Chemicals in Carpets, Non-Stick Pans Tied to Thyroid Disease

Jan. 22 -- THURSDAY, Jan. 21 (HealthDay News) -- Chemicals found in carpeting, non-stick cookware and fabrics are linked to an increase in thyroid disease, new research suggests.

British researchers analyzed blood serum levels of two types of perfluorinated chemicals in nearly 4,000 U.S. adult men and women, using data from U.S. Centers for Disease Control and Prevention's National Health and Nutrition Examination Survey (NHANES).

Women whose blood levels of perfluorooctanoic acid (PFOA) was in the highest quartile were more than twice as likely to report having thyroid disease as those in the lowest two quartiles. The findings were similar in men, but the results were not statistically significant.

Among men, researchers found an increase in the likelihood of thyroid disease among those who had high levels of perfluoroctane sulphonate (PFOS) in their blood, but the same association was not found in women.

The researchers cautioned that while the data show an association between the chemicals and thyroid disease, they do not prove cause and effect, meaning there could be other explanations for why people with high levels of the compounds in their blood had more thyroid disease.

"We have provided the first evidence of a statistical association between PFOA blood levels and thyroid disease in the 'ordinary' U.S. adult population," said senior study author Tamara Galloway, a professor of ecotoxicology at University of Exeter. "In this type of human population research, it is not possible to be sure whether this is cause or effect. That needs more research."

The study will be published Jan. 21 in the online issue of the journal Environmental Health Perspectives.

Thyroid disease is more common in women than men, and recent reports have found the incidence is rising. Among study participants, about 16 percent of women and 3 percent of men had a thyroid disorder at some point.

Perfluorinated chemicals are pervasive in industrial and consumer products, including food packaging, flame-resistant and waterproof clothing, chemical-resistant tubing and stain-resistant coatings for carpets. The chemicals are chosen for their ability to repel heat, water, grease and stains.