A drop of mercury
I'm Bob Karson with the discovery files--new advances in science and engineering from the National Science Foundation.
(Sound effect: restaurant bg) Been a lot of talk lately about mercury levels in the food chain--you might think cutting down mercury emissions would solve the problem of this neurological and cardiovascular toxin. But a Harvard study now shows that in addition to new sources, we need to deal with mercury pollution from our ancestors.
(Sound effect: ancient music) Humans have been releasing mercury into the environment ever since the ancient Greeks and Chinese used it as a pigment. (Sound effect: early machinery) Then there's the whole industrial revolution, and the gold rush (Sound effect: mule) yep, our kind is responsible for most of the Hg found in the soil, air and water. The researchers, point out that nearly all of the mercury pollution from the last millennium is still around--a game-changer in terms of reducing the overall amount.
The study model showed that 60 percent of the mercury currently being deposited in the atmosphere is 'legacy' mercury released in the distant past but still cycling its way through the environment. Of the rest, 27 percent comes from our present-day emissions. Only 13 percent is natural in origin.
The Harvard team says that, with all this legacy mercury around, if we want to reduce the level of mercury in the environment, it's not enough just to stabilize the amount we're emitting now. We need to drastically reduce it.
Legacy mercury and they say diamonds are forever.
"The discovery files" covers projects funded by the government's National Science Foundation. Federally sponsored research--brought to you, by you! Learn more at nsf.gov or on our podcast.