High levels of workplace exposure to Bisphenol-A may increase the risk of reduced sexual function in men, according to a Kaiser Permanente study appearing in the journal Human Reproduction, published by Oxford Journals.

The five-year study examined 634 workers in factories in China, comparing workers in BPA manufacturing facilities with a control group of workers in factories where no BPA was present. The study found that the workers in the BPA facilities had quadruple the risk of erectile dysfunction, and seven times more risk of ejaculation difficulty.

This is the first research study to look at the effect of BPA on the male reproductive system in humans. Previous animal studies have shown that BPA has a detrimental effect on male reproductive system in mice and rats.

Funded by the U.S. National Institute of Occupational Safety and Health, this study adds to the body of evidence questioning the safety of BPA, a chemical made in the production of polycarbonated plastics and epoxy resins found in baby bottles, plastic containers, the lining of cans used for food and beverages, and in dental sealants.

The BPA levels experienced by the exposed factory workers in the study were 50 times higher than what the average American male faces in the United States, the researchers said.

“Because the BPA levels in this study were very high, more research needs to be done to see how low a level of BPA exposure may have effects on our reproductive system,” said the study’s lead author. De-Kun Li, MD, Ph.D., a reproductive and perinatal epidemiologist at Kaiser Permanente’s Division of Research in Oakland, Calif. “This study raises the question: Is there a safe level for BPA exposure, and what is that level? More studies like this, which examine the effect of BPA on humans, are critically needed to help establish prevention strategies and regulatory policies.”

The researchers explained that BPA is believed by some to be a highly suspect human endocrine disrupter, likely affecting both male and female reproductive systems. This first epidemiological study of BPA effects on the male reproductive system provides evidence that has been lacking as the U.S. Food and Drug Administration, and various U.S. government panels have explored this controversial topic.

This study is the first of series of studies that examine the BPA effect in humans and are to be published by Dr. Li and his colleagues.

The study finding, Dr. Li also points out, may have implications of adverse BPA effects beyond male sexual dysfunction. Male sexual dysfunction could be a more sensitive early indicator for adverse BPA effects than other disease endpoints that are more difficult to study, such as cancer or metabolic diseases.

For this study, researchers compared 230 workers exposed to high levels of BPA in their jobs as packagers, technical supervisors, laboratory technicians and maintenance workers in one BPA manufacturing facility and three facilities using BPA to manufacture epoxy resin, in several regions near Shanghai, to a control group of 404 workers in the same city from factories where no BPA exposure in the workplace was recorded. The factories with no BPA exposure produced construction materials, water supplies, machinery, garments, textiles, and electronics. The workers from the two groups were matched by age, education, gender, and employment history.

Researchers gauged BPA levels by conducting spot air sampling, personal air sample monitoring and walk-through evaluations, by reviewing factory records and interviewing factory leaders and workers about personal hygiene habits, use of protective equipment, and exposures to other chemicals. A subset of workers also provided urine samples for assaying urine BPA level to confirm the higher BPA exposure level among the workers with occupational BPA exposure.

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 and exposure to other chemicals, and employment history, the researchers found the BPA-exposed workers had a significantly higher risk of sexual dysfunction compared to the unexposed workers.

The BPA-exposed workers had a nearly four-fold increased risk of reduced sexual desire and overall satisfaction with their sex life, greater than four-fold increased risk of erection difficulty, and more than seven-fold increased risk of ejaculation difficulty.

A dose-response relationship was observed with an increasing level of cumulative BPA exposure associated with a higher risk of sexual dysfunction. Furthermore, compared to the unexposed workers, BPA-exposed workers reported significantly higher frequencies of reduced sexual function within one year of employment in the BPA-exposed factories.

Source: Kaiser Permanente

So, it begins. Expect a gradual accumulation of evidence supporting the recommendation made by naturopathic practitioners a very long time ago. Avoid all the toxins you possibly can and cleanse internally as effectively as you can.

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3 Comments to “Bisphenol-A Dose-related Increase in Sexual Dysfunction Risk in Humans”

  1. Editor says:

    The FDA is currently investigating the safety of BPA. It launched its review after coming under intense pressure for basing its original opinion that the substance posed no health threat when used in food packaging on a handful of studies sponsored by the chemical industry. The agency’s science board ordered the re-assessment on the basis that the organisation had failed to consider sufficient research before reaching its conclusion.

    BPA, used in the manufacture of polycarbonate and other plastics, has already been linked to cardiovascular disease and diabetes in humans and disrupted reproductive development in animals. The chemical is commonly found in drinking bottles, baby bottles and sipper cups as well as dentistry composites and sealants and in the lining of aluminum food and beverage cans.

    The FDA was due to release it’s finding on November 30, 2009. Despite providing assurances that the review was on track as recently as mid November the FDA has now indicated that it needs more time to review the scientific literature. Perhaps the industry and the American Chemistry Council are getting to the FDA. They are the ones with money and credibility at stake. Don’t wait for (trust?) the FDA — avoid BPA now.

  2. Editor says:

    Two United Nations bodies are to convene an international meeting on the safety of bisphenol A (BPA) used in food packaging over growing anxiety about the chemical’s possible threat to human health.

    The World Health Organisation (WHO) and the Food and Agriculture Organisation (FAO) said the meeting was being organised in response to the general uncertainty over the safety of BPA. They pin-pointed the misgivings over a raft of possible adverse human health effects from the chemical on reproduction, the nervous system and on behavioural development, as well as the relatively higher exposure of very young children compared with adults. The meeting is scheduled to be held in Canada in October 2010.

    The agencies commented that the large body of research highlighting the toxicity and endocrine activity of BPA in animals, and the discrepancies of study findings relating to the nature of the effects observed and the levels at which they occur, were also major drivers behind calling for the meeting.

    “It is notable that the effects in some of the research studies were described at dose levels several orders of magnitude below those at which effects were reported in the standard guideline (regulatory) studies following OECD test guidelines,” said the WHO.

    Meanwhile, the FDA continues to drag its heels. Despite assurances, no updates on the BPA issue have been forthcoming.

    Don’t wait — avoid BPA now. Demand BPA-free food packaging.

  3. Editor says:

    While the FDA and other authorities around the globe continue to dither, new research on BPA has raised fresh health concerns.

    A study by the French National Institute of Agronomic Research (INRA) found even low doses of BPA caused a negative reaction in the intestine of rats – a commonly used analog for humans in medical research. The report was published in the Proceedings of the National Academy of Sciences. The report focused on the digestive tract as the first organ the chemical comes into contact with after being consumed.

    INRA’s research was also carried out on human intestine cells and revealed the chemical lowered the permeability of the intestines and the immune system’s response to digestive inflammation. In their rat studies they also found that newborn rats exposed to BPA in the uterus and during feeding have a higher risk of developing severe intestinal inflammation in adulthood.

    You would be wise to avoid contamination frim BPA — or further contamination, since you have almost certainly already been exposed to this chemical.

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