Exposure to a class of chemicals used to make a wide range of consumer products can cause changes in thyroid function, according to a new study.
People have widespread exposure to perfluorinated chemicals (PFCs), which are used to manufacture items such as fabrics, carpets, cosmetics, and paper coatings. These chemicals break down very slowly and take a long time to leave the body.
For this study, researchers analyzed 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. The study looked at levels of four different PFCs as well as participants' thyroid function.
Along with finding that having higher 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 in women.
Hypothyroidism occurs when the thyroid gland does not produce enough hormones. This can lead to symptoms such as fatigue, mental depression, weight gain, feeling cold, dry skin and hair, constipation and menstrual irregularities.
The study was published online in the Journal of Clinical Endocrinology & Metabolism.
"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," study co-author Chien-Yu Lin, M.D., of En Chu Kong Hospital in Taiwan, said in a journal news release.
"Although some PFCs . . . have been phased out of production by major manufacturers, these endocrine-disrupting chemicals remain a concern because they linger in the body for extended periods," Dr. Lin said. "Too little information is available about the possible long-term effects these chemicals could have on human health."