PBDEs are widely used flame retardant chemicals that slowly leak out of products and pose threats to human health
PBDEs are used in a wide range of products – including building materials, electronics, fabrics, cars and aeroplanes – because of their flame retardant properties.
They are of concern because they slowly leak out of products and can pose threats to our health.
Animal experiments suggest that this group of chemicals (whose full name is polybrominated diphenyl ethers) can act as endocrine disruptors, meaning they interfere with the body’s hormone system.
They can accumulate in the liver, kidney and thyroid gland, and disrupt important hormones such as oestrogen and thyroid hormones, which affect how the nervous system and brain develop.
Levels of PBDEs in human organs have been increasing in recent years, and are especially high in young children in the United States.
This may be because PBDEs can accumulate in blood and breast milk, and so pose threats to the offspring of people who have been exposed.
Among the commonest products to contain PBDEs are high-impact polystyrene, polyurethane foam, wire and cable insulation, and electrical and electronic connectors. They are often used to make carpets and mattresses flame-resistant.
People who work in places where products containing PDBEs are made, repaired or recycled are at greatest risk of exposure. The chemicals exist in many household products and have been recorded in high concentrations in indoor dust and at waste dumping sites.
Research published in 2009 in the journal Environmental Health Perspectives showed that people in the United States who eat red meat and especially poultry have higher levels of PBDEs in their blood than vegetarians.
This suggests that food is a more important source than previously thought and is likely to be because meat and poultry products come into contact with PBDEs when they are processed and packaged.
Governments have begun to regulate the production and use of PBDEs in recent years. The European Union completely banned two major forms known as Penta and Octa, which are also no longer made in the United States because of health and safety concerns.
In 2009, parties to the Stockholm Convention have agreed to eliminate the two major components of Octa – hexabromodiphenyl ether and heptabromodiphenyl ether.
The commonest PBDEs that are used in electronics are in a form known as Deca, which has been banned in Europe, and in some US states.
Although PBDEs are increasingly being banned, they remain in many old products around the world and will continue to leak out into the wider environment (in household dust for instance) for years to come.
Journalists should take care when reporting on risk as it is not easy to compare the hazards that flame retardant PBDEs pose with the benefits they have brought in saving lives and reducing the costs of fire damage.
Despite this, it is clear for many PBDEs that the risk is high enough to warrant a ban, so journalists can explore whether national and international regulations – such as the Stockholm Convention – are being implemented.
For more localised stories journalists can work with scientists to analyse the PBDE levels in household dust, rubbish dumps, landfill sites and coastal waters to assess whether they are present at dangerous concentrations.
As manufacturers shift to alternative flame retardants, these too may pose unexpected health risks, so journalists can follow the scientific literature to track any possible emerging threats.
A recent study showed, for instance, that men exposed to a new class of organophosphorous flame retardants through household dust had lower thyroid hormone levels and reduced sperm concentration.
For more story ideas and coverage of scientific research into PBDEs, see the Environmental Health News archives.
For journalists reporting on stories related to PDBEs, the IISD Chemicals-L email list is a good source of news and contacts.
CASE STUDY – PBDEs across Asia
Researchers recently studied PBDE levels in a number of Asian countries to see how they compare to those in the West.
They found PDBEs were widespread in marine organisms such as mussels, especially in waters off Hong Kong and South Korea where the PDBE levels were comparable to those in Europe and North America.
Researchers have also found PDBEs in breast milk of women in Cambodia, China, India, Indonesia, Japan, Malaysia, the Philippines, South Korea and Vietnam.
PDBE levels were similar to those found in breast milk in Europe but ten to a hundred times lower than those in North America.
The researchers also found high concentrations of PBDEs in household dust in Japan and in open dumping sites in Cambodia, India and Vietnam.
The researchers warn that as Asian countries rapidly industrialise, more and more PBDEs will be be used there. They call for long-term monitoring to assess the risks to people and the environment. The findings are summarised in this pdf report.
Our Stolen Future – about PBDEs