Editorial: Mercury worries lead to regulatory worries

Mercury is regulated as a pollutant by the Environmental Protection Agency and the Oregon Department of Environmental Quality.

Published on September 27, 2018 8:39AM


In Victorian England, mercury compounds were used to process felt for hat making.

Mercury is a neurotoxin. Daily exposure to the vapors led hat makers to tremble and to appear insane. Thus was born the now somewhat archaic phrase, “mad as a hatter.”

Today, mercury could soon start driving Oregon farmers and foresters more than a little crazy.

Natural resource industries are worried about the potential regulatory implications of a study identifying forests and farmlands as major sources of the mercury pollution in the Willamette Basin.

Mercury is a naturally occurring element. Readers of a certain age will recall being allowed to play with “quicksilver,” the form of mercury once found in thermometers, in junior high science class. The discovery of mercury in a science classroom today would present an environmental hazard that would require immediate and expensive remediation.

Mercury poisoning is serious business, so it is regulated as a pollutant by the Environmental Protection Agency and the Oregon Department of Environmental Quality.

At issue is mercury that is absorbed by fish, then subsequently ingested by humans who eat fish.

Though mercury can be found naturally in some soils, the real culprit is mercury pollution caused by the burning of coal, particularly for the generation of electricity.

Mercury emissions are severely regulated in the United States, while the Chinese burn coal like crazy to generate electricity without regard to the environmental impact. The main source of mercury in soil and water in Oregon is Chinese power plants.

Atmospheric deposition is estimated to contribute 34 percent of the Willamette Basin’s mercury load, while sediment contributes about 43 percent. Much of the mercury in that sediment comes from historic atmospheric deposits.

The Clean Water Act requires that sources of mercury pollution be identified and regulated.

Regulators in the United States can’t prevent the Chinese from burning coal and can’t stop it from literally raining down on the Pacific Northwest. They can regulate domestic sources of pollution, no matter how minor — such as soil containing trace amounts of mercury eroding into waterways as a result of agriculture or timber harvesting.

DEQ’s modeling estimates forestland represents 45 percent of the mercury load source, followed by shrubland at 20 percent. Row crops represent 7 percent, while the “other” category — which includes pasture and hay ground — was estimated at 11 percent. Altogether, these sources represent 83 percent of the mercury load.

Farmers and foresters do not cause any mercury contamination in soil. Because it is impossible to eliminate all soil erosion, some mercury enters streams through farm and forest practices. Even if it were possible to stop all erosion, no one thinks that it could be enough to reduce contamination to desired levels.

The EPA and DEQ are under court order to adopt more strict methods of identifying and dealing with source pollution. Farmers and foresters rightly worry that they will be held to a standard that they cannot meet.

We can only hope common sense prevails. But that would be a refreshing surprise.



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