Saturday, January 16, 2010

Nonstick chemicals linked to infertility

Nonstick chemicals linked to infertility Published in the Science News, copied from Sciencenews.org
Web edition : Tuesday, February 3rd, 2009
A provocative new study finds that women who have trouble getting pregnant are more likely to have high concentrations of certain nonstick-chemical pollutants circulating in their blood than are those who become pregnant within the first month of trying. The suspect compounds — generally known as PFOA and PFOS — are the original primary constituents of Teflon and Scotchguard products.
Since the potential toxicity of certain perfluorinated chemicals began to emerge about a decade ago, formulations of both commercial nonstick-product lines have been reengineered to avoid reliance on PFOA (perfluorooctanoic acid) and PFOS (perfluorooctane sulfonate). Nonetheless, plenty of both compounds still can be found in air, water and the bodies of people throughout the developed world. Indeed, babies are usually born carrying traces of both compounds — and their chemical kin — supplied by their moms’ blood.
Over the past two years, Chunyuan Fei of the University of California, Los Angeles, and her colleagues have linked elevated concentrations of both PFOA and PFOS in mom with a decreased likelihood that her baby or toddler would meet early developmental milestones — such as being able to sit or walk without support or to retrieve something (such as a toy or book) when asked.
In the new study, Fei’s team probes a Danish database of more than 43,000 new moms. From this database they selected 1,240 women who gave birth to a child who was both healthy and “planned” (i.e. not an accident). Then the researchers asked each mom how long she had tried to become pregnant. The number of months it took were then correlated with concentrations of PFOA and PFOS in samples of that woman’s blood during pregnancy.
In an upcoming issue of Human Reproduction, released online January 28, Fei and her coworkers report that “higher maternal PFOA and PFOS levels measured in early pregnancy were found to be associated with longer time to pregnancy.” Indeed, the proportion of women defined as experiencing infertility — meaning it took them more than a year of trying to become pregnant — rose from about 10 percent among women having the lowest concentrations of either perfluorinated pollutant in their blood to roughly twice that rate for moms with the most contaminated blood.
This trend proved true even after accounting for other factors that can affect a woman’s fertility, such as her age, her spouse’s age, sperm quality, and the frequency and timing of sex.
“As far as we know, this is the first study to assess the associations between PFOA and PFOS levels in [blood] plasma and time to pregnancy in humans,” notes team leader Jørn Olsen, who chairs epidemiology at UCLA’s School of Public Health. Concentrations of PFOS ranged from 6.4 to 106.7 nanograms per milliliter of plasma. PFOA levels were lower: from nondetectable to 41.5 ng/ml.
Nor was time to pregnancy the only sign of reproductive perturbation in these women. Notes Fei: “Our data showed that higher proportions of women reported irregular menstrual periods in the upper three quartiles [i.e. 75 percent] of PFOA and PFOS compared with the lowest.”
“These findings are quite alarming,” charges Olga Naidenko, a senior scientist with the Environmental Working Group in Washington, D.C. “The UCLA team’s findings provide important new evidence that drastic declines in fertility rates in both the U.S. and Europe in recent decades may be linked to exposure to toxic chemicals, including PFOA.”
She further argues that the new findings “reinforce the need for strict regulation of PFOA and related chemicals.”
Naidenko is an environmental activist whose organization has been chronicling the emerging toxicology of these largely unregulated perfluorinated compounds in commerce today.
The real travesty is that despite a steady stream of anything-but-reassuring toxicity data on perfluorinated chemicals in recent years, our government still doesn’t know how they’re entering the environment. And Uncle Sam is not doing studies to probe their source, nor is our government aggressively soliciting outside researchers to do that. So how are cautious individuals to gauge ways to avoid these pollutants?
Keep in mind that PFOA and PFOS are not like most other industrial pollutants. They don’t break down. Once released, they just persist. And they’ve been accumulating in the environment — and us — since the 1950s, when these chemicals first started to enter the marketplace in large quantities.
Today, the chemicals are present on nonstick pans and in carpeting, upholstery and clothing that has been treated with stain-guard chemicals. They’ve also been used for years to treat popcorn bags and other packaging that might make contact with grease. Yet tests of these products show minimal release of PFOA and PFOS. Meanwhile, these compounds are showing up in the water entering municipal treatment plants long distances from manufacturing facilities — not to mention in animals and people around the globe.
Let’s not just monitor the accumulating presence of these compounds. Let’s find their sources and limit their continued, apparently uncontrolled releases.
The new study was supported by the International Epidemiology Institute, which received funding from 3M, the maker of Scotchguard. Fei and her colleagues claim 3M had “no control over the design, data analysis and interpretation or writing of this study.”

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