Perfluorinated chemicals (PFCs) are back in the news again: a study published in Human Reproduction [pdf] has linked two of them to human fertility problems.
Researchers from UCLA measured levels of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) in blood samples taken from 1,240 pregnant Danish women from 1996-2002. Those with higher levels of the PFCs in their blood had taken longer to become pregnant than those with the lowest levels.
The link is ‘tenuous but interesting,’ according to Tony Rutherford, chairman of the British Fertility Society. As The Times reminds us, correlation does not prove causation.
“There are probably things in the environment that are affecting us in ways we don’t know about, but you have to get to the basic biology of what’s the mechanism of action – that’s the missing link,” Jamie Grifo, director of reproductive endocrinology at New York University Medical Center, tells the Washington Post. “The problem with the study is, it creates more anxiety and fear, but it doesn’t answer [that] question.”
PFCs were thought to be innocuous when introduced in the 1950s. Their stain-repellent and heat-resistant properties have seen them used in fire-fighting foams, food wrappings, pesticides, carpets, upholstery, and as industrial surfactants. But animal studies have sussed them as toxic, potentially carcinogenic, and slow to break down in the environment. Epidemiological studies to check out their danger to humans are ongoing: aside from today’s infertility reports, some have linked them to impaired foetal growth, the researchers say [press release].
Regulators are already phasing out PFCs. The EU enforced a directive heavily restricting the use of PFOS in June 2008, while in May 2009 the Stockholm Convention on Persistent Organic Pollutants is due to make its own decision on restricting or banning PFOS. The US Environmental Protection Agency has got key PFOA-using companies, including DuPont, to agree to cut use of the chemical down by 95% by 2010, and to eliminate it by 2015. But a California bill that would have banned both PFOA and PFOS from food packaging by 2010 was vetoed last year by state governor Arnold Schwarzenegger.
Image: Perfluorooctanesulfonic acid / via wikipedia