In March the FDA expanded its mercury warning label on fish and shellfish to include tuna. Ironically, at the same time one government agency is working to keep people healthy by minimizing the amount of mercury we eat through these fish, another government agency is actively working in the other direction. What we have forgotten to ask in the midst of this great debate is how did the mercury ended up in the ecosystems for fish to ingest in the first place? Is mercury poisoning from tuna a real possibility? As one Dirt! reader commented " A good dear friend of mine actually got mercury poisoning and was nearly dead because he ate so much tuna. So, this IS very real, very sad." As Bill Moyer explored in his special on mercury in fish, people can achieve eating the amounts recommended by the EPA (then in July, 2003) in quantities much sooner than they might think.

What is up with Mercury? Where can it be found it naturally? Mercury rarely occurs "free" as a chemical in nature. Mainly it is found bonded to other minerals in cinnabar ore from Spain and Italy. The metal is extracted by heating cinnabar in a current of air and condensing the vapor. One of the interesting facts about mercury is that it easily forms alloys with many metals, such as gold, silver, and tin and as such, has been used to make amalgams (like those fillings in your teeth) since 500 BC. One of the substances it also can form that is toxic to humans is methylmercury. It is this that is found in varying quantities in fish. So despite all the health benefits that are also associated with eating fish, be wise and eat in moderation.

What are major sources of mercury in our environment? A recent letter to the editor in the Philadelphia Enquirer claimed "The largest unregulated source is coal-fired power plants, which emit mercury through their smokestacks. It then falls into water, where it's absorbed by algae, which is eaten by fish. Forty-four states, including Pennsylvania and New Jersey, report excessive mercury in their freshwater lakes and streams."

What are effects of mercury in humans? Mercury is a toxin, and serves no beneficial purpose in anyone's body. Exposure can cause learning disabilities and neurological damage in children and developing fetuses. This is why pregnant women, women who may become pregnant, nursing mothers and young children are especially warned away from eating too much seafood - especially "higher level" fish like shark, swordfish, king mackerel, tilefish should be avoided. These fish are predatory in nature, eating other fish and therefore the levels of mercury found in their bodies accumulates at a greater level than in smaller fish. Tuna is also predatory type of ocean fish. Women and young children are advised to limit their intake of white albacore tuna to six ounces per week. Everyone else can continue to eat tuna and other kinds of fish - in moderation. Besides mercury, there are other reasons to avoid eating large quantities of any one type of fish such as endangering a species or threatening a rare habitat. The Chefs' Collaborative publishes a list of what types of seafood conscious caring consumers might want to avoid. Much smaller and drabber, these are easy to overlook."

What are possible solutions? What can we do? There are several things we can do to tackle this problem. Of course the most effective solutions will come if we take a multi-faceted approach. Of course, on a personal level, (1) we can limit our own intake of tuna. A bigger issue however, gets lost in the confusion over what to eat or not to eat. Industrially generated mercury pollution needs to be removed from the environment so it does not get into fish in the first place. This is where the effort to protect consumers first fails. (2) We can keep up the pressure to support strong government regulation. Mercury emissions are currently unregulated in the United States. The EPA began a process to develop a regulation several years ago. This rule is expected to be adopted in March 2005. Finally, (3) we can move toward cleaner energy production (wind, solar, geothermal, water). By choosing "Salmon Safe" energy alternatives like the ones offered by PGE we are actually helping create a new energy industry that is not dependent on coal. Choices like these on a local level have the potential to make a huge impact globally.

Additional Resources

Chefs' Collaborative

Environmental Protection Agency

NOW with Bill Moyer

FAQ Sheet on Mercury