A Natick chemist whose research has linked fluoridated water to elevated levels of lead in children’s blood is trying to convince state lawmakers to defeat a proposal that would mandate fluoridation of most public water supplies.

About 30 lawmakers are trying to require adding fluoride to water supplies that serve at least 5,000 people. Dental groups and many public health agencies, including the U.S. Centers for Disease Control and Prevention, promote fluoridating tap water because they say it prevents tooth decay.

But some researchers have concluded that fluoridated water is harmful to children’s health, including Natick chemist Myron Coplan and Roger Masters, president of the Foundation for Neuroscience and Society at Dartmouth College and the college’s Nelson A. Rockefeller Professor of Government Emeritus.

Coplan and Masters linked fluoridated water to elevated lead levels in the blood of children ages 0 to 6 in research published in the December 2000 issue of the journal Neurotoxicology.

Coplan, 83, retired in 1987 and has been collaborating with Masters for eight years in an ongoing study of environmental toxins and their effect on children’s health and behavior.

This week, the two researchers warned that elevated blood lead levels in children cause cognitive impairment and suppressed impulse control in written testimony submitted to the Legislature’s Joint Committee on Public Health, which has scheduled a public hearing on the fluoride proposal for today. “Evidence published in peer-reviewed journals indicates that chronic ingestion of (fluoride)-treated water is a cause of elevated blood lead in children,” Coplan and Masters wrote in their testimony. “Independent, new research has provided an explanation for the elevated blood lead. Unexpected amounts of lead are extracted from brass plumbing fixtures by water in which (a type of fluoride known as fluosilicic acid) is combined with chlorine or chloramine disinfectants.”

Fluoride, which also has been linked to bone structure defects and bone cancer, is added to water supplies in 135 Massachusetts cities and towns, more than one-third of the state. Some believe the decision should be left up to each community.

“I think it should be up to the individual cities and towns, because there’s pros and cons,” said Paul Mazzuchelli, the health director in Milford, which does not fluoridate water. “I think (cancer concerns) have some legitimacy to it. When anything comes out like a health risk, it should be studied.”

Supporters of fluoride use say the chemical has been studied enough.

“There has never been any credible evidence or data to suggest that fluoridation has been linked to any type of disease,” said Robert Alconada, director of governmental affairs for the Massachusetts Dental Society. “We’re talking about…60 years of scientific research on the effectiveness and safety of fluoride.”
But one recent study that declared fluoride safe, by Harvard University dentistry professor Chester Douglass, has come under scrutiny.

The Environmental Working Group filed an ethics complaint because Douglass claimed research conducted by a doctoral student supported his contention that fluoridated water poses no significant risk, even though the student’s thesis found a strong link between fluoridated tap water and osteosarcoma — a type of bone cancer — in boys.

Also, a study completed in 1991 by the U.S. Public Health Service found significantly elevated rates of bone cancer among males under 20 in fluoridated communities.

Public Health Committee co-Chairman Rep. Peter Koutoujian, D-Waltham, would not predict how the Legislature will act on the fluoride proposal. He says he will keep an open mind.

“I’m wide open to this,” Koutoujian said. “I know there’s some dispute about the studies out there. I’m willing to listen.”

Today’s public hearing is scheduled for 10:30 a.m. in room A-2 of the State House. The fluoride bill will likely be taken up at 1:30 p.m., Koutoujian said.