Thursday, January 8, 2009

Hg. Mercury is natural and all around us.

Myth: The amount of mercury in our environment (and in the fish we eat) is dangerously increasing.

The truth: There's considerable evidence that the amount of mercury in fish has remained the same (or even decreased) during the past 100 years.

One team of researchers from Duke University and the Los Angeles County Natural History Museum compared 21 specimens of Atlantic Ocean blue hake preserved during the 1880s with 66 similar fish caught in the 1970s. They found no change at all in the concentration of mercury.

In another study, Princeton scientists compared samples of yellowfin tuna from 1971 with samples caught in 1998. They expected to find a mercury increase of between 9 and 26 percent, but they found a small decline instead.

And in a unique experiment, curators of the Smithsonian Institution tested tuna samples that were archived between 1878 and 1909, and compared them with similar fish tissue from 1971 and 1993. They found significantly less mercury in the more recently caught fish. In some cases, the difference was more than 50 percent.

There's even some evidence that human beings are exposed to less mercury today than in the past. Alaska's Public Health Department, for example, reports that when the hair of eight 550-year-old Alaskan mummies was tested for mercury, the results showed levels averaging twice the blood-mercury concentration of

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