More and more Australian babies and young children are exposed to toxic flame-retardant chemicals emanating from cheap imported carpets, furniture, foam mattresses and electronic goods, a new scientific study indicates.
Research at the CRC for Contamination Assessment and Remediation of the Environment (CRC CARE) shows that levels of bromine-based flame-retardant chemicals known as PBDEs may be rising in the Australian indoor environment, and that children are the group most exposed.
Dust samples from 22 out of 29 Adelaide homes were found to contain various PBDEs, at levels mostly significantly higher than in a study carried out in Brisbane in 2008. Analysis showed the chemicals came from furniture and electronic items.
"Our results suggest that the levels of PBDEs in the Australian indoor environment are slowly increasing even though they are not produced in this country," explains Devarajan Shanmuganathan, a doctoral researcher with CRC CARE and the University of South Australia.
"Houses containing polyurethane foam products, synthetic carpets and plastic products pose significant risk to children. House dust increases the exposure of very young children to PBDEs, beyond what they are already receiving through breast milk and other food. Infants are particularly exposed because of the time they spend playing on the carpet."
The managing director of CRC CARE, Professor Ravi Naidu, says that the significance of the research has been highlighted by a recent decision to ban several PBDEs under the Stockholm Convention as 'persistent organic pollutants'. Europe has already decided to phase out their use.
"Australia does not produce PBDEs and we import very little for our own manufacturing. However this research indicates that Australians, especially children, are being increasingly exposed to these contaminants through imported furnishings, electronic goods and food - and this is an issue we need to pay attention to."
PBDEs (polybrominated diphenyl ethers) have been used worldwide for more than 30 years to reduce the fire-risk in plastic-based products and furnishings. They are totally synthetic substances that do not occur in nature. They are highly persistent in the environment and magnify along the food chain: levels found in both humans and wildlife have been doubling globally every five years, Prof. Naidu says.
As a consequence, research around the world - including Australia - detected high levels of PBDEs in human breast milk, making infants the most exposed of all groups, Prof. Naidu says.
"In babies and young children these chemicals can interfere with thyroid function, with the growth of the central nervous system and with reproductive development - and are clearly undesirable in either the home or the food chain.
"They are now quite commonly found in foods such as fish, meat and dairy products. Because these chemicals are so persistent and do not break down easily in the environment, they build up and concentrate in the food chain, which means that we humans tend to receive a bigger dose when we consume livestock products," Prof. Naidu says.
The CRC CARE research found PBDEs in soil samples taken from residential, recreational and waste disposal sites in Adelaide, though these were generally low by world standards, and significantly higher levels from industrial sites involved in plastics manufacturing or recycling.
The research has identified several biological and physical methods with potential for breaking down PBDEs in contaminated soil, but all require further research.