Featured Research

from universities, journals, and other organizations

New Questions Raised About Controversial Plastics Chemical Bisphenol A

Date:
January 30, 2009
Source:
University of Rochester Medical Center
Summary:
A new study challenges common assumptions about the chemical bisphenol A (BPA), by showing that in some people, surprisingly high levels remain in the body even after fasting for as long as 24 hours. The finding suggests that BPA exposure may come from non-food sources, or that BPA is not rapidly metabolized, or both. Controversy around BPA is mounting.

A University of Rochester Medical Center study challenges common assumptions about the chemical bisphenol A (BPA), by showing that in some people, surprisingly high levels remain in the body even after fasting for as long as 24 hours. The finding suggests that BPA exposure may come from non-food sources, or that BPA is not rapidly metabolized, or both.

The journal Environmental Health Perspectives published the research online January 28, 2009.

Controversy around BPA is mounting. In December the U.S. Food and Drug Administration agreed to reconsider the health risks of the chemical, which is used to make plastic baby bottles, water bottles and many other consumer products. Scientific studies suggest that BPA may harm the brain and prostate glands in developing fetuses and infants; adults with higher BPA levels in their urine were linked to higher risks for heart disease and diabetes, according to a study published last September in the Journal of the American Medical Association.

The latest finding from Rochester is important because, until now, scientists believed that BPA was excreted quickly and that people were exposed to BPA primarily through food. Indeed, the FDA and the European Food Safety Authority have declared BPA safe based, in part, on those assumptions.

"Our results simply do not fit that picture," said lead author Richard W. Stahlhut, M.D., M.P.H., of the University of Rochester's Environmental Health Sciences Center. "The research community has clues that could help explain some of these results but to date the importance of the clues have been underestimated. We must chase them much more vigorously now."

Manufacturers use BPA to harden plastics in many types of products. In addition to plastic bottles, BPA is used in PVC water pipes and food storage containers. BPA also coats the inside of metal food cans, and is used in dental sealants.

Stahlhut and colleagues obtained data for a sample of 1,469 American adults through the Center for Disease Control's National Health and Nutrition Examination Survey (NHANES). The researchers sought to explore the link between BPA urine concentration and the length of time a person had been fasting.

Accepting the widely held assumption that food is the most common route of exposure to BPA, Stahlhut expected to see a relationship between the last food ingested, fasting time, and BPA levels. People who had fasted longest (15 to 24 hours), for example, should have had much lower BPA levels than people who had eaten more recently, Stahlhut said.

Instead, those who fasted had levels that were only moderately lower than people who had just eaten. This is significant because scientists expected BPA levels to decrease by about half, every five hours.

"In our data, BPA levels appear to drop about eight times more slowly than expected – so slowly, in fact, that race and sex together have as big an influence on BPA levels as fasting time," Stahlhut said.

According to the authors, two possible explanations may exist for the higher-than-expected levels of BPA in people who fasted. One is that exposure to BPA might come through other means, such as house dust or tap water.

In addition, Stahlhut theorizes that BPA may seep into fat tissues, where it would be released more slowly. However, further study is needed to evaluate the effects of BPA on adipose tissue hormones and function, Stahlhut said, as well as more studies to compare BPA levels in fat versus blood and urine.

The Centers for Disease Control estimates that 93 percent of Americans have detectable levels of BPA in their urine.

The latest data also supports the idea that individuals might be re-exposed throughout the course of a day, Stahlhut said. In 2000 another research group found that BPA can migrate from PVC pipes or hoses into room temperature water, producing another potential route of exposure.

The University of Rochester School of Medicine and Dentistry, and the National Institute of Environmental Health Sciences Training Grant, funded the research.


Story Source:

The above story is based on materials provided by University of Rochester Medical Center. Note: Materials may be edited for content and length.


Cite This Page:

University of Rochester Medical Center. "New Questions Raised About Controversial Plastics Chemical Bisphenol A." ScienceDaily. ScienceDaily, 30 January 2009. <www.sciencedaily.com/releases/2009/01/090128074926.htm>.
University of Rochester Medical Center. (2009, January 30). New Questions Raised About Controversial Plastics Chemical Bisphenol A. ScienceDaily. Retrieved July 29, 2014 from www.sciencedaily.com/releases/2009/01/090128074926.htm
University of Rochester Medical Center. "New Questions Raised About Controversial Plastics Chemical Bisphenol A." ScienceDaily. www.sciencedaily.com/releases/2009/01/090128074926.htm (accessed July 29, 2014).

Share This




More Health & Medicine News

Tuesday, July 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deadly Ebola Virus Threatens West Africa

Deadly Ebola Virus Threatens West Africa

AP (July 28, 2014) West African nations and international health organizations are working to contain the largest Ebola outbreak in history. It's one of the deadliest diseases known to man, but the CDC says it's unlikely to spread in the U.S. (July 28) Video provided by AP
Powered by NewsLook.com
$15B Deal on Vets' Health Care Reached

$15B Deal on Vets' Health Care Reached

AP (July 28, 2014) A bipartisan deal to improve veterans health care would authorize at least $15 billion in emergency spending to fix a veterans program scandalized by long patient wait times and falsified records. (July 28) Video provided by AP
Powered by NewsLook.com
Two Americans Contract Ebola in Liberia

Two Americans Contract Ebola in Liberia

Reuters - US Online Video (July 28, 2014) Two American aid workers in Liberia test positive for Ebola while working to combat the deadliest outbreak of the virus ever. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Traditional African Dishes Teach Healthy Eating

Traditional African Dishes Teach Healthy Eating

AP (July 28, 2014) Classes are being offered nationwide to encourage African Americans to learn about cooking fresh foods based on traditional African cuisine. The program is trying to combat obesity, heart disease and other ailments often linked to diet. (July 28) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins