Toxic Tuesdays

Polybrominated diphenyl ethers (PCBEs)

Toxic Tuesdays

CHEJ highlights several toxic chemicals and the communities fighting to keep their citizens safe from harm.

Polybrominated Diphenyl Ethers (PBDE)

Polybrominated Diphenyl Ethers (PBDE) are chemicals that are flame retardants – meaning they are added to different materials to make them less susceptible to fires. PBDEs are found in various everyday materials, such as furniture padding, computers, rugs, and electrical wires. They are a synthetic (not naturally found in the environment) subset of the organobromine compounds, chemicals where a carbon molecule is bonded to a bromine molecule. There are 209 different forms of PBDEs, which vary based on what the carbon-bromine structure looks like.

PBDEs were discovered in the 1970s, and since then, several of them have been phased out of production (PentaBDE and OctaBDE), but other versions (such as DecaBDE) are still being manufactured. While some states, such as California and Washington, have banned specific forms of PBDEs from production, there is no national restriction on the production of this chemical as of 2023. It’s also important to note that even for PBDEs that have been banned or phased out of production, the waste from production and manufacturing remains in the environment and causes harm.

The lack of national attention to this class of chemicals is concerning because of the mounting evidence that PBDEs have negative impacts on human health. For example, these chemicals are thought to be endocrine-disrupting. The endocrine system, which oversees the regulation of hormones, is vital to human health. When this system is damaged, it can cause various adverse health effects, such as cancer, reproductive damage, and neurological damage. A case-control study found that exposure to PBDEs was associated with an increased risk of breast cancer among post-menopausal women. Another study found that the BDE-28 compound was associated with an increased risk of papillary thyroid cancer. As for reproductive health, a study on infants reported that pregnancies that had PBDE chemicals in the umbilical cords, those infants were more likely to have lower birth weights. And a chemical that causes fetal abnormalities is called a teratogen, although PBDE does not carry this classification by the Environmental Protection Agency. Evidence of neurological damage has also been in animal studies, where PBDE was found to cause neurotoxic effects on memory, attention, and leaning ability.

Exposure to PBDEs during pregnancy is only one route of exposure to this chemical. Because PBDEs decompose slowly in the environment, they bioaccumulate and build up in the food chain. Fish and other marine life are especially prone to bioaccumulation. Thus, PBDE contamination could be of concern for people who consume a lot of seafood or rely on it as their primary protein source. Another way that people can be exposed to the chemicals is through water. PBDE waste can seep through the ground and contaminate the groundwater sources. Another exposure route, which accounts for an estimated 80% to 90% of exposure for the population, is inhaling contaminated dust particles. For example, PBDE can be found in the dust that accumulates in homes. One study found that individuals who had higher levels of PBDE in the dust at their houses had higher levels of the chemical in their blood serum levels.

PBDEs are considered persistent organic pollutants (POP), and many communities are fighting against this contamination in their backyards. For example, the Alaska Community Action on Toxins (ACAT) has been advocating for years to ban the use of PBDEs in the state. Another group that has been advocating for the ban on PBDEs are first responders, specifically fire-fighter organizations. When blood samples were taken from firefighters, they had brominated dioxins and furans in their bloodstreams. Fire fighters are more exposed to these chemicals because when a house fire occurs, all of the products that have PBDEs in them, such as furniture upholstery, burn up and release these toxic chemicals into the air that the first responders breathe in.

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