Mercury pollution: Many questions some answers

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Here’s a look at mercury pollution in Colorado, from Mark Jaffe writing for the Denver Post. From the article:

The heavy metal, however, isn’t found in fish in all lakes or all species in tainted lakes — a phenomenon in Colorado and in other parts of the country. So scientists are now trying to unravel the mystery of why it pops up in Carter Lake walleye, but not those in Chatfield Reservoir. “We’ve got some very hot fish in some, but not in all our reservoirs,” said Nicole Vieira, a state Division of Wildlife aquatic toxicologist. “If we can figure out what is at work, we might be able to manage the fish stocks to reduce mercury,” she said. At the same time, Colorado has issued regulations requiring mercury air emissions from power plants — a prime source of the pollutant — be cut 90 percent by 2018…

A dusting of mercury is falling into lakes and rivers all across the country — the Environmental Protection Agency estimates more than 112 tons of mercury emissions was generated in 2005. Among the largest sources are power plants, cement kilns, refineries and commercial boilers, according to the EPA. But the inorganic mercury coming out of those smokestacks would just sit on a lake bottom if not for bacteria that turn it into methylmercury — which animals along the food chain can absorb. Every state has issued mercury health advisories on eating fish, according to the EPA. Methylmercury poisoning can impair vision, walking, speech and hearing. Children suffer neurological damage with just a tenth of the exposure it takes to harm adults. A pregnant woman eating tainted fish can also can hurt her baby’s growing brain and nervous system. Women of child-rearing age are also advised to limit consumption of mercury-tainted fish because it takes eight to nine months for the body to purge the toxic. Colorado advisories to limit consumption are triggered when 0.5 parts per million of mercury or more is found in fish tissue. “The more we learn, the more damaging mercury turns out to be to a child’s brain,” said Gina Solomon, a senior scientist with the Natural Resources Defense Council…

“It is a complicated process, and we are trying to break it down,” said Steven Gunderson, director of water quality for the Colorado Department of Public Health and Environment. Lake Pueblo, for example, is not far from a steel mill but has no fish advisories, Gunderson said. Brush Hollow Reservoir, 30 miles away in Penrose, has a mercury problem.

In 2004, the state health department and the Division of Wildlife drew up a list of the 120 most-fished bodies of water and began testing their fish. About 112 have now been tested, and 23 have fish with elevated mercury levels — from Totten Reservoir west of Durango to Horsetooth Reservoir near Fort Collins. The “hot” fish species have varied from lake to lake and include walleye, lake trout, northern pike, largemouth and smallmouth bass, yellow perch, saugeye and wiper. “These are all predators, top-of-the-food-chain fish, where the mercury gets concentrated,” said Alisa Mast, a hydrologist with the U.S. Geological Survey.

More Coyote Gulch coverage here.

One thought on “Mercury pollution: Many questions some answers

  1. How difficult and costly it is to remove mercury from water to make it drinkable for humans? Can some expert give the answer? IN some countries, people throws to rivers or lakes waste containing cells, amalgams scrap, broken termometers, etc.

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