US health officials have lowered the safe threshold for fluoride in drinking water to 0.7 milligrams per liter, because Americans now get fluoride from a variety of sources and no longer need as much in their tap water.
Portland voters soundly rejected fluoridation of the city’s water, reversing a 2012 mandate by the city council. Anti-fluoride forces are calling the vote a victory for modern science, which has identified excessive fluoride exposures as contributing to thyroid disease, bone damage and lower IQs among children.
Fluoride has been controversial for longer than many of us have been alive. Back in the 1940s and 50s, when scientists introduced the idea of adding fluoride to our water systems to strengthen Americans’ teeth, people fought the effort.