As policymakers work to curb mercury pollution, they should consider the history of another dangerous metal.
According to some estimates, the use of leaded gasoline stole five or more IQ points from those of us who grew up in big U.S. cities during the 1960s and early 1970s, when contamination peaked. Studies show that children with higher levels of lead in their baby teeth do worse on tests of reading ability, grammatical reasoning, vocabulary, reaction times and hand-eye coordination.
And the doses back then were massive — typical kids had blood levels five times what’s known to cause brain damage. In case there was any doubt, newer studies confirm that lead’s damaging effects on children are permanent.
Eventually, science moved policymakers to take action. Now people around the world face the same challenge with mercury — another metal that’s toxic to children’s brains. Do we stall and debate while risking harm, or act with a greater level of precaution? The lessons of the past offer some guidance.
One reason 20th-century companies were able to spew so much lead into the environment was that the onus was on scientists to prove it was dangerous. Food and drug manufacturers, at least, had to demonstrate their products were safe before they hit the market, said Gerald Markowitz, a historian and co-author of the book “Lead Wars: The Politics of Science and the Fate of America’s Children.”
But for environmental pollutants and chemicals that people were exposed to in their jobs, industry generally didn’t act until a substance was proven hazardous. That was supposed to change in the 1970s with the Toxic Substances Control Act, he said, but in reality, it didn’t.
For the rest of this article: https://www.bloomberg.com/view/articles/2017-10-17/learning-from-the-fight-against-lead