A century of hair samples proves leaded gas ban worked

The Environmental Protection Agency (EPA) cracked down on lead-based products—including lead paint and leaded gasoline—in the 1970s because of its toxic effects on human health. Scientists at the University of Utah have analyzed human hair samples spanning nearly 100 years and found a 100-fold decrease in lead concentrations, concluding that this regulatory action was highly effective in achieving its stated objectives. They described their findings in a new paper published in the Proceedings of the National Academy of Sciences.