The new study, funded by the U.S. National Institute of Occupational Safety and Health, is the first to be designed specifically to test the effects of BPA on humans.
De-Kun Li, the reproductive and perinatal epidemiologist who co-authored this study, said this work confirms that effects found in animal tests also are being seen in humans.
"I would avoid BPA exposure," Li said. "In fact, the less, the better."
The workers were exposed to BPA at levels 50 times higher than the average American consumer faces, the authors of the study noted. Li pointed out that BPA was first developed as an estrogen substitute.
The study comes at a time when there is a push to ban the chemical in food contact items and as the U.S. Food and Drug Administration is reconsidering its earlier finding that BPA is safe for all uses.
The review began after the FDA's own advisory board ruled last year that the agency had not considered the available body of science in its initial ruling. That ruling was based on two studies, both of which were paid for by BPA makers.
Meanwhile, a study last week by Consumer Reports found BPA leaching into the food of nearly all metal cans tested, including those marked "BPA-Free" and "Organic."
Consumer Reports said it got the idea for the tests from a story in the Milwaukee Journal Sentinel, which last year commissioned tests of various baby foods and food storage containers. Those tests found levels in all items tested that proved toxic in animal tests.
BPA, used in the production of polycarbonate plastics and epoxy resins, is commonly found in baby bottles, plastic containers, the lining of cans used for food and beverages, and dental sealants. It has been detected in the urine of 93 percent of Americans tested.
More than 6 billion pounds of BPA are produced each year.
Hundreds of studies on animals over the past decade have linked BPA to neural and behavioral effects and cell damage that has led to breast and testicular cancer.
As part of the new study, researchers measured sexual function based on in-person interviews using a standard male sexual function inventory that measures four categories of male sexual function including erectile function, ejaculation capability, sexual desire and overall satisfaction with sex life.
After adjusting for age, education, marital status, current smoking status, a history of chronic diseases, exposure to other chemicals and employment history, the researchers found the BPA-exposed workers had a significantly higher risk of sexual dysfunction compared with the unexposed workers.
The BPA-exposed workers had a nearly fourfold increased risk of reduced sexual desire and overall satisfaction with their sex life, greater than fourfold increased risk of erection difficulty, and more than sevenfold increased risk of ejaculation difficulty.
John Peterson Myers, a biological scientist whose book "Our Stolen Future" was among the first to raise concerns about chemicals, including BPA, that interfere with the endocrine system, called the study intriguing.
He said the levels of BPA found in the workers were astounding.
"This puts a high flag" on the need for federal agencies to consider the safety of those who work around BPA, he said. "This is a very important study for workers."
BPA manufacturers downplayed the significance of the study, calling it interesting but limited.
Officials from health advocacy organizations calling on the government to ban BPA for use in food contact materials said the new study would bolster their argument.
"This study should serve as a wake-up call to Americans, nearly all of whom have measurable levels of BPA in their bodies," said Elaine Shannon of the Environmental Working Group.
Until now, the focus has been on effects seen in developing fetuses and newborns.
"But there's no reason to believe that adults are somehow exempt from well-documented dangers of BPA or any other chemical that attacks the reproductive system," Shannon said.
Janet Nudelman, policy director of the Breast Cancer Fund, said the study underscores the dangers to those who work around the chemical in huge doses.
"The best way to protect consumers and workers is to stop quibbling over what level constitutes unsafe exposure to BPA and to get this toxic chemical out of food and beverage containers -- our primary source of BPA exposure," Nudelman said.
Canada declared BPA to be toxic and has banned its use in baby bottles.
Similar bans were issued this year in New York's Suffolk County, the city of Chicago, Minnesota and Connecticut. Massachusetts has issued a health advisory for pregnant women and children to avoid products made with BPA.