The possible health risks of plastics have been in the news quite a
bit in recent years. One of the greatest controversies centers on the
safety of polycarbonate plastics, which are often used in the
manufacture of water bottles, baby bottles, and food containers. One
component of polycarbonate plastics, bisphenol A (also known as BPA),
is of particular concern.
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"Bisphenol-A is building block of polycarbonate plastic, a hard
plastic used to make numerous consumer products, including most baby
bottles and 5-gallon water bottles. Bisphenol-A is also used in epoxy
resins, in the plastic lining of some food cans, in some dental
sealants, and as an additive in other consumer products...
Health Effects:
Damage to male reproductive organs in test animals: Male laboratory
animals exposed to low levels of bisphenol-A in the womb had enlarged
prostate weight as adults, shrunken epididymides (sperm-carrying
ducts), and reduced sperm counts.
Early puberty and 20% increase in body weight in female laboratory
mice exposed to bisphenol-A in the womb, and increased body weight in
mice of both genders exposed as embryos."
Children's Health Environmental Coalition
http://www.checnet.org/healthehouse/chemicals/chemicals-detail.asp?Main_ID=275
"Environmental exposure to a widespread compound used to make common
plastic food containers and baby bottles and to line tin cans
interferes with cell division in the eggs of female mice, according to
research. If cell division is disturbed, it can result in aneuploidy,
or an abnormal number of chromosomes in the eggs. This condition is
the leading cause of mental retardation and birth defects in humans,
including Down syndrome.
Even extremely low levels of the compound, called Bisphenol A (BPA),
produced genetic abnormalities, according to researchers. BPA exhibits
hormone-like properties and imitates the effects of naturally
occurring estrogens...
Bisphenol A (BPA) was invented in the 1930s during the search for
synthetic estrogens. The substance is now deeply imbedded in the
products of modern consumer society, not just as the building block
for polycarbonate plastic (from which it then leaches as the plastic
ages) but also in the manufacture of epoxy resins and other plastics,
including polysulfone, alkylphenolic, polyalylate, polyester-styrene,
and certain polyester resins.
This is one of the major reasons why you will want to store your food
and water in glass if at all possible. Plastics are far more likely to
contribute dangerous types of chemicals to the contents."
Dr. Joseph Mercola
http://www.mercola.com/2003/apr/16/food_storage.htm
A simple way to determine whether a bottle or food container is made
of polycarbonate is to look at the recycling code on the bottom of the
container. If the recycling code is #7, this indicates polycarbonate
plastics. To avoid polycarbonates, choose containers made of glass or
polyethylene (#1, #2, #4 recycling codes), or polypropylene (#5).
More information about bisphenol-A is available here:
Google News Search: "bisphenol-a"
http://news.google.com/news?hl=en&edition=usa&q=%22bisphenol-A
For a different view, here you will find information provided by the
plastics industry:
Bisphenol-A Home Page
http://www.bisphenol-a.org/index2c.html?
More information about bottled water:
Save America's Water
http://www.saveamericaswater.com/aboutcos.html
A good article about other plastics used in food packaging:
Ecology Center
http://www.ecologycenter.org/iptf/toxicity/mothersandothers.html
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Regarding the matter of whether to choose bottled water or San
Francisco tap water, you're certainly correct about the poor quality
of SF's water:
"San Francisco earned a water quality and compliance grade of Poor for
2000 and 2001. Factors in this grade included the following:
Although San Francisco's source water is generally very well
protected, the city had high levels of cancer-causing contaminants
called total trihalomethanes, or TTHMs, by-products of the heavy use
of chlorine for disinfection of its tap water. San Francisco is one of
the few large cities in the United States with TTHM levels still in
excess of a new EPA tap water standard that went into effect in
January 2002. San Francisco also has potentially dangerous high spikes
in the levels of these chemicals in its tap water. The city applied
for and received a two-year extension from the EPA for bringing the
system into compliance with this standard. The San Francisco Public
Utilities Commission (SFPUC) should not have allowed this problem to
continue into 2002. The city says it is taking steps to reduce its
TTHM levels by 2003, but its solution, a switch to chloramine
disinfection, is a half-measure that will only moderately reduce TTHM
levels and will not kill chlorine-resistant microbes.
In addition, San Francisco's water in 2000 and 2001 raised other
concerns:
Cryptosporidium and Giardia, waterborne microbes that can present
human health concerns, particularly for individuals with weakened
immune systems, were found at low levels in San Francisco's treated
tap water. The presence of these pathogens even at fairly low levels
is of some concern. That is particularly the case because the city
does not filter its Hetch Hetchy water supply, and this unfiltered
water occasionally had spikes in turbidity levels (cloudiness in the
water that can indicate the presence of pathogens) of up to 0.76
nephelometric turbidity units (NTU) in 2001. Unfiltered water has a
standard of 5 NTU and filtered water a standard of 1 NTU, so while the
turbidity of this water supply does not violate EPA standards, it
bears continued careful scrutiny. Installation of advanced alternative
disinfection to kill chlorine-resistant pathogens like Crypto is
recommended, and would reduce TTHM levels as well. Lead levels were
found in excess of the EPA health goal. In 2001, lead levels at 4 of
53 tested residences (8 percent) were over the EPA action level. The
EPA allows up to 10 percent of tap water to exceed the action level,
so the city was not in violation. But San Francisco's lead problem is
a concern for children and pregnant women who drink from taps
containing excessive lead."
National Resources Defense Council
http://www2.nrdc.org/water/drinking/uscities/sf.pdf
NOTE: The file linked above is in .pdf format. You need to have Adobe
Acrobat Reader software installed on your computer in order to view
.pdf files. If you do not already have this software, a free download
is available here:
Adobe Acrobat Reader
http://www.adobe.com/products/acrobat/readstep2.html
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If I were in the position of choosing whether to drink bottled water
or San Francisco tap water, I believe I would choose the latter, with
an important addition: a water filter. Filtered water not only tastes
better than raw tap water, but it is relatively free of contaminants
such as trichloromethanes, lead, arsenic, pesticides, and certain
micro-organisms.
Most of the online sites which offer material about water filters are
trying to sell a particular brand of filter. Some of these sites seem
to slant the information in such a way as to make their product seem
unique, or better than all the rest. Here is a good, general, unbiased
description of the different types of water filters that are
available:
Water Filter Info
http://www.water-filter-gpm.com/
Personally, I would choose a carbon block filter. It is relatively
inexpensive to use, and is quite effective in removing many
contaminants. Obviously, one is not always at home when the need for a
drink of water arises; when on the go, I believe I would choose
bottled water (preferably in a glass container, or in
non-polycarbonate plastic, as indicated by the recycling code on the
bottom of the bottle) over San Francisco's tap water, at least until
the city has dealt with the problem of the trichloromethanes.
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Search terms used:
"water bottles" + "safety"
"water bottles" + "hazard(s)"
"water bottles" + "health"
"plastics" + "safety"
"plastics" + "hazard(s)"
"plastics" + "health"
"polycarbonate"
"bisphenol-a"
"bpa"
"tap water" + "san francisco"
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I hope this information is helpful. If anything I've said is not
clear, or if a link does not function, please request clarification;
I'll be glad to offer further assistance before you rate my answer.
Best regards,
pinkfreud |
