Yesterday Canada’s national public health agency adjusted its standards for trace levels of mercury in several kinds of fish. Based on recent science (click here, here, and here) that firmly placed fear of fish in the same category as other irrational phobias, we expected our neighbors to the north to encourage increased seafood consumption. Instead, Health Canada created new confusion by preaching strict limits on the consumption of a half-dozen fish species. True, the agency hedged its bets by allowing that "most Canadians do not need to be concerned about mercury exposure from eating fish." But this nuance will likely be lost on much of the public, who will be more frightened to put fish on their dinner plate in general. And that’s decidedly bad for public health.

Canada’s maritime economy relies on seafood as a big part of its gross national product, so an edict to lay off the orange roughy and tuna sushi is unexpected, to say the least. Nevertheless, we’re seeing the hand of a native Canadian scaremonger in all of this. Donna Mergler, a University of Quebec at Montreal environmental scientist, chaired a panel on the "Health Risks and Toxicological Effects" of mercury at an August 2006 mercury conference in Madison, Wisconsin (click here, here, here, here, and here to get caught up). And a few weeks ago when this conference finally got around to publishing its findings, Mergler was front-and-center predicting that fish in the diet of pregnant women would negatively "affect children’s development later on in life." Mergler even called for mercury warning labels on cans of tuna.As we pointed out a few weeks ago, in the months between the August conference and the March "Madison Declaration" from Mergler and her colleagues, a wealth of science has emerged that completely takes the wind out of their panic-stricken sails. But they chose to completely ignore it. So has Health Canada. Instead of embracing scientific reminders that fish is a health food, the agency has sounded the latest in a series of needless alarms.

It’s hard to believe that an entire country’s public-health sector could be so myopic. But then again, ours isn’t much better. The U.S. Environmental Protection Agency could easily scrap its flawed "Reference Dose" for fish-borne mercury in favor of a more real-world approach that balances hypothetical risks with proven health benefits. There’s certainly enough scientific evidence to justify such a move, and it would be a huge improvement. Scaring people away from fish (on either side of the border) certainly won’t make them any healthier.