Can fluoride chemicals be used to treat drinking water to improve dental health cause problems with lead (Pb) leaching from plumbing systems?

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This is a question that has been asked repeatedly throughout the years as the evidence about lead in drinking water has grown. The answer is a safe "maybe."

About two-thirds of the public water systems in the U.S. are fluoridated to help eliminate tooth decay, which remains a national epidemic according to the U.S. Surgeon General. Over 90% of fluoridated systems use fluorosilicic acid as their chemical of choice to add fluoride to drinking water.

There is research now indicating that the use of fluorosilicic acid in combination with chloramines for secondary disinfection enhances lead (Pb) leaching from plumbing systems. This increased lead at the tap could be coming from increased pipe corrosion, accelerated breakdown of old lead-containing pipe scale, or from some other unknown mechanism.

But by and large, the research shows that fluoride is the main culprit.

Fluoride chemicals, combined with other water additives, pull health-damaging lead from plumbing systems into drinking water, according to the University of North Carolina researchers reported a North Carolina newspaper on May 18, 2005. Fluoride is added to water supplies to prevent cavities, not purify it as some belief. A combination of chloramines and fluorosilicic acid, especially with extra amounts of ammonia, leaches lead from meters, solder, and plumbing systems, according to Richard P. Maas, PhD and Steven C. Patch PhD, co-director of the Environmental Quality Institute at the University of North Carolina, Asheville.

Chloramine, a combination of chlorine and ammonia, is a water supply disinfectant. Fluorosilicic acid, the chemical used by over 91% of U.S. fluoridating communities, attempts to improve dental health in those who drink it About 2/3 of U.S. public water supplies are fluoridated but tooth decay remains a national epidemic, according to the U.S. Surgeon General. Maas said, "Tests showed lead levels three and four times higher in water with that combination of chemicals. About 500 systems, across the country, have switched to chloramine treatment since 2001, and most also use fluorosilicic acid," according to the North Carolina newspaper, the News & Observer. Maas said this chemical interaction could be responsible for the elevated lead levels recently plaguing Greenville, North Carolina. Health authorities issued a lead advisory for water from the Greenville Utilities Commission when elevated lead levels showed up in 26 of 106 sampled homes. Water leaving the plant and its distribution lines do not contain lead.

But testing showed two children with harmful lead levels, leading health officials to speculate that corrosion of pipes within the home may be the cause. Greenville authorities warned pregnantly and breastfeeding women and children under age six to avoid tap water until it is tested for lead. Maas, who heads a lead poisoning prevention program in Western North Carolina funded by the federal Centers for Disease Control and Prevention, said his lab has tested more than 150,000 homes across the country in the past 18 years and found that 10 to 15 percent have a significant lead contamination problem, according to the News & Observer article. "No amount of lead is safe for a young child's developing brain," says Paul Connett, Ph.D., Professor of environmental chemistry and toxicology at St. Lawrence University in Canton, NY and Executive Director of the Fluoride Action Network.

"If this new data is confirmed, it will further underscore the negligence of U.S. authorities using fluorosilicic acid as a fluoridating agent in the absence of any research establishing the safety of this particular fluoride chemical," says Connett. These new findings may help explain earlier published, peer-reviewed research by Roger Masters, PhD of Dartmouth College, and Michael Coplan. Their studies show a link between water fluoridation status and elevated blood lead in children. Elevated blood lead levels are linked to developmental delays in children under age six and fetuses. Lead can adversely affect almost every organ and system in the body. The most sensitive is the central nervous system, particularly in children. Lead also damages kidneys and the reproductive system. The effects are the same whether it is breathed or swallowed. According to the Centers for Disease Control and Prevention, "fluoride works primarily after teeth have erupted." "It really doesn't make any sense to ingest fluoride chemicals, anyway. Fluoridation is an outdated concept, wastes money, jeopardizes the health, and should be stopped everywhere," says Connett.

One thing is certain, as far as the EPA is concerned, if further data confirm the link between chloramine disinfection and use of fluorosilicic acid, changes will be coming in drinking water treatment, most likely restrictions in the use of this particular chemical for fluoridation.

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