The latest indication that our current paranoia about mercury has gotten out of hand is the conference that was held this week in Madison devoted to all things quicksilver. Participants debated the impact of mercury pollution and discussed how much the human body is built to handle.

As scientists and government regulators talk turkey and environmental activists spin the results, news reports will cast a gloomy pall over fish consumption. And ordinary people will be seriously misled.

Americans hear about mercury because small amounts of it are emitted into the air when gold is mined and coal is burned to generate power. And minute traces of the stuff are (and have always been) in the fish we eat.

While U.S. fish consumption lags far behind that of countries like China and Japan, we still recognize that fish bring enormous health benefits to our dinner tables. Omega-3 fatty acids, plentiful in most fish, can head off conditions like heart disease, breast and prostate cancer, kidney disorders and Alzheimer’s disease.

How tiny are the traces of mercury in fish? University of Rochester scientists report in the New England Journal of Medicine that there haven’t been any clinical reports of fish-related mercury poisoning since the 1950s and 1960s.

Those cases involved massive fish contamination from chemical spills in Japanese waterways. By comparison, the parts-per-million mercury measurements in today’s fish are practically inconsequential to human health. As toxicologists like to say, it’s the dose that makes the poison.

The Food and Drug Administration has established an advisory level for mercury in fish, called an “action level.” Environmental activists are fond of sounding the alarm whenever this magic number is breached, claiming proof of “contaminated” fish and “endangered” consumers. But the FDA’s mercury action level has a built-in safety cushion of 1,000%.

While very few fish test above the action level, there’s no cause for panic unless the fish exceed it 10 times over, reaching what the FDA calls “the lowest level associated with adverse effects” to human health – a level derived by studying the Japanese poisoning cases.

In May, the Center for Consumer Freedom bought 142 pieces of fish from all around Madison. We visited the Willy Street Co-op, Whole Foods, Hughes Seafood, Mariner’s Inn, Blue Marlin, Ocean Grill, Restaurant Muramoto, Sushi Box, Nau-Ti-Gal and 28 other restaurants and retailers.

An independent laboratory tested 17 different fish species, plus canned light and albacore tuna. Only our five swordfish samples exceeded the FDA’s mercury action level. And the highest level was less than 35% of the real harm threshold. That’s the tenfold safety factor at work.

Environmental groups have generally kept the public in the dark about the safety cushions included in mercury advisory levels. Food scares, after all, make for good fund raising and sensational newspaper headlines. They also don’t say much about the good-news research that undercuts our societal fear of mercury.

There’s growing evidence, for example, that the nutrient selenium – which is plentiful in fish – protects the human body from mercury. The World Health Organization has recognized since at least 1990 that selenium “protects against the toxic effects” of mercury. And this year, noted selenium scientist Nicholas Ralston declared that ocean fish “are uniformly rich in selenium and therefore protect humans from any mercury toxicity” from fish consumption.

Every fish species we tested in Madison averaged more selenium than mercury. In 12 species, the ratio was more than 10 to 1.

Two of the three most recent former U.S. secretaries of health and human services are now openly advising Americans to eat more fish. But environmental advocates will emerge from the great Madison mercury huddle with advice consisting of warning signs on what our mothers used to call “brain food.”

We’d do well to ignore them.