Non-stick chemicals linked to sperm problems that may affect male fertility.

May 07, 2009

Joensen UN, R Bossi, H Leffers, AA Jensen, NE Skakkebæk and N Jørgensen. 2009. Do perfluoroalkyl compounds impair human semen quality? Environmental Health Perspectives doi:10.1289/ehp.0800517.

Common chemicals that repel stains and water are associated with fewer sperm in Danish men.

Men with high levels of chemicals used as anti-adhesive, stain and water repellents had fewer normal sperms and a tendency for lower sperm concentration.

This study is the first to evaluate the potential impact of exposure to chemicals known as perfluoroalkyl acids (PFAAs) on male fertility. The precise manner through which PFAAs may affect male sperm production is not known. The authors conclude that their preliminary results should be corroborated in larger studies.

PFAAs are a subset of a larger group of chemicals called polyfluorinated compounds (PFCs). The most abundant types–PFOA and PFOS–form when PFCs break down.

The synthetic PFCs are used in a variety of products, including carpets, paper food packaging and clothing. One type is a component of Teflon©, widely used as an anti-adhesive in pots and pans, and another is found in Scotchguard©, which is a popular stain repellent used in clothing, carpets and furniture.

Scientists have only recently realized that these chemicals may leach into the environment and may affect both wildlife and human health.
Exposure to the long-lived chemicals is widespread in people and has been measured in cord blood, suggesting that human fetuses are exposed to PFCs. Prior animal studies reported that PFCs may affect proteins involved in brain development and increase susceptibility to allergens. In humans, exposure to PFCs has been associated with low birth weight.

This new study found that men with high PFAA exposure had a lower mean percentage (6.3 percent versus 8.8 percent) and total number (6.2 millions versus 15.5 millions) of normal sperms compared with men with low exposure. There was also a tendency for a lower sperm count in men with high exposure.

PFAAs measured at the highest concentration included PFOS and PFOA with median concentrations of 25 and 5 nanograms per milliliter, respectively.

Researchers obtained these results after measuring the blood concentration of 10 different PFAAs in 105 Danish men from whom they obtained semen samples.