Polybrominated diphenyl ether

Polybrominated diphenyl ethers or PBDEs, are compounds used as flame retardants and are added to plastics, polyurethane foam, textiles, and electronic equipment to reduce the likelihood of ignition and to slow the burn rate if the products do catch fire. They can therefore be found in a wide variety of products, eg building materials, cell phones, remote controls, personal computers, computer monitors, motor vehicles, airplanes, plastics, paint products, adhesives, upholstery and textiles. PBDEs are similar in structure to polychlorinated biphenyls (PCBs), and do not break down in the environment.

These substances have ended up in food via the environment, which means that people can ingest them through their food. Since PBDEs are soluble in fat, they are mainly found in animal food products such as fish, shellfish, milk, eggs, meat, oils and fats. They are also found in vegetable oils and fats. Depending on the location and number of bromine atoms, a possible 209 PBDEs can be produced, but as of 2016 only eight were detectable in the environment.

The adverse health effects of these chemicals has attracted increasing scrutiny because levels in the environment and humans have increased rapidly since these chemicals came into use. In animal studies, these chemicals have shown some effects on the thyroid and liver, as well as on brain development. These findings raise particular concerns about potential risks to children and recent studies are suggestive of an effect of PBDEs on neurodevelopment in children, including impaired cognitive development (comprehension, memory), impaired motor skills, increased impulsivity, and decreased attention. One study reported that early PBDE exposure was a risk factor for the development of Attention Deficit Hyperactivity Disorder although another study did not find such a link. One possible explanation for the observed behavioral effects may be related to changes in the thyroid, because development of the nervous system is dependent on thyroid hormones.

Due to their toxicity and persistence in the environment, the industrial production of some PBDEs is restricted under the Stockholm Convention. The Stockholm Convention on Persistent Organic Pollutants, is an international environmental treaty “to protect human health and the environment from chemicals that remain intact in the environment for long periods, become widely distributed geographically, accumulate in the fatty tissue of humans and wildlife, and have harmful impacts on human health or on the environment”. It was first adopted at the United Nations Conference on Persistent Organic Pollutants in Stockholm in 2001. The Convention entered into force on 17 May 2004, ninety days after submission of the fiftieth signature of ratification, acceptance, approval or accession. As of April 2019 182 countries had signed the treaty, although it appears that the USA have yet to ratify it.

Since many older consumer products such as televisions, computers, and furniture containing polyurethane foam contain PBDEs, replacing older products with newer ones that do not contain these substances may decrease PBDE exposure in the home.

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