Sunday, 21 May 2017

plumbum or better living through geochemistry

Mental Floss has a thorough and circumspect long-format profile on scientist Clair Cameron Patterson that’s a fascinating bit of triangulation among the applied sciences, scholastics and environmental policy that is a fascinating biographic study in its own right and especially timely in this contemporary political environment when science is under assault—as are policies and regulations that promote public health and safety. To summarise (but it’s worth one’s while to read the article in its entirety) Patterson joined the Manhattan Project early on at the facilities at Oak Ridge Tennessee and figured out how to use mass spectrometers to separate out uranium isotopes and create enriched batches of the critical mass to sustain a nuclear explosion. After the war, Patterson took a teaching job and like so many scientists were eager for the chance for purely academic pursuits after having in the spirit of project leader J Robert Oppenheimer’s quote from the Bhagavad Gita “now I am become Death, the destroyer of worlds” and was given an errant mission from a colleague to accurately measure the age of the Earth for the first time.
Having advanced from three thousand years old, to over ten thousand, several hundred thousand to millions and even billions, the scientific community had a ball-park figure and the consensus was generally not beyond three billion years old at this time. From his days as a nuclear researcher, Patterson knew that uranium had a given half-life at which point it would break-down into lead, and postulated that by sampling the ratio of lead to uranium inside very old rocks, he might be able to derive a more accurate means of dating the planet. His mass-spectrometry technique might be able to tease out these numbers but wherever he looked—even under laboratory conditions—there just seemed to be far too much lead, and instead of concluding that the world was many magnitudes older than experiments suggested, Patterson investigated further. Parallel to Patterson’s life and career, the automotive and petroleum industry had been advancing a-pace and sort of like that proverbial old woman that swallowed a fly, to alleviate the need for cranking a car to start it, then to reduce the infernal smells of fuel additives, then to eliminate noxious noise from engine knocking, chemist finally settled on what seemed to be the ideal solution of adding lead to petroleum. This meant that especially in urbanised areas, lead pollution and poisoning (the body’s biology misapprehends lead for calcium with highly toxic consequences) were impossible to get away from. Going to great efforts after conducting environmental sampling from remote and pristine areas to disabuse the public from the idea (propagated by the automotive and oil industries) that these levels of lead in the air and in the blood-stream and household products (paint, food cans, shoe heels, plumbing—the Romans knew better, etc) was acceptable or within healthy tolerances, Patterson created the world’s first ultra-clean room, free from outside pollutants, not only calculating the age of the Earth to four billion five-hundred million years but also directly launching a campaign against lead contamination that went on for decades and has been championed by many others. Patterson’s research, though it was a tough battle against the industry who had government in their back pockets, eventually saw the gradual removal of lead from products and a marked improvement in public health as a result. Stories like these seem to make our backsliding all the worse.