[RE: “Know Your Ingredients,” April 15-21]: Gwyneth Doland is a competent food editor. Unfortunately, she is not very well informed about mercury, and her recent claims about that metal prove it, for she appears to know nothing about the well-established facts concerning mercury.
Doland claimed that coal-fired plants "spew" mercury into the air. It is generally agreed that coal-fired plants emit 50 tons of mercury into the air per year. There are approximately 447 coal-fired plants in the United States. Some quick arithmetic will show that this is about 280 pounds of mercury for all plants per day, or an average of about 10 ounces of mercury per plant per day. (The amount per day varies depending on the size of the plant and the grade of coal it is burning.) Nevertheless, at this rate mercury is not “spewing” (gushing) out of the smokestacks of coal-fired power plants.
For additional perspective, the EPA estimates that there are 158 tons of man-made mercury emissions per year in the United States, so coal-fired plants account for only about one-third of U.S. emissions. Annual world-wide mercury emissions amount to some 5,000 tons, so U.S. coal-fired plants contribute a mere 1 percent of yearly world-wide mercury emissions.
Doland wrote that there is a move afoot to "play down the established link between coal-burning power plants and dangerous levels of mercury in the nation's fish." Since there is no such "link," to that extent this assertion is false. Doland referred to a New York Times article that stated that the National Academy of Science said that the White House (the Bush administration) is trying to "play down" mercury's dangers. Somewhere along the line, this is probably false as well. The dangers of mercury are universally known, and it would be as easy to "play down" the dangers of mercury as it would be to "play down" the dangers of drunk driving.
The article also claimed that the mercury particles from power plants "fall close to the source" (close to the plant) and then are carried into rivers and streams. This is debatable. Mercury transport in the upper atmosphere, and its deposition, are poorly understood. A little more to the point, and in keeping with Doland's recommendations for fish consumption, these particles would be ingested by fresh water fish. What fish are we advised by Doland to not eat? They are shark, swordfish, king mackerel, tilefish and tuna—all salt water fish.
No one disputes the dangers of consuming methylmercury, the dangerous form of mercury that is found in fish. What is under dispute is the likelihood of danger to humans. It appears that the only known case of mercury poisoning from eating fish occurred in the '50s near Minamata Bay in Japan. According to Gary Myers, M.D., a professor of neurology and pediatrics and member of the University of Rochester (N.Y.) Research Team that studied the effects of methylmercury, there have been no reports of anyone suffering mercury poisoning from eating fish since the poisonings in Japan in the '50s and '60s. (There have been some other cases of mercury poisoning, but they were not from eating fish.)
Consumers who are worried about mercury poisoning should limit their consumption of fish, and comply with fish advisories. If Doland wants to warn us about the possible dangers of the food we eat, that is her prerogative. But Gwyneth, in the future why not obtain a broader perspective on your subject instead of succumbing to hysteria?