Tracing The Geochemical Evolution of The Earth
His ability to isolate microgram quantities of lead from ordinary rocks and determine their isotope composition led him to examining the lead in ocean sediment samples from the Atlantic and Pacific. Deriving from the different ages at which the landmasses had drained into the ocean, he was able to show that the amount of anthropogenic lead presently dispersed into the environment was about eighty times the amount being deposited in the ocean sediments: the geochemical cycle for lead appeared to be badly out of balance.
The limitations of the analytic procedures led to him using other approaches. He found that deep ocean water contained 3-10 times less lead than surface water, in contrast to similar metals such as barium. This led him to doubt the commonly held view that lead concentrations had only grown by a factor of two over naturally occurring levels.
Patterson returned to the problem of his initial experiment and the contamination he had found in the blanks used for sampling. He determined through ice-core samples from Greenland that atmospheric lead levels had begun to increase steadily and dangerously soon after tetra-ethyl lead began to see widespread use in fuel, when it was discovered to reduce engine "knock" in internal combustion engines. Patterson subsequently identified this, along with the various other uses of lead in manufacturing, as the cause of the contamination of his samples, and because of the significant public-health implications of his findings, he devoted the rest of his life to removing as much introduced lead from the environment as possible.
Read more about this topic: Clair Cameron Patterson
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