Clair (Pat) Patterson; Fought Lead Contamination

Clair C. (Pat) Patterson, a Caltech geochemist who scientifically dated the age of the Earth and discovered lead contamination in modern humans, leading to the Clean Air Act of 1970, has died. He was 73.

Patterson, who had taught and done research at Caltech for four decades, died Tuesday at his home in Sea Ranch in Northern California.

Often referred to on campus as “the lead man� for his research determining that modern humans contain 1,000 times the lead of their prehistoric ancestors, Patterson argued that lead in combination with calcium cakes bones, clogs kidneys and diminishes children’s intelligence.

Based on his research begun in 1960, environmentalists have obtained curbs on lead-based paints, ended the sealing of canned goods with lead solder and passed the Clean Air Act to reduce emissions from cars burning leaded gasoline. The EPA showed that the act cut lead emissions 96% in its first 20 years.

Earlier this year, in recognition of his lead research, Patterson was awarded the top international environmental award, the Tyler Prize for Environmental Achievement.

Patterson considered his efforts to save humanity from lead a way of practicing socially responsible science, and penance for his early research in developing the atomic bomb during World War II.

“It was the greatest crime that science has committed yet,� he told The Times in 1990.

His first landmark research occurred in 1953 when he decisively pinpointed the age of the Earth at 4.6 billion years.