Off Topic - water information

[d rona]

We’ve heard about the BPA problems for a while now, but the newer studies are giving us some sense of just how quickly the chemical enters the body. I’m placing the recent press release in this email. Yet another thing to ask clients about.
Donna
D C Rona, PhD, ND, DHM
_________________________________________
Press Releases

2009 Releases

BPA, Chemical Used to Make Plastics, Found to Leach from Polycarbonate
Drinking Bottles Into Humans

Exposure to BPA May Have Harmful Health Effects

For immediate release: Thursday, May 21, 2009

Boston, MA -- A new study from Harvard School of Public Health (HSPH)
researchers found that participants who drank for a week from polycarbonate
bottles, the popular, hard-plastic drinking bottles and baby bottles, showed
a two-thirds increase in their urine of the chemical bisphenol A (BPA).
Exposure to BPA, used in the manufacture of polycarbonate and other
plastics, has been shown to interfere with reproductive development in
animals and has been linked with cardiovascular disease and diabetes in
humans. The study is the first to show that drinking from polycarbonate
bottles increased the level of urinary BPA, and thus suggests that drinking
containers made with BPA release the chemical into the liquid that people
drink in sufficient amounts to increase the level of BPA excreted in human
urine.

The study appears on the website of the journal Environmental Health
Perspectives and is freely available at
http://www.ehponline.org/members/2009/0 ... 900604.pdf.

In addition to polycarbonate bottles, which are refillable and a popular
container among students, campers and others and are also used as baby
bottles, BPA is also found in dentistry composites and sealants and in the
lining of aluminum food and beverage cans. (In bottles, polycarbonate can be
identified by the recycling number 7.) Numerous studies have shown that it
acts as an endocrine-disruptor in animals, including early onset of sexual
maturation, altered development and tissue organization of the mammary gland
and decreased sperm production in offspring. It may be most harmful in the
stages of early development.

"We found that drinking cold liquids from polycarbonate bottles for just one
week increased urinary BPA levels by more than two-thirds. If you heat those
bottles, as is the case with baby bottles, we would expect the levels to be
considerably higher. This would be of concern since infants may be
particularly susceptible to BPA's endocrine-disrupting potential," said
Karin B. Michels, associate professor of epidemiology at HSPH and Harvard
Medical School and senior author of the study.

The researchers, led by first author Jenny Carwile, a doctoral student in
the department of epidemiology at HSPH, and Michels, recruited Harvard
College students for the study in April 2008. The 77 participants began the
study with a seven-day "washout" phase in which they drank all cold
beverages from stainless steel bottles in order to minimize BPA exposure.
Participants provided urine samples during the washout period. They were
then given two polycarbonate bottles and asked to drink all cold beverages
from the bottles during the next week; urine samples were also provided
during that time.

The results showed that the participants' urinary BPA concentrations
increased 69% after drinking from the polycarbonate bottles. (The study
authors noted that BPA concentrations in the college population were similar
to those reported for the U.S. general population.) Previous studies had
found that BPA could leach from polycarbonate bottles into their contents;
this study is the first to show a corresponding increase in urinary BPA
concentrations in humans.

One of the study's strengths, the authors note, is that the students drank
from the bottles in a normal use setting. Additionally, the students did not
wash their bottles in dishwashers nor put hot liquids in them; heating has
been shown to increase the leaching of BPA from polycarbonate, so BPA levels
might have been higher had students drunk hot liquids from the bottles.

Canada banned the use of BPA in polycarbonate baby bottles in 2008 and some
polycarbonate bottle manufacturers have voluntarily eliminated BPA from
their products. With increasing evidence of the potential harmful effects of
BPA in humans, the authors believe further research is needed on the effect
of BPA on infants and on reproductive disorders and on breast cancer in
adults.

"This study is coming at an important time because many states are deciding
whether to ban the use of BPA in baby bottles and sippy cups. While previous
studies have demonstrated that BPA is linked to adverse health effects, this
study fills in a missing piece of the puzzle-whether or not polycarbonate
plastic bottles are an important contributor to the amount of BPA in the
body," said Carwile.

The study was supported by the Harvard University Center for the Environment
and the National Institute of Environmental Health Sciences Biological
Analysis Core, Department of Environmental Health, HSPH. Carwile was also
supported by the Training Program in Environmental Epidemiology.

"Use of Polycarbonate Bottles and Urinary Bisphenol A Concentrations," Jenny
L. Carwile, Henry T. Luu, Laura S. Bassett, Daniel A. Driscoll, Caterina
Yuan, Jennifer Y. Chang, Xiaoyun Ye, Antonia M. Calafat, Karin B. Michels,
Environmental Health Perspectives, online May 12, 2009.