Cancer and Fluoride from FAN
Cancer and Fluoride from FAN
"We observed that for males diagnosed before the age of
20 years, fluoride level in drinking water during growth was associated with an
increased risk of osteosarcoma, demonstrating a peak in the odds ratios from 6
to 8 years of age. All of our models were remarkably robust in showing this
effect, which coincides with the mid-childhood growth spurt." (Bassin, et
al., Cancer, Causes & Control, 2006)
Cancer
According to the National Toxicology Program (NTP), “the
preponderance of evidence” from
laboratory studies indicates that fluoride is a mutagen (a
compound that can cause genetic damage). A chemical that can cause genetic
damage is one that can likely cause, or contribute to, the development of
cancer.
While the concentrations of fluoride causing genetic damage in laboratory
studies are generally far higher than the concentrations found in human
blood, there are certain “microenvironments” in the body (e.g., the bones,
bladder, kidneys, oral cavity, pineal gland) where cells can be exposed to
fluoride levels that are comparable to those causing genetic damage in the
laboratory. Moreover, some research has found that cells of primates (including
great apes and humans) are more susceptible to fluoride’s mutagenic effects
than cells of rodents. These factors may help explain why seven
studies since the 1990s have found evidence of genetic damage in
humans with high fluoride exposures. (Some studies have not found this
association.)
Fluoride & Osteosarcoma (Bone Cancer)
The concern that fluoride can cause cancer has been fueled
by evidence linking it to a serious form of bone cancer known as osteosarcoma.
This evidence includes a government
animal study as well as several studies of human
populations living in the United States.
Osteosarcoma is a rare, but deadly, form of cancer that strikes primarily
during the teenage years. A national case control study published in 2006 by
Harvard scientists found that boys exposed to fluoridated water during their
6th, 7th, and 8th years of life (the mid-childhood growth spurt) had a
significantly elevated risk of developing osteosarcoma during adolescence. (Bassin
2006). The sex-specific link between fluoride and osteosarcoma in young males
is consistent with the government’s animal study, (NTP 1990), which found
osteosarcomas in the fluoride-treated male rats, but not the female ones. It is
also consistent with previous studies by the National Cancer Institute and New
Jersey Department of Health, which both found associations between fluoridation
and osteosarcoma in young males, but not females. (Cohn 1992; NCI 1990)
Although a number of studies have found no association
between fluoride and osteosarcoma, the Harvard study by Bassin is the only
study to ever carefully considered the “age-specific” risk of fluoride
exposure. As the renowned epidemiologist Kenneth Rothman explained to the Wall Street Journal:
“‘If there were an adverse effect of fluoride, it’s possible an effect of early exposure would be manifest in the first 20 years of life – but not after.’ Looking at all ages, in other words, could conceal any link between fluoridation and cancer.”
Fluoride/Osteosarcoma Link Is “Biologically Plausible”
It is widely acknowledged that the fluoride/osteosarcoma
connection is a biologically plausible one. When the connection
between a chemical and a cancer is biologically plausible, studies that detect
an association between the two are taken more seriously, as the association is
less likely to be a random fluke.
The plausibility of a fluoride/osteosarcoma connection is grounded in the three
considerations:
- Bone is the principal site of fluoride accumulation, particularly during the growth spurts of childhood;
- Fluoride is a mutagen when present at sufficient concentrations; and
- Fluoride stimulates the proliferation of bone-forming cells (osteoblasts), which may ”increase the risk for some of the dividing cells to become malignant.” (NRC 2006).
Fluoride & Bladder/Lung Cancer
In addition to osteosarcoma, a number of studies of fluoride-exposed workers have found associations between airborne fluoride exposure and both bladder and lung cancer. Although fluoride’s association with these cancers has generally been attributed to poly aromatic hydrocarbons (PAH) — a non-fluoride airborne contaminant — a twenty-year study of a workplace with no PAH exposure found a similarly elevated rate of both bladder and lung cancer in the fluoride-exposed workers. (Grandjean 2004). Based on these findings, the authors concluded that “fluoride should be considered a possible cause of bladder cancer and a contributory cause of primary lung cancer.”
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