Brominated flame retardants

All brominated fire retardants seem capable of creating environment and health problems. The class called polybromodiphenyl ethers (PBDEs) are some of the most commonly used: in the plastics in appliances, TVs and computers, foam in upholstery and the fabrics of carpets and draperies. Many hard styrene plastics and many foam padding materials are 5% to 30% PBDE by weight. PBDEs can volatilize (ooze into the air) out of electrical components, especially from warm devices such as computers and TV sets. Other major sources of PBDEs are thought to be municipal incinerators and landfills.

PBDEs are not very soluble in water, but they dissolve readily in fat. They are also persistent in the environment (meaning they break down only slowly). As they move through the food chain, they concentrate and biomagnify (like their cousins polychlorinated biphenyls (PCBs)). Certain forms cause cancer, interfere with hormones and disrupt normal growth and development in laboratory animals. They can interfere with the thyroid hormone, which is critical for the proper development of the brain and central nervous system in animals and humans. Baby mice exposed to PBDEs show permanent behavioural and memory problems, which worsen with age.

Worldwide, eight chemical corporations manufacture about 135 million kg of brominated fire retardants each year, of which about 36 million kg are polybromodiphenyl ethers (PBDEs).

In 1999, the Swedish Chemicals Inspectorate concluded that the lower-brominated technical PBDE compounds, containing mostly penta-BDE, are persistent, bioaccumulative and toxic in the aquatic environment. They show effects above all on the liver but also on thyroid hormone and affect the behaviour of mice. They occur widely in the environment, in human blood and in mother's milk.

European researchers have found Polybromodiphenyl ethers (PBDEs) in freshwater and ocean fish (salmon, herring, sprat), in air at remote rural locations, in sewage sludge, in deep ocean sediments, in eels, seals, shellfish, bottlenose dolphins, porpoises, pilot whales and crabs, among other species. Studies in Germany, Holland, Sweden, Japan and the USA have reported the presence of PBDEs in fish, meat, cow's milk, fats and oils and bakery products. Studies of human blood in the USA have revealed PBDEs in all samples. The Great Lakes of the USA and Canada appear to be among the most PBDE-contaminated bodies of water in the world, with Lake Michigan the worst.

PBDE levels have been increasing exponentially in the environment in Sweden for 30 years and show no sign of levelling off. They have been increasing exponentially in breast milk in Sweden since 1972, the concentration doubling every 5 years. Current levels in breast milk and in the Swedish diet are considered by experts to be far below the levels known to harm laboratory animals, but they warn that the time trend of PBDEs in human breast milk is alarming for the future. No one knows for sure what the effects of PBDEs might be on developing embryos or suckling infants. Sweden, Denmark and the Netherlands has taken precautionary action to remove such chemicals from the market. The European Parliament voted in September 2001 to ban the use, manufacture, and import of some forms of PBDEs during the next few years, but the European Council of Ministers must approve the ban before it becomes law.

The dust at the site of the World Trade Center atrocities resulted from thousands of plastic computers, tens of thousands of square metres of flammable carpet and tonnes of office furniture pulverized when the twin towers and other nearby buildings collapsed September 11. To make matters worse, a portion of this high-tech dust is being continuously incinerated by a stubborn fire smoldering beneath the rubble. In several "risk assessments" of air pollution hazards at "ground zero", US Environmental Protection Agency (EPA) concluded that the air in lower Manhattan is safe for workers and residents, but EPA's risk assessment did not consider PBDEs (nor did it consider many other chemicals probably present in that air). Notably, in spite of EPA's assurances of safety, more than 4000 people have developed chronic chest pain, a persistent cough now known as "world trade center cough" and asthma-like (or emphysema-like) breathing problems from exposure to the air in lower Manhattan.