Higher mercury concentrations may be more widespread in Idaho than anyone thought.
The latest place where high mercury was found was in Lake Billy Shaw, Sheep Creek Reservoir and Mountain View Reservoir on the Duck Valley Indian Reservation on the Nevada border and Wildhorse Reservoir in northern Nevada. This fits into the current hypothesis of Idaho environmentalists that high mercury levels are tied to emissions from Nevada gold mines or from a concrete plant in Oregon with high emissions.
But state scientists are finishing up a report that may show widespread mercury contamination throughout the state’s waters. We’ll have to wait until early next year to see the results because all the analysis work still needs to be done.
All of this mercury in our environment is troubling because of the effects. Mercury has long been known to be a deadly poison in high doses. Methylmercury is the organic form that is the most toxic.
Children of women exposed to relatively high levels of methylmercury during pregnancy show delayed onset of walking and talking, reduced neurological test scores, and delays and deficits in learning ability, according to U.S. Environmental Protection Agency reports.
Eight percent of women of childbearing age nationally have levels of mercury in their blood that exceed the level EPA considers safe, mostly because of fish contamination, the EPA said. Growing evidence also shows that methylmercury exposure can have adverse cardiovascular effects for adults, resulting in elevated blood pressure and incidence of heart attack, EPA officials say.
Mercury is released into the atmosphere by many industrial processes, especially coal-fired power plants and mines. Most of the mercury pollution is elemental mercury, which is not as toxic. But it mixes in the atmosphere with other chemicals and is transformed through oxidation and other processes after it is deposited over the land into the more lethal methylmercury.
It then washes into waterways at widely varying rates. In rivers and lakes, it moves up the food chain to concentrate at high levels in the flesh of fish. Some mercury is carried around the world, and some drops out of the atmosphere in rain and snow or in dry form.
When forest fires burn decades of deposited mercury is released into the air.
Nevada’s mine aren’t the only ones that use the roasting process to extract ore. The technology is used worldwide.
China is building coal-fired-power plants at a break-neck pace adding more mercury to the environment. Scientists are only beginning to understand the deposition process.
The U.S. Geological Survey and the Shoshone-Paiute tribes found that about 70 percent of the rainbow trout filets sampled contained mercury concentrations greater than what could normally be expected according to a report by the Associated Press Reporter John Miller in Boise.. The average U.S. mercury concentration for rainbow trout is 0.11 parts per million.
The latest data adds to support for Gov. Butch Otter’s policy to learn more about mercury and to work with neighbors to reduce it at the source.
By the way, Wyoming reported its mercury health advisory, warning anglers to limit meals for women of child-bearing age and kids of fish from Big Horn, Seminoe and Pathfinder reservoirs. In northwest Wyoming.