Clair Patterson

Clair Cameron Patterson was an American geochemist hailing from Iowa. In the 1950s, Patterson and his colleague George Tilton produced a calculation of the age of the Earth, which equaled to 4.55 billion years, using radiometric dating at the University of Chicago, over a billion years older than previous estimates. Patterson's estimate has held as the scientific consensus since he published his findings.

Following this breakthrough, Patterson continued dating rocks, which led to a second important discovery: the amount of lead in the environment was much higher than the lead content in sediments, which meant humans were pumping way too much of the stuff into the atmosphere. The main source of this excess lead was quickly traced to the in leaded gasoline. Patterson spent the remainder of his career as an activist to reduce environmental lead, seeing success in the 1970s, when catalytic converters were made mandatory for all new cars. Leaded gasoline would later be banned in every country, as Patterson's and others' studies came to the attention of every government. Following this, he conducted studies concerning lead content in food.

Patterson spent much of his career working in poorly-funded labs, and was excluded from higher-paying jobs, scientific panels, and larger studies thanks to the influence of The Sadly, he remains rather obscure today, despite his important contributions to science.