62 l © 2025 American Dental Association
Section 2: Safety
American Cancer Society
In addition, the American Cancer Society’s (ACS) website provides basic information regarding water
fluoridation, as well as information on a number of studies that examined the possible association
between fluoridation and cancer. Many of these are referenced by the ACS, which states:
“The general consensus among the reviews done to date is that there is no strong evidence
of a link between water fluoridation and cancer. However, several of the reviews noted that
further studies are needed to clarify the possible link.”293
ACS also notes more recent research on this potential link, reporting that these studies have not found
an increased risk of osteosarcoma in areas of water fluoridation.194,293
33. Does fluoridated water cause osteosarcoma?
Answer
No. The best available scientific evidence shows that fluoridated water does not cause
osteosarcoma.
Fact
The National Cancer Institute estimates that a total of 1,000 people, including 440 children and teens,
would be diagnosed with osteosarcoma (a form of bone cancer) in the United States each year.294 About
2% of all childhood cancers are osteosarcoma, which most often affects those between the ages of
10 and 30. Osteosarcoma is about 50% more common in boys than girls. The 5-year survival rate for
children and teens with osteosarcoma that is only in one place at the time of diagnosis is 70%.294
In 2014, researchers from England published the largest study ever conducted examining the possible
association between fluoride in drinking water and the risk of osteosarcoma or Ewing sarcoma.295
Analyzing 2,566 osteosarcoma cases and 1,650 Ewing’s sarcoma cases from 1980 to 2005, the study
found that higher levels of natural or adjusted fluoride in drinking water in Great Britain (England,
Scotland, and Wales) had no impact on the incidence of either osteosarcoma or Ewing’s sarcoma in people
aged 0–49. Water fluoride levels ranged from near zero to a maximum of approximately 1.26 ppm.295
In the United States, the most extensive study to date on the issue was led by Harvard researchers.
They collected information about newly diagnosed malignant bone tumors from nine US hospitals over
an 8-year period between 1993 and 2000. Funding and expert input for this case control study came
from three agencies of the NIH: the National Cancer Institute, the National Institute of Environmental
Health Sciences, and the National Institute of Dental and Craniofacial Research. To date, three analyses
have been published.
An exploratory analysis was published in 2006193 in which fluoride exposure was determined by CDC data
on fluoride levels in the community water supplies and residence study participants’ communities. The
analysis considered only cases under 20 years of age. At the time this study was conducted, it was assumed
that water consumption varied by climate and the optimal fluoride levels for community water fluoridation
were 0.7–1.2 ppm. The authors adjusted the fluoride exposure estimates based on the climate where
participants lived. A subsequent study found that water ingestion did not vary by climate in the United
States and supported a change in the recommended optimal fluoride levels from a temperature-
related range of 0.7–1.2 ppm to a single concentration, later to be determined to be 0.7 ppm.296
The exploratory analysis193 found that for boys at age 7, there was an increased risk for osteosarcoma.
However, no statistically significant increased risks were found at other ages for boys or girls. Logically,
Section 2: Safety
American Cancer Society
In addition, the American Cancer Society’s (ACS) website provides basic information regarding water
fluoridation, as well as information on a number of studies that examined the possible association
between fluoridation and cancer. Many of these are referenced by the ACS, which states:
“The general consensus among the reviews done to date is that there is no strong evidence
of a link between water fluoridation and cancer. However, several of the reviews noted that
further studies are needed to clarify the possible link.”293
ACS also notes more recent research on this potential link, reporting that these studies have not found
an increased risk of osteosarcoma in areas of water fluoridation.194,293
33. Does fluoridated water cause osteosarcoma?
Answer
No. The best available scientific evidence shows that fluoridated water does not cause
osteosarcoma.
Fact
The National Cancer Institute estimates that a total of 1,000 people, including 440 children and teens,
would be diagnosed with osteosarcoma (a form of bone cancer) in the United States each year.294 About
2% of all childhood cancers are osteosarcoma, which most often affects those between the ages of
10 and 30. Osteosarcoma is about 50% more common in boys than girls. The 5-year survival rate for
children and teens with osteosarcoma that is only in one place at the time of diagnosis is 70%.294
In 2014, researchers from England published the largest study ever conducted examining the possible
association between fluoride in drinking water and the risk of osteosarcoma or Ewing sarcoma.295
Analyzing 2,566 osteosarcoma cases and 1,650 Ewing’s sarcoma cases from 1980 to 2005, the study
found that higher levels of natural or adjusted fluoride in drinking water in Great Britain (England,
Scotland, and Wales) had no impact on the incidence of either osteosarcoma or Ewing’s sarcoma in people
aged 0–49. Water fluoride levels ranged from near zero to a maximum of approximately 1.26 ppm.295
In the United States, the most extensive study to date on the issue was led by Harvard researchers.
They collected information about newly diagnosed malignant bone tumors from nine US hospitals over
an 8-year period between 1993 and 2000. Funding and expert input for this case control study came
from three agencies of the NIH: the National Cancer Institute, the National Institute of Environmental
Health Sciences, and the National Institute of Dental and Craniofacial Research. To date, three analyses
have been published.
An exploratory analysis was published in 2006193 in which fluoride exposure was determined by CDC data
on fluoride levels in the community water supplies and residence study participants’ communities. The
analysis considered only cases under 20 years of age. At the time this study was conducted, it was assumed
that water consumption varied by climate and the optimal fluoride levels for community water fluoridation
were 0.7–1.2 ppm. The authors adjusted the fluoride exposure estimates based on the climate where
participants lived. A subsequent study found that water ingestion did not vary by climate in the United
States and supported a change in the recommended optimal fluoride levels from a temperature-
related range of 0.7–1.2 ppm to a single concentration, later to be determined to be 0.7 ppm.296
The exploratory analysis193 found that for boys at age 7, there was an increased risk for osteosarcoma.
However, no statistically significant increased risks were found at other ages for boys or girls. Logically,
