Male factory workers in China exposed to high levels of bisphenol A dust in the workplace have a significantly higher risk of sexual dysfunction than the general population, according to a new study.
The findings raise warning signs for workers exposed to BPA dust, but not for people with typical low-level BPA exposure, said a study published Nov. 10 in the journal Human Reproduction.
The findings from this study probably do not apply to populations that are exposed to low levels of BPA, the study said. The observation association [between BPA and sexual dysfunction] may only apply to highly exposed workers. A similar effect [from lower doses] remains unclear.
The most common workplace exposure to BPA dust is in the manufacture of epoxy resins, said Steve Hentges, executive director of the polycarbonate/BPA global group of the American Chemistry Council in Arlington, Va. There is limited exposure to BPA dust in the manufacture of polycarbonate because BPA is used in an enclosed process, he said.
Hentges said it is less clear whether the study has relevance for workers in the United States, because the study did not look at whether the workers used personal protective equipment such as respirators, dust masks or gloves. There was no substantiation of whether they were used, he said in a Nov. 13 interview.
It is questionable whether those levels of exposure would occur when proper protective equipment is used. It is essential that employees wear personal protective equipment appropriate to their environment, he said.
In addition, the conclusions of the five-year study by the Kaiser Foundation Research Institute were based on information self-reported by 634 workers in one BPA and three epoxy resin plants, as there were no medical or clinical examinations of either the workers or control group.
That's a shortcoming the study admits. One may argue that [information about] self-reported sexual function may contain inaccuracies, it said. In addition, the researchers said we did not collect information on stress which could possibly impact self-reported sexual dysfunction.
Still, researchers said findings represent the first piece of evidence that exposure to BPA may have an adverse effect on male sexual functioning in the human population. But they underscored that exposure levels of the workers studied were much higher than that of the non-occupationally exposed general population.
Based on urine samples, the median level of BPA in the 634 manufacturing workers was 57.9 micrograms per gram of creatinine compared with 1.2 micrograms in the control group, which is the amount typically found in the general population.
The study has limited relevance to the general population because consumer exposure is through diet, Hentges said. The general population can never run into BPA as a pure chemical in a consumer product, but can only encounter trace levels.
There is very limited potential for dermal exposure or to inhale it as a consumer.
A number of laboratory studies have linked BPA to birth defects, low birth weights, cancer, early puberty and other health problems in rats. However, 11 safety agencies around the world have said that BPA is safe for use in food-contact applications.
Copyright 2009 Crain Communications Inc. All Rights Reserved.