BPA in our bodies

BPA in our bodies

Postby adminjt » Thu Nov 18, 2010 2:12 pm

Monday, Aug. 16, 2010

Globe and Mail

Statscan survey finds BPA present in 91 per cent of Canadians
First time bisphenol A concentrations were measured nationally; study covered those aged six to 79

by Martin Mittelstaedt

The vast majority of Canadians – more than nine out of 10 – have detectable levels of bisphenol A in their urine, according to the first large-scale survey to track the amount of the estrogen-mimicking chemical in the population.

The results, contained in the Canadian Health Measures Survey conducted by Statistics Canada and released Monday, found that the highest concentration of the chemical, used to make polycarbonate plastic, were in teens aged 12 to 19. Young children aged 6 to 11 also had higher levels than adults aged 40 to 79.

The average level found in the population was 1.16 parts per billion, an exceedingly small amount, but still about a thousand times higher than natural levels of estrogen found in the human body. The survey was conducted nationally from 2007 to 2009.

Exposure to BPA, as the chemical is also known, worries some scientists because cells are not able to distinguish it from naturally occurring estrogen, suggesting that exposures amount to receiving an extra dollop of the female hormone. These researchers are worried the chemical might be behind such trends as earlier puberty in girls, and may cause an increased risk of breast cancer in women and prostate cancer in men, although makers of BPA dispute these claims.

BPA is used to make polycarbonate plastic office-style water jugs, the epoxy resins lining the insides of most tin cans, and is also found in many types of carbonless papers used for such items as cash register receipts, among other uses.

Statscan also released data on lead levels in Canadians, the first time such a survey has been conducted in 30 years. Lead was detected in 100 per cent of the population, but concentrations have fallen dramatically since the late 1970s. Less than 1 per cent of the population was found to have levels of concern in the most recent survey, compared to 27 per cent in 1978/79.

The survey analyzed blood and urine samples for indicators of more than 80 environmental contaminants and chemical substances.

Stats Canada conducted the review of the two substances in conjunction with Health Canada and the Public Health Agency of Canada.

The tests – conducted on more than 5,000 volunteers – amount to one of the largest bio-monitoring surveys ever done in the world.

When people ingest BPA in their food, it is rapidly broken down in hours in the disgestive tract, but Statscan said the high frequency of detection of the chemical “suggest continual widespread exposure in the Canadian population.”

The health implications of the levels of BPA it found are unknown. While Statscan said the chemical “may constitute a health risk, ” it added that there are currently no regulatory standards in Canada for amounts in urine. BPA is made from petroleum and doesn’t normally occur in nature.

But groups concerned with the chemical were quick to say the finding of widespread exposure in Canadians should be a signal to the federal government to take more action to limit the use of the substance.

“The No. 1 priority at the moment has got to be getting it out of the lining of tin cans,” says Rick Smith, executive director of Environmental Defence, an advocacy group. “When nine out of 10 Canadians have a hormonally active chemical in their body, for which easy alternatives are available...why not make some further changes with respect to BPA?”

What is it Bisphenol A?

Bisphenol A is a man-made chemical that is used in such everyday products as polycarbonate plastic water jugs, the epoxy resins lining the insides of tin cans and some types of carbonless cash-register receipts.

What does it do?

Bisphenol A is able to mimic estrogen, which raises concern that exposure amounts to an extra dose of the female hormone.

Although the amounts in canned foods and drinks are minuscule – typically only a few parts per billion – they are still about 1,000 times the natural concentration of estrogen in humans.

Elevated exposure to bisphenol A, which is also known as BPA, has been linked to an increased risk of cardiovascular disease and adult-onset diabetes in humans.

Research in laboratory animals has associated BPA with such conditions as breast cancer, earlier sexual maturity in females and altered brain development, especially for exposures that occur during fetal or early neonatal life.

What has the government done?

In 2008, the federal government announced it would designate BPA as a toxic compound. It was removed from plastic baby bottles as a safety precaution, but is still used as a liner inside almost all food and beverage cans sold in Canada.

With files from CP

ARCADIA, CA - APRIL 16: Camelback brand water bottles that are free of the controversial carbonate plastic bisphenol a (BPA), one of the most widely used synthetic chemicals in industry. 2008 Getty Images/ David McNew

See also:

* Workplace BPA tied to male sex problems
* Bisphenol A: Elevated amount of BPA can increase cardiac risk by 45%, study finds
* Food may not be sole BPA source

http://www.theglobeandmail.com/life/hea ... le1674153/

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Monday, August 16, 2010

CBC News

BPA contaminants found in most Canadians

About 91 per cent of Canadians have detectable levels of bisphenol A (BPA), a chemical used to make some hard plastic containers, bottles and toys, a new report suggests.

Statistics Canada released the finding Monday as part of the results of its survey measuring the levels of various contaminants in the urine of Canadians aged six to 79.
What is bisphenol A?

Bisphenol A is a chemical compound found in some hard, clear, lightweight plastics and resins. It's used in the production of various types of food and drink containers, compact discs, electronics and automobile parts, and as a liner in some metal cans. Animal studies suggest that, once ingested, BPA may imitate estrogen and other hormones, according to the National Institutes of Health.

Bisphenol A is an industrial chemical used to make polycarbonate plastic for water bottles and food containers as well as the protective lining in metal cans. It does not occur naturally in the environment.

Some studies on animals suggest that low levels of exposure to BPA very early in life can affect brain development and behaviour, but scientists are unsure in interpreting how these findings might be relevant to human health, Statistics Canada said.

Animal studies suggest that, once ingested, BPA may imitate estrogen and other hormones, according to the U.S. National Institutes of Health.

Compared with children aged six to 11, those aged 12 to 19 had a higher concentration, while those aged 40 to 79 had lower concentrations, Statistics Canada said.

It is the first time the BPA levels of Canadians have been measured in a nationally representative sample of the population.

The findings are consistent with results from international studies, the agency said. BPA has been detected in 93 per cent of Americans aged six or older, and 99 per cent of Germans aged three to 14.

The Statistics Canada data "suggest continual widespread exposure in the Canadian population," the report concluded.

Canadians' average BPA level in their urine was 1.16 micrograms per litre.

In October 2008, Canada became the first country in the world to ban the import and sale of polycarbonate baby bottles containing bisphenol A, as a safety precaution. It is still used as a liner in food and beverage cans sold in Canada.

Future surveys will allow Health Canada scientists to better assess whether Canadians' exposure to environmental chemicals is changing, Health Minister Leona Aglukkaq said in a release.

Related: Canadians' lead levels show dramatic drop

While there is still uncertainty about the health risk of BPA, it is excreted quickly and the fact that it was not found in some participants is good news, professor Linda Campbell, an environmental expert on mercury and metals at Queen's University in Kingston, Ont., said in an email.

"The BPA concentrations are of concern at the higher concentrations, but since it is not persistent in humans, we should be able to see an immediate reduction if we can limit this compound," added Campbell, Canada Research Chair in aquatic ecosystem health.

Campbell said she supports the precautionary principle of not mass producing new chemicals until scientists know whether they are safe for humans and the environment. She also supports government efforts to rapidly reduce BPA in food and drink.

The survey also looked at Canadians' levels of lead and mercury contamination.

Samples for the study were collected from March 2007 to February 2009 from a representative sample of about 5,600 Canadians aged six to 79 years at 15 sites across the country.

http://www.cbc.ca/health/story/2010/08/ ... z0wn2gBoAp

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