Prophylactic vs. Poison

The will of the voters in Portland, Oregon has endured for more than fifty years, for the fourth time rejecting fluoridation of the city’s tap water in a ballot referendum.  On Respectful Insolence, Orac writes “public water supplies are a precious commodity. To justify putting something in them requires good evidence of safety and efficacy.”  And continues “since 1945 the fluoridation of drinking water has reduced tooth decay by 40-70% in children and tooth loss in adults by 40-60%.”  Orac respects Portlanders’ right to more cavities, but says “classic antiscience arguments” won the day at the polls.  There were posters and comics likening fluoride to a deadly poison—which, in drastically different concentrations, it is.  Orac says “the dose makes the poison, and the levels used in municipal water supplies has a long history of safety.”  Elizabeth Grossman chronicles a different poison on The Pump Handle: lead, which according to the CDC, will harm you from any exposure.  Unlike fluoride, lead plays no known role in human health, and can cause severe neurological damage.  But it does have useful properties when mixed with paint (among other things).  The US banned lead paint in 1977, but it still exists in some 30 million homes across the country, and is still used worldwide.