Mercury Series

Published December 16, 2005

To the Editor:

Your three-part series on mercury in fish [“The Mercury Menace,” December 11, 12, 13] left out five key facts.

First, if the micro-traces of mercury in fish sold in supermarkets of Chicago are truly so harmful as you portrayed them to be, then it is puzzling that you are unable to find even a single case of fish-mercury poisoning in Chicago. You report anecdotal evidence for the “poisoning” of Sophie Chabon, of Berkeley, California, but the fact that her symptoms apparently were reversible suggests she was not suffering from any known kind of methylmercury poisoning.

Second, your report of EPA’s “safety” standard for fish mercury to be 0.1 grams of mercury per kilogram of body weight each day is incorrect. The level actually is 0.1 micro-grams, one million times smaller than you indicated.

Third, your articles failed to recognize that EPA’s “safe” mercury standard is the most stringent in the world. In the latest survey of more than 5,900 Japanese, 87 percent of the sample had mercury levels above EPA’s standard. Another new survey found 56 percent of Inuit cord blood samples exceeded EPA’s “safe” level.

Fourth, your feature of the “peer-reviewed study” by Dr. Jane Hightower failed to report the puzzling and highly inconsistent scenario that the more red snapper and sole her patients ate the lower their blood mercury levels were! This is a clear case of a bad study with little or no control sample.

Finally, your investigation implies that high levels of mercury in tuna are only a recent phenomenon. In fact, a recent study of yellowfin tuna from Hawaii by scientists from Princeton University found no increase in mercury levels for tuna sampled between 1971 and 1998. The authors concluded, “the unchanging mercury concentration in tuna caught near Hawaii provides prima facie evidence that this concentration is not responding to anthropogenic emissions irrespective of the mechanisms by which mercury is methylated in the oceans and accumulated in tuna.”

The bottom line is that the beneficial effects of eating fish far outweigh the newly invented fears about mercury in fish. Additional research on this issue can be found at

Willie Soon ([email protected]) of the Center for Science and Public Policy in Washington, DC.