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Over the past couple of
decades, we have started to see an increase in the occurrence of brain
cancer. I've long suspected that much of this increase is due to our
growing exposure to toxic chemicals and pollutants. Now, researchers
from the National Cancer Institute have traced some of the problem to
the long-term consumption of chlorinated water.
I've been warning about the
dangers of drinking chlorinated water for a couple of decades now, and
I'm still shocked that the problem hasn't received more widespread
attention. Every time I see one of these new studies come across my
desk, I'm surprised that one of the major news programs hasn't done an
expose to alert the general public to the dangers of chlorinated
water.
Researchers proved years
ago that most cases of bladder and urinary cancer have direct links to
chlorine and its byproducts in our drinking water. Further studies
have implicated chlorinated drinking water in increased rates of
deadly pancreatic cancer, rectal and colon cancer, and possibly even
breast cancer in women. (Am J Epidemiol 92;136(7):836-42) (Epidemiol
98;9(1}:29-35) (Am J Epidemiol 93;138(7):492-501)
(Cancer Causes Control 97;8(2):192-200)
In this latest study
involving brain cancer, it should come as no surprise that the longer
you drink chlorinated water, the greater your risk of developing
cancer. What was surprising, however, was the fact that the
association between brain cancer and chlorinated water was stronger
among men than women. I don't know why that difference exists, unless
men drink proportionally more water than women. Among men who drank
chlorinated water for 40 or more years, the risk of developing brain
cancer was 2.5 times greater than for those who drank non-chlorinated
water. CAm J Epidemiol 99;150(6):552-60)
Most European countries
have begun to treat drinking water by ozonation and other purification methods instead of
using chlorine. Eventually we will do the
same in this country, but I suspect it will be
decades before that happens. Due to the size of our population, the
enormous Dumber of water systems, and the large areas they must cover,
it would cost trillions of dollars and take a lifetime to change over
our current system. Chlorination is cheap, easy to monitor, and the
simplest way to eliminate bacteria from water. Unfortunately, it is
also steadily increasing the incidence of fatal cancer in this
country.
Science Chlorine Quandary
By Jim Wilson
If civilization as a smell,
it is the cleansing scent of chlorine bleach. It's barely detectable
aroma announces the water is safe, the surroundings are sanitary.
Before the introduction of chlorinated tap water, cholera and typhoid
were as common as the office cold. The protective power of chlorine
resides in its reactivity. It is a bully of a chemical that punches
through the cell walls of bacteria and shatters viruses. And
chlorine's muscle comes cheap. Most of the Earth's surface is covered
with salt water. Zap it with electric current and the sodium and
chlorine atoms go their separate ways. use the chlorine to disinfect a
water supply or to deliver it. Chlorine is also a prime ingredient in
making plastic pipes. Drinking water is just the start. Chlorine based
pesticides civilized the tropics by eradication disease carrying
mosquitoes and timber-chopping termites. Chlorine based refrigerants
put safe refrigerators in our kitchens and air conditioning in our
cars. You would be hard pressed to find any industry that could exist
without at least one chlorine containing chemical. And it is precisely
because of this popularity that a growing number of environmental
scientists and public health experts agree that chlorine should be
banned.
It is slowly becoming clear
that chlorine is a chemical whose time has passed. Persistent organic
pollutants (POP's) threaten the health and well being of humans and
wildlife in every region of the world., sys John Buccini, a Canadian
government representative to the United Nations Environmental Program
(UNEP). After seemingly endless scientific debate, the United Nations
arrived at a list of the 12 most globally threatening POP's. It came
as a surprise to no one who follows environmental had health issues
that each is a chlorine bearing compound, a member of a group of
chemicals known as organoclorines.
In study after study,
exposure to these chemicals has been demonstrated to increase the risk
of cancer and birth defects. They provoke allergic reactions and
damage the nervous, reproductive and immune systems. Some
organochorines mimic the hormone estrogen, thus altering wildlife in
ways that diminish their ability and interest in producing offspring.
