hypothyroidism—when the thyroid gland does not produce enough hormones—in women.

“Our study is the first to link PFC levels in the blood with changes in thyroid function using a nationally representative survey of American adults,” said study co-author Chien-Yu Lin. Although manufacturers have phased out use of some PFCs, Lin observed that the chemicals remain a concern because they linger in the body for extended periods. “Too little information is available about the possible long-term effects these chemicals could have on human health,” noted Lin. See health.usnews.com, July 17, 2013.