Eating seafood high in mercury is hazardous to your health, especially for women and children. The "Got Mercury?" calculator below helps you make healthier seafood choices. Just enter your weight, the seafood type, the amount of seafood you will eat during a week, and click the calculator button. These calculations are based on EPA and FDA data (updated January 2006).
Eating more than one type of fish per week? Use the ADVANCED CALCULATOR.
 How many ounces of seafood is a typical portion? You can use the following estimates: A typical serving of fish (steak or fillet) is about 6 to 8 ounces. A sushi order is 2 to 4 ounces per type. A standard can of tuna contains 6 ounces<<br />
How can I enter grams & kilograms? 1 kilogram = 2.2 pounds. 1 gram = 0.0353 ounces.
GotMercury.org in Spanish - Calculadora de mercurio en mariscos en Espaņol:www.gotmercury.org/espanol
Mercury contamination of seafood is a widespread public health problem. The Food and Drug Administration warns that pregnant women, nursing mothers, women who might become pregnant, and children should not eat swordfish, shark, tilefish, and king mackerel because of their high methylmercury content. The FDA also warns women and children to limit their consumption of tuna.
Seafood low in mercury can be part of a healthy diet. However, seafood consumers should eat a variety of fish low in mercury and should have a balanced diet.
Facts for Fish Eaters
Why isn't my fish listed in the calculator? This list of fish species comes from data published by the FDA. The list contains some of the most commonly eaten species of fish, but is limited to fish the government has tested. Do not assume that unlisted fish are low in mercury or safe to eat. The data used in the calculator are averages from the FDA, but individual fish can be higher or lower. Additionally, some seafood may be low in mercury, but might be high in other contaminants such as PCB's, cadmium or other metals, and other pollutants. For example, there are alarming reports regarding contamination of farm-raised salmon.
What about differences between canned tuna? Most canned tuna is labeled as either "albacore" or "chunk light". There are other species of canned tuna, as well. Albacore tuna, according to FDA data, contains 3 times as much mercury as chunk light (0.353 ppm vs. 0.118 ppm). Cans of chunk light tuna usually contain skipjack tuna, which is a smaller species and averages lower mercury levels. However, a Chicago Tribune investigation found that chunk-light canned tuna sometimes contains yellowfin tuna (0.325 ppm), but is not labeled correctly. Also, a study found that troll-caught albacore mercury levels are lower (0.14 ppm vs. 0.353 ppm) because they are younger than longline-caught albacore. Read canned tuna labels carefully to find out which species it contains! You can compare the mercury levels between all types of tuna in the mercury calculator above.
What about fresh and frozen tuna? Tuna is a popular seafood item. Tuna comes as steaks or, in Japanese cuisine, as sushi or sashimi. In restaurants and stores, tuna is labeled "ahi", the Hawaiian word for tuna, which could be either bigeye tuna (0.639 ppm) or yellowfin tuna (0.325 ppm), both high in methylmercury. Consumers should ask specifically what kind of tuna they are getting. For example, "maguro" and "toro" in sushi restaurants refer to the back or belly of the tuna, not the species. Sushi and sashimi can also be albacore or bluefin tuna.
What about salmon? Salmon has low average mercury levels, according to FDA data. However, the FDA found some salmon with mercury levels as high as 0.19 ppm.
Some more information about your mercury levelsThe EPA reference dose (RfD) is defined as the amount of mercury a person, including sensitive subpopulations, can be exposed to on a daily basis over a lifetime without appreciable risk of effects.
The EPA RfD is 0.1 ĩg mercury per kg body weight per day. When using the mercury calculator at GotMercury.Org, this value (adjusted for a week of exposure) is the value to which your mercury levels are being compared.
This level corresponds to a blood mercury level of 5.8 ug/L or 5.8 parts per billion (ppb) mercury. Blood mercury levels below this value are considered to be without appreciable risk by the EPA.
For hair, the mercury level that corresponds to the RfD is 1 part per million (ppm).
A study by Turtle Island Restoration Network (TIRN) of mercury levels in swordfish found that 68% of the swordfish samples were above the FDA Action Level of 1 part per million mercury and 16% were over 2 parts per million (twice the FDA's Action Level). The average mercury concentration was 1.38 parts per million, which is 38% higher than the FDA Action Level.
The FDA has set an "action level" of 1 part per million (ppm) for seafood. Ironically, the FDA fails to take action when fish in grocery stores or restaurants exceed the "action level" value.
In 2004, a study found that the number of infants that are potentially exposed to dangerous levels of mercury in the womb was 630,000 children in the U.S. annually. This was double the previous estimates and was determined from mercury levels in umbilical cords, which contain mercury levels 1.7 times higher than those of the mother's blood level. Based upon this data, far more babies are being exposed to the reference dose than previously thought.
Most Modern Fishing Practices Are Not Sustainable
Many of the fish species listed in the calculator are overfished, endangered, or being caught using unsustainable fishing methods. If you would like more information about sustainable seafood, please visit the Monterey Bay Aquarium's Seafood Watch or the Environmental Defense's Seafood Selector.
In addition to being toxic for humans, tuna, swordfish, and many other fish are caught in ways that are devastating ocean habitats and fisheries. Longline fishing, the destructive fishing method often used to catch tuna and swordfish, kills thousands of endangered sea turtles per year. Our organization supports responsible and sustainable fishing.
Got questions? Please email Sharon Marchetti at SMarchetti@GotMercury.org
or call 415-663-8590 ext. 109.
* Mercury concentration values used for this calculator come from the United States Food and Drug Administration website (http://www.cfsan.fda.gov/~frf/sea-mehg.html). Two exceptions are the troll-caught albacore data which comes from an Oregon State University study and canned albacore data, which comes from an FDA dataset that is not yet published on their site. Please be aware that these values are averages. The concentration of mercury in seafood can be significantly higher or lower than what is represented here. As a precautionary approach, we recommend that women, (especially of childbearing age) avoid seafood species that contain higher average levels of mercury. Mercury information for many shellfish species is currently unavailable.
design: Steven Lyons photo: Robert Cardin
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