Flame retardants, household dust, and thyroid cancer

A new report from Duke University finds an explanation for increases in the frequency of thyroid cancer in household dust.

“Thyroid cancer is the fastest increasing cancer in the U.S., with most of the increase in new cases being papillary thyroid cancer” [PTC], said the study’s lead investigator, Julie Ann Sosa, M.D., MA, professor of surgery and medicine at Duke University School of Medicine in Durham, N.C. “Recent studies suggest that environmental factors may, in part, be responsible for this increase.” (1)

Prior studies have shown that some flame retardants used in the home and in vehicles have a similar chemical structure to thyroid hormones and can disrupt thyroid function.

The study measured the content of household dust as well as the incidence of chemicals in blood samples taken from occupants.  The study used a post facto experimental design with test and control groups.  All of the 140 participants lived in their homes for more than 11 years.

This study established that these flame retardants

1. Appear in household dust in measurable quantities, where they can be inhaled by occupants and
2. The level of two of them found in dust and blood samples are associated with the probability of having PTC.

The two problem chemicals identified in the study as elevating cancer risk belong to a class of chemicals, polybrominated diphenyl ethers (PBDEs).

• Decabromodiphenyl ether (BDE-209). This is the most commonly used retardant, and appears to double the risk for thyroid cancer.
• Tris(2-chloroethyl) phosphate (TCEP).

Participants with high levels of TCEP in their house dust were more than four times as likely to have larger, more aggressive tumors that extended beyond the thyroid, according to the study.

Participants with high levels of BDE-209 in their blood were 14 times more likely to have a version of the cancer that tends to be more aggressive.

Why should you care?  These chemicals are used as flame retardants in plastics (including TV cabinets), furniture, drapery backing, some carpets and in consumer electronics, both in home and in automobiles.  Both exposure to these chemicals and the prevalence of thyroid cancer are increasing.

Note:  This research was funded by Fred and Alice Stanback, the Duke Cancer Institute, and the Nicholas School of the Environment at Duke University, and not by industry sources.

What you need to consider:

• Do you have a home air purification system? Not something that makes the air smell nice, but something that removes dust and other particles from what you breath. Maybe it’s time to invest or upgrade.
• Read the labels on what you buy.

 

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Sources:

1. The Endocrine Society. “Exposure to common flame retardants may raise the risk of papillary thyroid cancer.” ScienceDaily. ScienceDaily, 2 April 2017. <www.sciencedaily.com/releases/2017/04/170402111311.htm>.
2. US Environmental Protection Agency, “Technical Fact Sheet — Polybrominated Diphenyl Ethers (PBDEs) and Polybrominated Bophenyls (PBBs),” January 2014.
3. Wikipedia, “Decabromodiphenyl ether.” https://en.wikipedia.org/wiki/Decabromodiphenyl_ether