News outlets from Pennsylvania to Pakistan are reporting that fish bought in U.S. grocery stores contain “dangerous” levels of methyl mercury and should carry warning labels. The source for this alarming news? A report issued by professional scaremongers at Oceana and the Mercury Policy Project. “A typical shopper,” the groups’ press release claims, “has a 50 percent chance of buying a swordfish steak with mercury levels considered unsafe by the FDA.” And a similar fate awaits anyone who enjoys a grilled ahi tuna steak, according to the activists. That truly would be scary news — if it were true.

As we explained to the media last week, this report relies on the Food and Drug Administration’s artificially low “action level” for mercury in fish. The FDA itself has written that its action level:

… was established to limit consumers’ [lifetime] methyl mercury exposure to levels 10 times lower than the lowest levels associated with adverse effects … [and] is considerably lower than levels of methyl mercury in fish that have caused illness.

Translation: there’s a safety factor of ten built into the FDA’s standard. So even if the mercury in a given fish were double the FDA’s action level, the purchaser’s health would still be protected by a five-fold safeguard.

Balancing the scales this week is welcome news from the International Association of Fish Inspectors, whose annual meeting just concluded in Australia. In a news release from the event, University of Florida Professor Steve Otwell said:

[F]or most people, the health benefits far, far outweigh any possible risk… do not stop eating fish. That would do more harm than good.

This kind of common sense isn’t likely to prevail at this week’s Environmental Protection Agency (EPA) National Forum on Contaminants in Fish, since the EPA continues to actively promote its mercury reference dose. Like the FDA’s “action level,” the EPA’s dose includes an arbitrary 1,000-percent “uncertainty factor.” So if you’ve heard government advisories telling pregnant women to cut back on their tuna consumption, and activist groups like the Environmental Working Group recklessly warning you not to exceed supposedly “safe” levels of fish in your diet (in spite of the undeniable heart-health benefits of fish and other foods high in omega-3 fatty acids), you should know that their rhetoric is all based on this artificially low “reference dose.” The bottom line: Americans are being needlessly scared about exceeding a dose that’s just 10 percent of the level that might be a cause for concern.

Professor Otwell is right to warn against the hype. And the more than 30 activist groups who are aggressively campaigning — and raising millions of dollars along the way — to raise red flags over this giant red herring (see here, here, here, here, and here for additional examples) have some serious explaining to do.