Clair Patterson

Determined Earth’s age and exposed global lead pollution, catalyzing environmental reforms

Clair Cameron Patterson (1922–1995) was a geochemist whose groundbreaking work reshaped both planetary science and public health. Using uranium-lead dating on meteorites, he calculated Earth’s age as 4.55 billion years—a figure still accepted today. This achievement, detailed in his 1953 paper, resolved decades of debate and earned him recognition from institutions like the California Institute of Technology.

Patterson’s subsequent research revealed alarming lead concentrations in the environment and human bodies. He traced the source to tetraethyl lead in gasoline, contradicting industry claims of safety. His relentless advocacy, supported by organizations like the EPA, led to the 1970s ban on leaded gasoline in the U.S., drastically reducing blood lead levels worldwide.

Despite facing opposition from corporations, Patterson’s work exemplifies science’s role in societal change. Documentaries like Invisible Poison highlight his crusade, while modern studies on lead’s neurotoxic effects validate his findings. The Nobel Prize-winning IPCC reports also draw inspiration from his interdisciplinary approach. Patterson’s dual legacy in geochemistry and environmental activism underscores the power of rigorous science to ‘make a difference.’