On December 5th, 1995, Clair C. "Pat" Patterson, who won the prestigious Tyler Prize for Environmental Achievement in 1995, passed away at his home in The Sea Ranch, California, northwest of Santa Rosa. He was 73.

Patterson, who had a remarkable talent for finding the most important scientific problems and then solving them, is best known for his determination of the age of the earth and the solar system, and for his pioneering work on lead pollution in the modern world. The passion that directed Patterson's research was his desire to better understand the geochemistry of metals in terrestrial rocks, waters, and atmospheres, in meteorites, and in the solar system. Patterson was a pioneer in the study of lead in the earth's crust. He developed precise analytical techniques that enabled him to establish the true levels of pre-industrial lead in the environment. His analysis of lead isotopes in meteorites and oceanic minerals led him in the early 1950s to conclude that the earth and solar system are 4.6 billion years old.

This result is one of the most important measurements of time ever made. Current theories of stellar birth and evolution, and our very understanding of the history of the universe, are based in some measure on this important measurement. While studying lead isotopes, Patterson found that human civilization had mined and dispersed an unprecedented amount of the metal around the world. Ice cores from the Greenland ice cap, dating back thousands of years, showed that the amount of lead in modern snow is much higher than in pre-industrial times.

This knowledge led Patterson to wonder whether this abundance of lead might affect humans. His studies of the bones and teeth of prehistoric people confirmed that modern humans contain up to 1000 times more lead than their ancient ancestors.

His message, that people were being contaminated by lead from water pipes, from leaded gasoline, and from the solder used to seal canned foods, was not a popular idea. But Patterson was a courageous and determined man, and he knew that he was right. He fought, against great odds and the money of powerful corporations, to discontinue the use of lead in these materials, and eventually, through his tenacity and his extremely thorough methods, his results and recommendations were accepted.

Patterson was born in Des Moines, Iowa, and earned his bachelor's degree in chemistry at Grinnell College in Grinnell, Iowa, in 1943. He continued to study chemistry at the University of Iowa, where he earned his master's degree in 1944, and at the University of Chicago, where he completed his doctorate in 1951 with Harrison Brown as his thesis advisor. He stayed on at the University of Chicago as a postdoctoral fellow for one year, and when Brown came to Caltech to establish the geochemistry program in 1952, Patterson came with him as a research fellow. At the time of his death, Patterson was professor of geochemistry, emeritus. Among his many honors, Patterson received the J. Lawrence Smith Medal from the National Academy of Sciences in 1975 and the Professional Achievement Award of the University of Chicago in 1981. He was elected to the National Academy of Sciences in 1987 and has also had a peak in Antarctica and an asteroid named for him. In 1995, he won The Tyler Prize for Environmental Achievement, the premier international environmental honor in the world.

Additional Links

Getting the Lead Out

Caltech's Apollo Connection