By HAROLD BROWN

Children can produce a remarkable horse drawing from a numbered, connect-the-dot outline, but confusion reigns when dots are missing or numbers are missing. Watching the efforts of activists to link mercury from electric power plants to danger to unborn babies of pregnant mothers is much like watching a confused young “artist” try to make sense of unnumbered dots.

Try connecting the dots between coal-burning plants and mercury deposition.

Power plants in Pennsylvania, Illinois, and Indiana burned 75 percent more coal, averaging 53 million tons per state per year in 2002-04 than those in Florida, Georgia, and North Carolina, which averaged 30 million tons per state.

The Northern plants emitted nearly twice as much mercury as the Southern states. But mercury deposited in rain averaged 61.6 pounds per 1,000 square miles in the Northern states, 29 percent less than in the Southern states.

Then there’s the missing link between federal Environmental Protection Agency (EPA) estimates of mercury deposition in eastern states and mercury in fish. In 13 states with less than 64 pounds of mercury deposited per thousand square miles in 1994, mercury in largemouth bass averaged 0.53 parts per million from 1990-1995. In 11 states where deposits were higher, bass had only one-half as much mercury.

A Web page by the U.S. Geological Survey gives “geochemical” mercury concentrations (mostly of stream sediments) for Georgia counties. Samples in North Georgia counties averaged three times more mercury than Coastal Plain counties (excluding Glynn County, which was highest in Coastal Plain counties by almost 10 times), yet mercury in bass is two-and-a-half times higher in Coastal Plain streams.

If mercury in fish cannot be connected to mercury in stream sediments, how can the mercury in the blood of mothers who eat fish be connected to mercury in coal smoke?

Mercury in fish may pose a danger to unborn babies in some parts of the world, but not here. The EPA set the “safe level” of mercury at 5.8 micrograms per liter (µg/L) in mothers’ blood — 10 times lower than the threshold at which neurological damage in fetuses begins to appear. And further 58 µg/L represents a lower level of uncertainty about the “real” threshold (85 g/L) in pregnant women in the Faroe Islands. Thus the so-called “safe level” is set at least 14 times lower than the level that causes neurological effects in unborn children.

Women in the Faroe Islands study that EPA used to establish mercury toxicity had a median concentration of 24.2 µg/L in the blood. The average for 3,637 American women in 1999-2002 was 0.92 µg/L, less than 4 percent of the average for Faroe Islands women. None of the U.S. women had levels as high as the threshold set by EPA; fewer than 6 percent had levels above the “safe level” of 5.8 µg/L.

The main cause of high mercury levels in Faroe Islands women was consumption of whale meat. Would it be the same for a diet of hamburgers, salads, or broiled bass? Not likely! Health officials have never documented a single U.S. case of damage to unborn babies from mercury in fish, and statistical connections have been vague and inconclusive.

There are two good reasons for this: Diets of American mothers don’t cause high levels of mercury in the blood, and most studies of mothers elsewhere with high mercury have found no effects on babies. In fact, studies of 700 to 800 women in the Seychelles Islands found mercury levels were 40 percent higher than the Faroe Islanders’ — with no effects of mercury on neurological development. In fact, in some of the Seychelles’ tests development was better with increases in mercury, perhaps reflecting the benefits of increased fish in the diet.

Mercury is decreasing in the environment and probably in American women. Summaries of blood mercury in American women by the Centers for Disease Control and Prevention (CDC) indicate decreases from 1999 to 2002, but the CDC concluded that “the declines were not statistically significant” from the first two years of study to the second two.

They also stated, “At least 2 more years of data are needed to best determine whether Hg (mercury) exposure has declined among women of childbearing age in the United States.”

Yet the survey did not continue. If this agency has a “consensus” on the need for strengthening controls over mercury emissions, perhaps the its consensus is trending in the wrong direction.

The dots representing mercury in fish and people, health effects, power plants and regulation are scattered across the landscape and badly numbered. That hasn’t stopped the bold freehand of government agencies and environmental “push” groups from conjuring up a unicorn and trying to convince us it’s a horse.

University of Georgia Professor Emeritus R. Harold Brown is an adjunct scholar with the Georgia Public Policy Foundation and author of “The Greening of Georgia: The Improvement of the Environment in the Twentieth Century.” The Georgia Public Policy Foundation is an independent think tank that proposes practical, market-oriented approaches to public policy to improve the lives of Georgians.

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