Organoclorines are also some of the enduring compounds. Once
introduced into the environment, it can take years, even decades for
POP's to break down to les damaging forms. And if all this were not
reason enough to be cautious, POP's have one final fatal flaw- an
affinity for fat. Our fatty tissue
soaks up POPs like a sponge takes in water. The technical term is
bioconcentratibn. UNEP scientists say that in some animals POPs have
been detected at levels 70,000 times higher than in their
surroundings.
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A
Global Ban
In
December, diplomats from 122 countries met in Johannesburg,
South Africa, to take action. In a series of earlier technical
meetings, POPs had, in effect, been tried and convicted. The
international con- sensu5 was that nature had endured enough
damage. "This new treaty will protect present and future
generations from the cancers, birth defects and other tragedies
caused by POPs," says Buccini, who chaired the session. The
treaty marked a dozen orgall'1cWorines for banishment. Eight are
pesticides. DDT is the most recognizable name. If you are a
farmer or serious gardener, or worry about termites eating your home', you will recognize the others: aldrin, chlordane, dieldrin, endrin, heptachlhlor, mirex and toxaphene
Two of the POPs are industrial chemicals. although one
group,
PCBs, is a household word in many parts of the United States.
For decades. residential streets of America wire lined with
utility poles atop which sat transformers insulated with PCB
fluids. PCBs were used as paint additives and plastics. Unless
your work involves manufacturing fireworks. ammunition or
synthetic rubber, you probably were not aware that the
pesticide hexachIorobenzene is also a highly dangerous
industrial compound. This doesn't mean that you weren't exposed. At one time, the compound circulated widely in the
atmospheric, a byproduct of manufacturing carbon
tetrachloride and similar Cleaning compounds.
Two
unintentionally manufactured families of compounds, dioxins
and furans, complete the list. Colleting of some 210 separate
but similar compounds, they are released in the making of
pesticides, polyvinyl chloride and clorinated solvents. Before
the synthetic chemical industry blossomed in the
1940 " these compounds were chiefly released when waste, coal,
peat or wood was burned.
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The treaty will ban most POP's immediately. Environmentalists are hopeful it will usher in a new
era, a
sort of chlorine sunset in which organochlorines are replaced
by more environmentally benign agents. Ozone, a molecule made of
three, rather than two, oxygen atoms and for this reason highly
reactive, can replace chlorination in
many applications, including drinking and swimming pool water
disinfection and bleaching. The downside is that it is
expensive technology. And, unlike chlorine, ozone quickly
dissipates.
In
several applications, organochlorines are not so easily re-
placed. Chiefly for this reason, the chlorine industry
championed all won health-related exceptions for DDT, to control
malarial mosquitoes. A similar go-slow approach will be taken
with PCBs. Governments will have until 2025 to order companies
to arrange for PCB-free replacements. Neither the environmental
group Greenpeace, which wants a virtually total prohibition on
chlorine chemistry, nor the Chlorine Chemistry Council, an
industry group, which sees the United Nations' brush as
painting too broadly, is entirely happy with the treaty.
But
Klaus Topfer, UNEP's executive director, defends the group's
work. "This is a sound and effective treaty that can be updated
and expanded over the coming decades to maintain the best
possible protection against POPs," he says. For one thing, the
treaty will be liberally sprinkled with special exemptions.
Despite UNEP's sweeping promises, the final wording of the
treaty will contain more than 100 country-specific exemptions.
most to allow longer phase-out times.
But everyone agrees the
treaty is a start. The United Nations will formally sign the treaty at a diplomatic conference in
Stockholm in late
May
of this year. This might seem like the end of a long road for a
treaty that was initially proposed in 1995. but in an important
sense it is only the beginning. Before the POPs ban can take
effect, it must be ratified by 50 of the governments that
participated in the talks last December. If the United
Nations' experiences with similar efforts are a
guide. it could be several years be- fore the treaty takes
effect. IM
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