Anyone with an interest in lead pollution and contamination owes it to themself to read about Clair Patterson, one of the most important scientists you’ve probably never heard of. He started his career as a chemist working on the Manhattan Project, and had the normal postwar crisis of conscience that so many of the scientists on that project had. He decided to work only on projects that could have no possible military value. When studying for his PhD he was part of the team that was the first to accurately estimate the age of Earth.

His part of that project involved comparing isotopes of lead in zircon crystals in meteorites. He had endless problems with his experiments because he couldn’t nail down the source of outside lead contamination. He eventually built the first proper ulta-clean-room laboratory and successfully completed his experiments, but being a good chemist he knew the dangers of lead to human health, and made it his life’s work to find out where it was coming from and try to stop it. The more places he looked, the more lead he found, and the more concerned he became for public health. He literally travelled the world, collecting samples of everything from polar ice cores to Peruvian mummies to try to determine what the natural pre-industrial lead levels were compared to contemporary lead levels. His body of work was critical in phasing out lead in so many industrial and commercial products.