Chinese factory workers exposed to high levels of the plastics chemical BPA had low sperm counts, according to the first human study to tie it to poor semen quality.
The study is the latest to raise health questions about bisphenol-A and comes two weeks after Canada published a final order adding the chemical to its list of toxic substances.
Whether the relatively low sperm counts and other signs of poor semen quality translate to reduced fertility is not known. Study author Dr. De-Kun Li, a scientist at the Kaiser Permanente Division of Research in Oakland, Calif., noted that even men with extremely low sperm counts can father children.
But Li said finding that BPA may affect sperm is troubling because it echoes studies in animals and follows his previous research in the same men that linked BPA exposure with sexual problems.
If BPA exposure can reduce sperm levels, "that can't be good" and means more study is needed to check for other harmful effects, Li said.
The study was published online Thursday in the journal Fertility and Sterility. The National Institute of Occupational Safety and Health funded the research.
Andrea Gore, a pharmacology and toxicology professor at the University of Texas who was not involved in the research, called it an important but preliminary study.