Researchers identified several toxic flame retardants - found in sofas, carpets and other household items - in the urine of American participants.
The research team, led by Robin Dodson of the Silent Spring Institute, says their findings pave the way for further research into how exposure to this class of toxic flame retardants - which are rarely investigated in the US - affect human health.
Flame retardant chemicals are found in a variety of products that we come into contact with every day, such as carpets, sofas, curtains and even baby products. The chemicals were introduced to these products in the 1970s to reduce the likelihood of ignitability.
But over the years, there has been overwhelming evidence that these chemicals may have a negative effect on human health. In 2011, for example, Medical News Today reported on a study suggesting that exposure to flame retardants called polybrominated diphenyl ethers (PBDEs) among pregnant women may affect the brain development of the fetus.
Because of their well-documented toxicity, some flame retardants - such as PBDEs - are now banned from use in the US, although many of us are still exposed to the chemicals in products made prior to such bans.
But Dodson and his team found there is limited information on exposure to phosphate flame retardants (PFRs) in Americans - which are still in use in the US - and how such exposure may impact human health.
Cancer-causing compound found for first time in 75% of participants
To address this lack of information, the researchers analyzed the urine samples of 16 individuals who lived in California in 2011.
By analyzing phosphate biomarkers in the participants' urine - known as dialkyl or diaryl phosphates (DAPs) - the team was able to identify the presence of phosphates in their body. A previous study showed how these DAPs are present in household dust, leading the researchers to investigate whether they are present in urine.
Results of the analysis revealed that all participants had traces of one or more of the following phosphates in their urine: bis-(1,3-dichloro-2-propyl) phosphate (BDCIPP), tris-(1,3-dichloro-isopropyl) phosphate (TDCIPP) and bis-(2-chloroethyl) phosphate (BCEP). All of these are deemed harmful to human health.
"We found that several toxic flame retardants are in people's bodies. When you sit on your couch, you want to relax, not get exposed to chemicals that may cause cancer," says Dodson.
The researchers say they were surprised to find that almost all participants had traces of TDCIPP in their urine, considering that it had stopped being used in children's pajamas in the 1970s due to the potential harm it may pose to human health.
What was more surprising, however, is that they also identified a phosphate in around 75% of participants that has never before been discovered in Americans: tris-(2-chloroethyl) phosphate (TCEP). This chemical is known to cause cancer and reproductive problems in humans.
Although the team's results raise concern, the researchers say they hope it will lead to further studies into the presence of toxic flame retardants in the human body. Co-author Julia Brody, of the Silent Spring Institute, says:
"There has been a breakthrough in that we now know what to look for when trying to figure out if someone has these toxic chemicals in their bodies. This should open up future research on several toxic flame retardants that haven't been scrutinized enough before."
Reducing exposure to toxic flame retardants
Manufacturers are taking note of the potential harm that can be caused by exposure to toxic flame retardants. In California, for example, a recent review of flammability standards has led to the availability of flame retardant-free furniture from January next year.
But there is still a long way to go before human exposure to these chemicals is significantly reduced.
"We have known how toxic these chemicals are for decades and yet they are still being used," says Tony Stefani, president of the San Francisco Firefighters Cancer Prevention Foundation, adding:
"It disturbs me that Californians have cancer-causing flame retardants in their bodies. Another recent study showed San Francisco firefighters had higher flame retardant levels in their blood than the general population of California. We feel that these chemicals are a very large piece of a toxic, complex chemical puzzle we encounter when fighting a fire."
The researchers note that there are strategies consumers can adopt to reduce their exposure to toxic flame retardants. Because the chemicals are likely to gather in dust, they recommend that individuals use a vacuum with a high-efficiency particulate air (HEPA) filter to vacuum their homes. This filter traps particles, rather than recirculate them back into the air.
They also recommend that people throw away any foam that is deteriorating in their households, as it is possible such products may emit higher levels of toxic chemicals.
Last year, MNT reported on a study claiming that phasing out the use of toxic flame retardants in household products is helping to reduce exposure among pregnant women and newborns.