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April 16, 2014

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Nevada mines release most mercury

Nevada's mines account for most of the mercury released into the environment in the United States, but the state is no longer No. 1 when it comes to release of toxic substances, according to an annual report released last week by the federal Environmental Protection Agency.

Alaska moved into the No. 1 spot, bumping the Silver State to second, after four straight years in which Nevada was first. Metal mining, which churns up to the surface the intrinsic toxic substances in soil and rock, perpetually puts Western states atop the list.

The report was based on data from 2002, when Nevada industries reported releasing 499 million pounds of toxic chemicals into the land, air and water -- 10.4 percent of the nation's total, 4.8 billion.

And Nevada's gold and silver mines remain nearly the sole source for the nation's mercury releases, the report said: 88.7 percent of the mercury released into the environment in 2002 was in Nevada. No other state had even 2 percent.

Experts said Nevada's shift in the overall rankings was caused not by changes in mining practices or volume but by a court-ordered alteration of how much toxic material mines have to report.

Referring to the reporting change, Carol Raulston, spokeswoman for the National Mining Association, said, "As a result, our (mining's) numbers went down significantly in the 2002 report."

The mining industry nationwide reported 2.8 billion pounds of toxic releases in 2001 and 1.3 billion pounds in 2002.

The mining industry says the new reporting method reflects more accurately the real dangers of the toxic chemicals, but environmentalists complain that vast amounts of pollutants are no longer being disclosed.

Digging up metals generates enormous piles of rock, which may contain trace amounts of potentially harmful substances. A federal court ruled last year that many of those substances need not be reported if they are less than 1 percent of the weight of the pile.

But those trace amounts add up to 1.5 billion pounds -- the difference between last year's and this year's total -- said Lauren Pagel, legislative assistant for the Washington-based nonprofit Earthworks.

"Because the waste rock that these toxic chemicals are in is such a huge amount, the concentration of toxics is small but the actual number ends up being huge," Pagel said.

To the industry those small concentrations exaggerate mining's impact on pollution. "If we were talking about air or water releases, that's probably a legitimate point to raise," Raulston said.

"These are not toxics we generate as part of our production process," she said. "It's not stuff we're generating and then emitting. It's just stuff Mother Nature put in the soil, and we move it."

Some especially dangerous substances, such as mercury and lead, must still be reported no matter how low the concentration. That appeared to be the reason Alaska became No. 1 on the list: the world's largest lead mine is in Alaska.

Even though the toxic substances occur naturally in the soil, disrupting the earth's surface and exposing them could have unforeseen effects, environmentalists claim.

"Our main concern is, this is a toxic substance being released into the environment. It's not going to go away," said Cristi Barker, a Las Vegas representative for Great Basin Mine Watch.

"Potentially, it can get into the soil or into drinking water or into lakes, rivers and streams," Barker said.

Mercury is of special concern because it is toxic in small amounts and can cause permanent brain and kidney damage. It accumulates in animals, then accumulates in the predators that eat them, thereby moving up the food chain.

A small but worrisome portion of mines' mercury emissions is not on land but airborne, Barker noted. To extract the gold, mines heat up or "roast" rock, thereby turning the mercury into a gas.

"The state of Idaho is starting to notice increased mercury levels in streams, rivers and lakes, and they're beginning to track this increase back to roasters in northern Nevada," Barker said.

Nevada mines released more than 9,000 pounds of mercury into the air in 2002, the report said. Texas, Ohio and Pennsylvania released more airborne mercury, which is also a byproduct of coal-burning power plants.

A Nevada gold mine, Jerritt Canyon, located 50 miles north of Elko, was the nation's single largest emitter of airborne mercury.

"Everyone's trying to reduce mercury emissions," Raulston said. "Some years ago, the gold industry voluntarily undertook a program to reduce mercury air emissions."

Nevada produces 81 percent of the nation's gold, worth 2.4 billion in 2002. If the state were a country, it would be the third largest gold-producing nation.

Nevada's mining industry employed 10,470 people in 2002 at an average salary of $63,236, according to the mining association.

The EPA's Toxics Release Inventory is intended to provide information on environmental pollution to the public. Industries are not subject to regulation or disciplinary action based on what they report.

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