A century of hair samples proves leaded gas ban worked

"Science also produced a hero in this saga: Caltech geochemist Clair Patterson. Along with George Tilton, Patterson developed a lead-dating method and used it to calculate the age of the Earth (4.55 billion years), based on analysis of the Canton Diablo meteorite. And he soon became a leading advocate for banning leaded gasoline and the "leaded solder" used in canned foods. This put Patterson at odds with some powerful industry lobbies, for which he paid a professional price."

"But his many experimental findings on the extent of lead contamination and its toxic effects ultimately led to the rapid phase-out of lead in all standard automotive gasolines. Prior to the EPA's actions in the 1970s, most gasolines contained about 2 grams of lead per gallon, which quickly adds up to nearly 2 pounds of lead released via automotive exhaust into the environment, per person, every year."

"Lead can linger in the air for several days, contaminating one's lungs, accumulating in living tissue, and being absorbed by one's hair. Cerling had previously developed techniques to determine where animals lived and their diet by analyzing hair and teeth. Those methods proved ideal for analyzing hair samples from Utah residents who had previously participated in an earlier study that sampled their blood."

Clair Patterson developed a lead-dating method that established Earth's age and then campaigned against leaded gasoline and leaded solder in canned foods despite industry opposition. Experimental findings demonstrated widespread lead contamination and toxic effects, prompting rapid phase-out of leaded automotive gasoline after EPA actions in the 1970s. Before the phase-out, typical gasoline contained about 2 grams of lead per gallon, resulting in nearly two pounds of lead released per person per year via exhaust. Lead persists in air for days, deposits in tissue, and is absorbed in hair; hair-analysis techniques were applied to Utah residents from historic smelting towns to document exposure.

Read at Ars Technica