Is fluoridated water good
for you? Or is it a poison that causes young boys to die
of bone cancer?
For 60 years, U.S. cities and towns have been adding
fluoride to tap water, and for 60 years pro-fluoride
advocates have been unable to forge a scientific consensus
in favor of the practice.
Those who say fluoridation is harmful are often portrayed
as crackpots scanning the heavens for UFOs.
Yet the opponents of fluoridation include a winner of the
Nobel prize in medicine, one of Canada's top dental
researchers, and 11 unions that represent 7,000
environmental and public health professionals at the U.S.
Environmental Protection Agency.
"We have this good science showing this elevated risk of
fatal bone cancer, and nothing's happening in the
regulatory community. It's unconscionable," said William
Hirzy, a union vice president who is a senior scientist in
pollution prevention and toxics at the EPA.
While Massachusetts lawmakers consider a proposal to
mandate water fluoridation throughout the state, the EPA
unions recently called on their agency to classify
fluoride as a carcinogen. They also urged Congress to
declare a moratorium on water fluoridation programs.
Research has tied fluoridated water to bone cancer in
young boys, hip fractures in women, and increased levels
of lead in drinking water. But the biggest challenge for
anti-fluoride lobbyists may be winning the public
relations battle.
"The might of the government is very hard to overcome,"
Hirzy said. "You know how difficult it is for the federal
government to admit they made a mistake....How long did it
take for the public health service to get off endorsing
lead as a great thing in gasoline?"
The EPA declined an interview request to respond to the
union demands, saying the agency is awaiting the results
of a new federal review of fluoride research expected in
February.
The toxic question
More than one-third of Massachusetts cities and towns have
fluoridated drinking water, including all of those served
by the Massachusetts Water Resources Authority.
No one disputes that fluoride, at high enough levels, is
toxic. The chemical has been used as rat poison, and
fluoridated toothpastes must include a warning telling
people to call a poison control center if they swallow
more than used for brushing.
But can tiny amounts of fluoride mixed with drinking water
prevent cavities without causing terrible diseases? This
is the question that has been hotly debated for the past
60 years.
Most European countries have decided that fluoridating
water is too risky. Dr. Arvid Carlsson, a Swedish
pharmacologist who won the 2000 Nobel prize for research
involving the nervous system, argues that some people are
sensitive to the chemical's negative effects even when
exposed at low levels.
"The addition of fluoride to water supplies violates
modern pharmacological principles," Carlsson wrote in the
postscript to journalist Christopher Bryson's recent book,
"The Fluoride Deception."
"Recent research has revealed a sometimes enormous
individual variation in the response to drugs....This
measure is ethically questionable and unnecessarily
expensive."
Studies that tie fluoridated water to bone cancer and
other diseases are dismissed by U.S. government officials
and dental associations, who argue that most researchers
have not found risks associated with fluoride.
"The predominant view of the scientific community is that
there is an optimal range of...fluoride, below which you
don't have the protective effects against tooth decay and
above which you get the detrimental effects," said Howard
Pollick, an American Dental Association spokesman and
dentistry professor at the University of California, San
Francisco.
Holes in evidence?
But even fluoride's intended benefits are up for debate.
The government's official position is that fluoride
improves dental health, and the U.S. Centers for Disease
Control and Prevention has called fluoridating drinking
water one of 10 great public health achievements of the
20th century.
But does it even work? John Bucher, one of the federal
government's top toxicology officials, doesn't think so.
"I don't have any real reason to believe it's dangerous. I
don't have any real reason to believe it's effective,
either," said Bucher, deputy director of the environmental
toxicology program at the U.S. National Institute of
Environmental Health Sciences (NIEHS).
Bucher said fluoride is more effective at preventing
cavities when applied topically, like in toothpaste.
The American Dental Association, a strong supporter of
adding fluoride to public water supplies, says recent
studies show the practice lowers tooth decay rates by 20
percent to 40 percent.
But even the ADA acknowledges that fluoride's effects on
teeth are not all positive. Nearly one in three children
suffer from dental fluorosis, a usually mild condition
that causes discoloration of the teeth and can create pits
on the surface.
"If you were to introduce water fluoridation now, it would
cause more damage to teeth than what it is supposed to
prevent," said Hardy Limeback, a professor at the
University of Toronto and former head of the Canadian
Association for Dental Research.
Limeback was a supporter of fluoridated water before
causing a stir in 1999 when he decided that fluoride
causes more harm than good.
"I wasn't aware of all the toxicology literature. As soon
as I read it, I changed my mind," Limeback said. "It's
contaminated even when you dilute the crude material down
to one part per million (the amount recommended in
drinking water). It still has enough arsenic to increase
the risk for cancer."
Cancer concerns
Pro-fluoride advocates say the cancer risk is overblown,
pointing to the government's National Research Council
1993 review of fluoride studies which found that the legal
fluoride limit of four parts per million in water is
appropriate.
