After U.S. Sen. Marco Rubio sidestepped a question on the age of
the earth, geochemistry has enjoyed a spurt of recent media
coverage. But did you know the chemist who established Earth’s
age — and prevented millions of lead poisoning cases in the
process — was a Grinnellian? In 1955, Clair C. Patterson ’43
studied lead ratios in meteorites to pinpoint Earth’s age at 4.5
billion years, a figure that has held for nearly six decades and
disproved the previous 3-billion-year estimate. Patterson, who
died in 1995, quickly recognized that if ancient meteorites
contained traces of lead, then the Industrial Age was drowning
in it. By studying pre-Iron Age mummies, he determined that lead
levels in modern humans were hundreds of times higher than in
their millennia-old ancestors. His findings led to congressional
hearings that paved the way to remove lead from products
including paint, pesticides, and gasoline. After growing up with
chemistry kits and a home lab in his parents’ Mitchellville,
Iowa basement, Patterson