Mercury in Fish Another Overblown Issue

Today I read two somewhat contradictory stories in my local paper about mercury levels in fish, and to what extent this is a health hazard for us. The first (originally from Washington Post, but see it here) describes a recent report that suggests some areas are more susceptible to mercury pollution than others, describing these areas as mercury "hot spots". As a report about a report, it seemed like a fine article I suppose. But what it lacked was any mention of why we should care much about the issue. It just took it for granted that everyone knows that mercury-in-our-fish is a bad thing. And that is probably making a safe assumption on the part of readers, since we have been bombarded with stories of how dangerous mercury found in our fish diets can be for our health.

But the story gets very much complicated by the second, shorter article I read today. In the USA Weekend supplement to my local paper, the "Eat Smart" column by Jean Carper was titled "Phony Fish Scare?". Here it is in full:

Don't let a mercury scare keep you from eating fish, says William Lands, Ph.D., formerly with the National Institutes of Health and a leading expert on the benefits of fish oil. He says virtually all fish, even those high in mercury, are safe.

"Mercury is toxic in the absence of selenium," Lands says, "but fish is loaded with selenium that neutralizes the danger." A new University of North Dakota study shows that common fish, including grouper, swordfish, tuna and salmon, have much more selenium than mercury. Even albacore tuna (high on the government's hit list) has 15 times more selenium than mercury, making it perfectly safe, in Lands' view.

Is there any fish Lands would avoid because of high mercury? No, except maybe the pilot whale, not seen in U.S. markets.

So that was eye-opening for me. Selenium, which is common in fish, counter-acts the dangers from mercury.

So I did a little looking around the web, and I found several interesting things. The first was this article, which has an interesting excerpt including a graph showing the relative levels of mercury and selenium in various types of fish, and also in pilot whale -- the mammal mention by Lands above. Very interestingly, there are far greater levels of selenium than mercury in all the fish species shown: sole, flounder, salmon, tuna, pollock, halibut, cod, snapper, grouper, and swordfish. But in the case of pilot whale, the relative amount of selenium is much lower than in all the types of fish listed.

The info in the article was taken from materials at mercuryfacts.com, which seems to be the same site as fishscam.com. This site has lots of interesting materials, including critical comments about prominent scientists and environmentalists who are promoting fear of mercury in fish. As just one item on their site, see "The Flip Side of Mercury". One also discovers that much of the health concern over mercury in fish comes from a study that involved... guess what... pilot whale. See also the Mercury Myths page, which details problems with the following common claims:

• The amount of mercury in our environment (and in the fish we eat) is dangerously increasing.
• Mercury in fish presents a serious health risk to Americans.
• The health risk from mercury outweighs the health benefits of eating fish.
• You can get mercury poisoning from the amount of fish you might consume in a given week or month.
• Every year in the United States, 630,000 children are born with mercury levels in their blood that put them "at risk" for neurological disorders later in life.
• Eight percent of American women of childbearing age have unsafe levels of mercury in their blood.

Apparently there is good reason to doubt each of these claims.