In an effort to examine the dramatic reduction in toxic heavy metal exposure, researchers turned to human hair samples dating back a century. That makes it easier because lead is not lost over time.”Fernandez and his team previously studied blood samples and family health histories of Utahns. This time, the team recruited volunteers from the Wasatch Front region in northern Utah to provide hair samples. “The Utah part of this is so interesting because of the way people keep track of their family history. It’s in the air for a number of days, especially during the inversions that we have and it absorbs into your hair, you breathe it and it goes into your lungs.”While gas consumption continued to rise in the ensuing decades, lead samples in hair dropped sharply.