Ice-core schematic · lead thickens toward the present. No public-domain photograph of him could be confirmed.
Clair Patterson
1922 — 1995
He set out to date the Earth — and found the whole planet, and everyone on it, laced with lead.
In 1953, a young chemist from Iowa flew to Chicago carrying a few specks of lead he had coaxed out of the Canyon Diablo meteorite, the iron that blasted Meteor Crater into the Arizona desert. He fed them to a mass spectrometer, and out came an answer no one had managed before: the Earth is about four and a half billion years old. Refined to 4.55 billion in 1956, his figure is still the one in textbooks.
His adviser had promised it would be “duck soup.” It took years, because every sample kept showing far too much lead — from the reagents, the glassware, the air, his own hair. Clair Patterson traced it to the tetraethyl lead in gasoline, and then spent three decades telling the world it was being poisoned. He lost funding and was left off a national lead panel. In the end he won.
From the farmland to the clean room
The lifeline
1922
Born June 2 in Mitchellville, Iowa, son of a rural mail carrier
1944
Joins the Manhattan Project, Chicago then Oak Ridge; learns the mass spectrometer
1953
Meteorite lead gives the first measured age of the Earth: ~4.5 billion years
1965
Publishes the alarm: industrial lead has swamped the natural kind in all of us
1980
Files a 78-page minority report against a too-timid national lead panel
1995
Dies December 5 at Sea Ranch, California, aged 73, just before the U.S. bans leaded gasoline for road vehicles
By the numbers
The measure of him
4.55 bn
Years: the age of the Earth he published in 1956, ± 70 million. It still stands.
700–1,200×
More lead in modern bones than in 1,600-year-old Peruvian skeletons (1979)
78
Pages in his dissent from the National Research Council’s 1980 lead report
77%
Fall in average U.S. blood lead, 1976–80 to 1988–91, as leaded gas was phased out
What he measured, and what it meant
The work
1948–51
Ages from zircons. With George Tilton at Chicago, he measured lead in pinhead crystals at amounts, as he put it, “a thousand times smaller than anything anyone had ever looked at before.”
1953
The age of the Earth. Lead from the Canyon Diablo meteorite, cleaned in one of the first ultra-clean labs at Caltech and measured in Chicago, gave the first published figure.
1956
4.55 ± 0.07 billion years. Adding stony meteorites to the iron, he fixed the number in Age of Meteorites and the Earth.
1965
The lead alarm.Contaminated and Natural Lead Environments of Man argued that “normal” human lead levels were nowhere near natural.
1966
Before the Senate. At Senator Muskie’s air-pollution hearing on June 15, he warned officials against confusing “normal” with “natural.”
1969
The polar record. Snow sawn from Greenland and Antarctic shafts showed modern Greenland snow holding over 100 times the lead of pre-industrial layers.
1979
Ancient bones. Skeletons buried in Peru 1,600 years ago held 700 to 1,200 times less lead than modern ones, with no such change in barium or calcium.
Shut out, then proven right
Recognition
While he fought
Federal funders turned down his proposal to date the Earth; his adviser had to resubmit it under his own name
When the lead work threatened gasoline, the oil-company money behind his lab dried up
Left off the National Research Council’s 1971 panel on airborne lead
Colleagues told him to stop “worrying about … this health crap” and get back to science
After
Goldschmidt Medal (1980), National Academy of Sciences (1987), Tyler Prize (1995)
Leaded gasoline banned for U.S. road vehicles from January 1, 1996
Asteroid 2511 Patterson and a peak in Antarctica’s Queen Maud Mountains carry his name
The Geochemical Society’s C. C. Patterson Award, given every year since 1998
The place that made him
Caltech, Pasadena
He arrived in 1952 as a research fellow and stayed for good, building one of the first ultra-clean labs. He redistilled his own reagents, and his crews sawed polar snow in acid-cleaned suits and gloves. Scientists came from around the world to learn how to measure lead there. “The Institute has a whole lot of things wrong with it,” he said in 1995, “but because this Institute existed, I existed.”
1952
Arrives as a research fellow, one of the founders of Caltech’s geochemistry program
1,000×
How much less lead was in polar snow than in other labs’ “pure” water
1989
The year he finally accepted a professorship, three years before retiring
“This proves that for 2,000 years we have been unable to understand the evil that we are doing to ourselves and the biosphere.”
— Clair Patterson, 1995, on polar ice that tracked ancient lead smelting