It would be a mistake to overreact to the results of mercury testing carried out on Gulf seafood by the activist group Oceana. [“Scientists track fish mercury levels,” Feb. 20]. The Food and Drug Administration’s “Action Level” for mercury in fish, which environmental groups often wrongly call a “legal limit,” is just an advisory level and has a safety factor of 10 built-in.

This means that an individual piece of fish would have to exceed the FDA’s Action Level by 1,000 percent before it could be considered unsafe to eat. By its own reckoning, Oceana didn’t find a single fish that tested anywhere near this high for mercury. And the theoretical risks from trace amounts of mercury in fish would take an entire lifetime to accumulate anyway.

Given all we know about the healthfulness of eating fish, there’s a real danger of Americans (especially women) being scared away from eating fish by green groups that lack a good understanding of science. Fish is still the good-for-you “brain food” that our mothers encouraged us to eat. But needless anxiety about mercury may indeed be hazardous to your health.