Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Exposure to BPA associated with reduced semen quality

28.10.2010
Increasing urine BPA (Bisphenol-A) level was significantly associated with decreased sperm concentration, decreased total sperm count, decreased sperm vitality and decreased sperm motility, according to a Kaiser Permanente study appearing in the journal of Fertility and Sterility.

The five-year study recruited 514 workers in factories in China and compared workers who had high urine BPA levels with those with low urine BPA. Men with higher urine BPA levels had 2-4 times the risk of having poor semen quality, including low sperm concentration, low sperm vitality and motility.

This is the first human study to report an adverse association between BPA and semen quality. Previous animal studies found a detrimental association between BPA and male reproductive systems in mice and rats.

This study is the third in a series, published by Dr. Li and his colleagues, that examine the effect of BPA in humans. The first study, published in November 2009 in the Oxford Journals Human Reproduction, found that exposure to high levels of BPA in the workplace increases the risk of reduced sexual function in men. The second study, published in May 2010 in the Journal of Andrology, found that increasing BPA levels in urine are associated with worsening male sexual function.

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

"Compared with men without detectable urine BPA, those with detectable urine BPA had more than three times the risk of lowered sperm concentration and lower sperm vitality, more than four times the risk of a lower sperm count, and more than twice the risk of lower sperm motility," said the study's lead author. De-Kun Li, MD, PhD, a reproductive and perinatal epidemiologist at Kaiser Permanente's Division of Research in Oakland, Calif. He added that urine BPA was not associated with semen volume or abnormal sperm morphology.

"Similar dose-response associations were observed among participants with only environmental BPA exposure at levels comparable to men in the general United States population," said Li.

Despite a markedly reduced sample size in this group of men exposed only to low environmental BPA sources, the inverse correlation between increased urine BPA level and decreased sperm concentration and total sperm count remain statistically significant, the researchers explained.

"The consistency of the findings between the current and the previous two studies, despite different exposure measurements (urine BPA levels vs. BPA exposure in the workplace) and end points (semen quality vs. sexual function), strengthens the validity of these findings," said Dr. Li. "The finding of the adverse BPA effect on semen quality illustrates two points: first, exposure to BPA now has been linked to changes in semen quality, an objective physiological measure. Second, this association shows BPA potential potency: it could lead to pathological changes of the male reproductive system in addition to the changes of sexual function."

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 new epidemiological study of BPA's effects on the male reproductive system provides evidence that has been lacking as the U.S. Food and Drug Administration and various other U.S. government panels have explored this controversial topic.

These findings, Dr. Li also points out, may portend adverse BPA effects beyond the male reproductive system. Semen quality and malesexual dysfunction could be more sensitive early indicators for adverse BPA effects than other disease endpoints that are more difficult to study, such as cancer or metabolic diseases.

For this study, workers in participating factories with and without BPA exposure in the workplace were identified and deemed eligible for the study. Among 888 eligible workers, 514 (58 percent) agreed to participate in the study. Of them, 218 participants provided both urine and semen specimens and were included in the final analyses. Through an in-person interview, participants provided information on demographic characteristics; potential risk factors that may influence semen quality including smoking, alcohol use, chronic diseases, history of sub-fertility, exposure to other chemicals and heavy metals; and recent exposure to heat sources such as a steam bath, as well as occupational history.

Other authors on this study include: J.R. Ferber, MPH, and L.J. Herrinton of the Kaiser Permanente Division of Research; Z. Zhou, PhD, MD, and Y. He, PhD, of the Department of Occupational Health and Toxicology, School of Public Health and WHO Collaborating Center for Occupational Health, Fudan University, Shanghai, China; M. Miao, PhD, J. Wang, PhD, E. Gao, MD, MPH, PhD, and W. Yuan of Shanghai Institute of Planned Parenthood Research and National Population and Family Planning Key Laboratory of Contraceptive Drugs and Devices.

About the Kaiser Permanente Division of Research (http://www.dor.kaiser.org/)

The Kaiser Permanente Division of Research conducts, publishes and disseminates epidemiologic and health services research to improve the health and medical care of Kaiser Permanente members and the society at large. It seeks to understand the determinants of illness and well-being and to improve the quality and cost-effectiveness of health care. Currently, DOR's 400-plus staff is working on more than 250 epidemiological and health services research projects.

About Kaiser Permanente

Kaiser Permanente is committed to helping shape the future of health care. We are recognized as one of America's leading health care providers and not-for-profit health plans. Founded in 1945, our mission is to provide high-quality, affordable health care services to improve the health of our members and the communities we serve. We currently serve 8.6 million members in nine states and the District of Columbia. Care for members and patients is focused on their total health and guided by their personal physicians, specialists and team of caregivers. Our expert and caring medical teams are empowered and supported by industry-leading technology advances and tools for health promotion, disease prevention, state-of-the art care delivery and world-class chronic disease management. Kaiser Permanente is dedicated to care innovations, clinical research, health education and the support of community health. For more information, go to: www.kp.org/newscenter.

Danielle Cass | EurekAlert!
Further information:
http://www.kaiserpermanente.org

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Storage & Transport of highly volatile Gases made safer & cheaper by the use of “Kinetic Trapping"

Augsburg chemists present a new technology for compressing, storing and transporting highly volatile gases in porous frameworks/New prospects for gas-powered vehicles

Storage of highly volatile gases has always been a major technological challenge, not least for use in the automotive sector, for, for example, methane or...

Im Focus: Disrupting crystalline order to restore superfluidity

When we put water in a freezer, water molecules crystallize and form ice. This change from one phase of matter to another is called a phase transition. While this transition, and countless others that occur in nature, typically takes place at the same fixed conditions, such as the freezing point, one can ask how it can be influenced in a controlled way.

We are all familiar with such control of the freezing transition, as it is an essential ingredient in the art of making a sorbet or a slushy. To make a cold...

Im Focus: Micro energy harvesters for the Internet of Things

Fraunhofer IWS Dresden scientists print electronic layers with polymer ink

Thin organic layers provide machines and equipment with new functions. They enable, for example, tiny energy recuperators. In future, these will be installed...

Im Focus: Dynamik einzelner Proteine

Neue Messmethode erlaubt es Forschenden, die Bewegung von Molekülen lange und genau zu verfolgen

Das Zusammenspiel aus Struktur und Dynamik bestimmt die Funktion von Proteinen, den molekularen Werkzeugen der Zelle. Durch Fortschritte in der...

Im Focus: Dynamics of individual proteins

New measurement method allows researchers to precisely follow the movement of individual molecules over long periods of time

The function of proteins – the molecular tools of the cell – is governed by the interplay of their structure and dynamics. Advances in electron microscopy have...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

5th International Conference on Cellular Materials (CellMAT), Scientific Programme online

02.10.2018 | Event News

Major Project: The New Silk Road

01.10.2018 | Event News

"Boston calling": TU Berlin and the Weizenbaum Institute organize a conference in USA

21.09.2018 | Event News

 
Latest News

Physics: Not everything is where it seems to be

15.10.2018 | Physics and Astronomy

Microfluidic molecular exchanger helps control therapeutic cell manufacturing

15.10.2018 | Life Sciences

Link between Gut Flora and Multiple Sclerosis Discovered

15.10.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>