The Problem With Mercury: Pervasive, Perilous and Persistent

BUZZFLASH NEWS ALERT
by Margaret Smith

You can't fry it out. You can't bake it out. You can't fillet it out.

While a new government study shows how pervasive mercury contamination is in our waterways, what might surprise you is what it does to the human body. At high levels the contaminant can affect the central nervous system and irreversibly damage areas of the brain.

The scary part, though, is how hard mercury is to get rid of. For humans, it takes 70 days for half the body burden of mercury to be eliminated from the human body. And that's if you manage to not eat any during that time.

A national report released last Wednesday by the U.S. Geological Survey (USGS) found that traces of mercury were detected in every fish tested in nearly 300 streams across the United States, a figure that shows just how widespread the contaminant is in our environment today.

From 1998 to 2005, over a thousand fish were collected and tested in 291 streams nationwide. The results? Every fish was contaminated, and about a quarter of those sampled were found to contain mercury levels that exceeded those set by the U.S. Environmental Protection Agency as safe for people eating average amounts of fish. According to the USGS, 33 states have issued fish consumption advisories because of mercury contamination.

"This study shows just how widespread mercury pollution has become in our air, watersheds and many of our fish in freshwater streams," said Secretary of the Interior Ken Salazar in a statement. "Science sends a clear message that our country must continue to confront pollution, restore our nation's waterways and protect the public from potential health dangers."

Many of the highest mercury level concentrations in fish were found in the dark-colored, or "blackwater", streams that run through relatively undeveloped forests and wetlands in the Eastern and Southeastern United States, such as Georgia, Florida, Louisiana and North and South Carolina. High levels of mercury in fish were also found in more undeveloped watersheds in the Northeast and Upper Midwest, as well as streams along the West Coast that have been contaminated by mining.

Mercury is one of the most serious contaminants threatening our nation's environment. Much of it is released into the country's natural waters by mercury that is emitted into the atmosphere, mostly from emissions by coal-fired power plants, which is then deposited in the water through rainfall. Best estimates released by the USGS show that to date, human activities have approximately doubled or tripled the amount of mercury in the atmosphere, and that number is increasing by 1.5 percent each year.

We generally process mercury in two ways: by breathing in vaporous mercury and by taking it in through fish consumption in its toxic form, methylmercury. The human body is already adapted to processing vaporous mercury. When mercury is mixed in the water through rainfall, natural processes convert it into methylmercury. This form can be taken in by fish, and then starts winding its way up the food chain.

At the current levels in our environment however, many adults may only experience a milder case of mercury poisoning that can result in reductions in motor skills and a dulled sense of touch, taste and sight.

Those at the greatest risk, however, are unborn children. Recent research from the USGS suggests that prenatal effects of mercury occur at intake levels 5 to 10 times lower than the average adult, which may result in learning disabilities.

While the current mercury poisoning levels are still low enough to avoid significant harm, it isn't an empty threat. In the past, mercury poisoning has caused severe community disasters. The worst cases are from an agricultural disaster in Iraq in 1971 and an industrial release in Minamata Bay, Japan in 1956. In each case, hundreds of people died and thousands were affected, many with permanent brain and nervous system damage. 

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