Science Diary: How Toxins Move – Clark Fork River
Music; Ambience: Sounds from near the Clark Fork
MH: “Coming down this river today we have traces of what’s left over from that mining, in terms of contaminant heavy metals.”
JM: Welcome to Pulse of the Planet’s Science Diaries, a glimpse of the world of science from the inside. Michael Hochella is a geochemist at Virginia Tech. He’s out been west trying to find out why contamination from mines has been able to travel much further and faster down river than has been predicted.
MH: “I’m gazing down at the Clark Fork River as it winds its way through ponderosa pine forest in Western Montana. And later on this summer I’m going to be collecting water samples all the way to the headwaters, which is about a hundred and twenty miles from here. And about a century-and-a-half ago mining started in that area, mining first for silver and later for copper and zinc. And in the 1800s this became one of the largest mining areas in the world. The problem with that was that it created a huge amount of metal contamination, which are toxic to life as you come down the river.”
JM: This region is known as the Clark Fork River Superfund site. Superfund sites are areas that the Environmental Protection Agency has declared potentially hazardous and in need of containment and cleanup. The Clark Fork River site covers nearly 2,000 square kilometers of contaminated land, making it the largest Superfund site in the United States.
MH: “We’re trying to figure out how toxic heavy metals, metals that can interact with living things, including people, and harm them, how they have gotten so far away from where they originated at the mining sites?
JM: Pulse of the Planet’s Science Diaries are made possible by the National Science Foundation. I’m Jim Metzner.