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.
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.
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.
2. The US banned PCBs in 1976, when much less was known about PCBs than is known about PBDEs today. But our political situation is far different today than it was in 1976. Corporations today are much more powerful and governments are substantially weaker.