Way to go Thailand. Next you'll be inventing the wheel.
Quote:
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 Camp Century in Greenland taken in 1964 and from Antarctica in 1965, that atmospheric lead levels had begun to increase steadily and dangerously soon after tetraethyl lead began to see widespread use in fuel, when it was discovered to reduce engine knock in internal combustion engines. Patterson subsequently identified that, along with the various other uses of lead in manufacturing, as the cause of the contamination of his samples. 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.[8]
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Above from: https://en.wikipedia.org/wiki/Clair_Cameron_Patterson