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[greenyes] More on bisphenol A and polycarbonate
I think I referred to polypropylene in my response about the water bottles
last night. It was quite late when I wrote that and I meant to say
polycarbonate!  I¹m sorry if that confused anyone.

Here¹s more information from Our Stolen Future web site.  If you go to the
site, there are links in the article for additional info:
http://www.ourstolenfuture.org/NewScience/oncompounds/bisphenola/2003/2003-0
413-nalgenebpa.htm    ?

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According to its manufacturer, Nalg Nunc, a popular line of water bottles
sold for hiking and other recreational outdoor uses is made of polycarbonate
plastic (sold as LEXAN).

http://www.nalgene-outdoor.com/technical/materials/index.html

Recent scientific findings link polycarbonate water bottles to chromosomal
aberrations, thus raising questions about the safety of consumer product
made with polycarbonate, especially when they are designed to contain food
or water.

No tests on bisphenol A leaching have been carried out specifically on
Nalgene water bottles, to the knowledge of www.OurstolenFuture.org, nor were
Nalgene bottles the brand used in the experiments demonstrating a link
between polycarbonate and chromosomal aberrations. There may be some reason
why Nalgene bottles do not leach bisphenol A. This would be highly
unexpected, however, given their chemical composition.

The research on chromosome damage, by a team of Case Western Reserve
scientists, found that bisphenol A leaching out of polycarbonate bottles
used to provide water to mice caused a chromosomal error in cell division
called aneuploidy. In humans, aneuploidy is the biggest cause of
miscarriages and birth defects, including Down Syndrome, that has been
identified. In aneuploidy, cells wind up after cell division with the wrong
number of chromosomes. Aneuploidy is thought to be a result of the failure
of chromosomes to align properly during a crucial stage of cell division.
Biphenol A interferes with chromosomal alignment.

The upper, untreated cell has chromosomes aligned properly. The lower cell
has been treated with bisphenol A. Chromosomes are scattered throughout the
cell. They are unlikely to be properly apportioned to daughter cells during
cell division.

The scientists discovered the impact of bisphenol A by accident. A harsh
detergent was used to wash water bottles for the mice in experiments
exploring why aneuploidy becomes more common in older women. This accident
caused an 8-fold increase in the aneuploidy rate in the mice. Subsequent
research confirmed that the cause was bisphenol A leaching out of the
polycarbonate bottles, and that much smaller amounts of the contaminant were
sufficient to increase the rate of chromosomal errors.

Other studies have determined that it doesn't take exposure to harsh
detergents to cause bisphenol A to leach out of polycarbonate. The older the
plastic is, the faster the leaching rate. Heating also increases the amount
of the contaminant that escapes.

These scientific studies have not yet proven with certainty that bisphenol A
causes aneuploidy in people. Yet the process of cell division in mice is
very similar to that in humans, and scientists suspect that the causes of
aneuploidy should be similar if not identical. In addition, a range of
earlier laboratory studies already link bisphenol A to other harmful
effects, including alteration of the male reproductive tract, hurrying
puberty and reducing the effectiveness of prostate tumor treatment.

What is certain is that aneuploidy causes more miscarriages and birth
defects in people than any other known factor. Hence the strong evidence
linking bisphenol A to aneuploidy in mice suggests that measures to reduce
human exposures to this contaminant are now warranted.

In other words, if you have the choice, avoid water bottles made out of
polycarbonate.

The laboratory accident also suggests that if you are compelled to use
polycarbonate water bottles, then at the very least, do not expose them to
harsh chemical conditions. Unfortunately, as of 12 April 2003, that is
precisely what the manufacturer of Nalgene water bottles is recommending for
its products: washing with bleach when staining occurs (see image below).

As noted above, there may be something unique to Nalgene bottles that makes
them chemically different from standard polycarbonate. On the basis of
published information, there is no reason to expect this.
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