GRAND RAPIDS, Mich.-The great American assault on tooth decay began here 63 years ago, earning Grand Rapids a special place in the annals of dental history: the first city in the world to fluoridate its public water system.<\/p>\n
So it is more than a little head-scratching that fluoride, the chemical widely credited with dramatically cutting cavities and promoting oral hygiene, is having its scientific credentials questioned in the city that literally swallowed it first.<\/p>\n
The belated questioning of fluoride in the most unlikely of places stems partly from unsettled questions-some new, some old-about possible links to cancer and thyroid and kidney problems if too much fluoride is ingested. But the push here mirrors a spreading nationwide awareness and re-examination of the health impact of a wide variety of chemicals added to food, health-care products and water, as well as the use of pesticides. A Tribune examination of Chicago’s drinking water this year found traces of pharmaceuticals and personal-care products.<\/p>\n In California, several communities are cracking down on aerial pesticide spraying because of its potential impact on humans and animals. Experts predict that in-depth examinations of chemicals formerly considered benign will become more frequent.<\/p>\n “I think this pattern has been growing because there is better environmental health research that draws connections between low levels of chemical exposure and changes in our bodies,” said Dr. Howard Hu, chairman of environmental health sciences at the University of Michigan. <\/p>\n
Unusual findings
<\/strong>Local and state governments around the nation are taking a second – and in some cases a first – look at chemical practices and their potential impact. A county in Utah has stopped encouraging people to flush unused prescription drugs down the toilet because they might contaminate the water system. That action was taken after a report from the U.S. Geological Survey found chemicals from prescription drugs in streams and rivers.<\/p>\n