"More than 50 epidemiological studies have examined the
relation between fluoride concentrations in drinking water
and human cancer," the NRC wrote. "These studies provide
no credible evidence for an association between fluoride
in drinking water and the risk of cancer....If there is
any increase in cancer risk due to exposure to fluoride,
it is likely to be small."
This federal report was written three years after the U.S.
Public Health Service found a small increase in
osteosarcoma, a type of bone cancer, in male rats
ingesting sodium fluoride. Bucher, who conducted the
study, said the finding was "equivocal," meaning it is
suggestive of a cancer link but not conclusive.
More evidence connecting fluoride to cancer was found in
2001, by Harvard student Elise Bassin, who earned a
doctorate in medical sciences for a thesis that found boys
in communities with fluoridated water have a significantly
increased risk of developing bone cancer.
Bassin's thesis took center stage in the fluoride debate
when her supervisor, professor Chester Douglass, wrote
that Bassin's work supports his view that fluoridated
water poses no risk even though she found just the
opposite.
Harvard is now investigating an ethics complaint filed
against the professor by the nonprofit Environmental
Working Group, and Bassin's thesis is being reviewed by
the National Research Council as it analyzes new fluoride
research to update its findings issued in 1993. The
updated report, requested by the EPA, is expected in
February.
Bones and poison
There is more than just cancer to worry about when it
comes to fluoride, some researchers have found. Women have
a higher risk of hip fractures when they drink water with
fluoride, according to a 1999 study published in the
American Journal of Epidemiology.
The most commonly used type of fluoride may also increase
the public's exposure to lead. Natick chemist Myron Coplan,
in research conducted with Roger Masters of Dartmouth
College, found that young children in communities that use
a class of fluoride chemicals known as silicofluorides are
about twice as likely to have elevated levels of lead in
their blood.
The finding is supported by new research from the
Environmental Quality Institute at the University of North
Carolina-Asheville, which ran fluoridated water through
pipes made partially of lead for six weeks to determine if
certain combinations cause extra lead to escape the pipes.
The institute found that silicofluorides, combined with
chloramines -- a common disinfectant containing chlorine
and ammonia -- causes a lead level in water at least twice
as high as that in non-fluoridated water, said institute
co-director Richard Maas.
In response to the work of Masters and Coplan, the U.S.
government published an analysis this year that found an
increased lead risk in fluoridated communities of up to 70
percent, but the study's lead author said the difference
was not considered statistically significant because of
the sample size. But he also said the report does not
disprove the lead allegations.
"That's not to say that if a new study were conducted
there might be some association. We certainly encourage
other studies," said lead author Mark Macek of the
University of Maryland.
Silicofluorides, which include the chemicals
hydrofluorosilicic acid and sodium silicofluoride, are
hazardous waste products recovered from the phosphate
fertilizer industry.
Twenty-five years ago, Coplan said, he worked for a
Florida fertilizer company designing equipment to separate
silicofluorides from plants producing phosphate
fertilizer.
"I stood right next to this enormous pond where this toxic
poisonous waste was being collected and eventually shipped
off," Coplan said.
Coplan later argued against fluoridation in Natick, but
the town began using the chemical despite unanimous
opposition from an expert panel formed by town officials
in 1997.
Silicofluorides have never been tested on animals to
determine their toxicity, Bucher and other government
officials acknowledge, but in large enough quantities they
are clearly dangerous.
In February, several blocks of downtown Phoenix, Ariz.,
were closed for 12 hours after a chemical company spilled
nearly 300 gallons of hydrofluorosilicic acid. State
environmental officials fined the company and warned the
public that the fluoride substance is "harmful by
ingestion, inhalation, or skin contact."
Mass. plans
Despite research linking low levels of fluoride in water
to health problems, there are no plans locally to stop
using the chemical. The Massachusetts Water Resources
Authority has fluoridated water since the 1970s, and will
continue to do so as long as the CDC supports
fluoridation, said planning director Stephen Estes-Smargiassi.
"We're not in the business of health research," Estes-Smargiassi
said. "If the CDC changes its mind, you can be assured the
MWRA (will, too)."
William Maas, director of oral health at the CDC, said the
preponderance of evidence proves fluoridated water reduces
tooth decay and doesn't cause harm, and he expects the
National Research Council to reach the same conclusion in
its February report.
"There's no question in my mind that fluoride is good for
us," he said.
The question of whether to add fluoride to water is
usually handled on a town-by-town basis. Many have decided
the risks are too great. But 30 lawmakers in Massachusetts
want to take the choice away from communities by mandating
fluoridation of all water supplies serving at least 5,000
people.
Sen. Pamela Resor, D-Acton, proposed the fluoridation
mandate after listening to a presentation from a group of
public health and dental professionals, she said.
When Resor filed the legislation, she was not even aware
of the research connecting fluoridated water with bone
cancer, increased lead intake and hip fractures. She
didn't learn of these studies until being contacted by a
reporter.
"I will certainly look into all of these," Resor said. "I
certainly don't want to do something that has any of that
kind of detrimental impacts."