Mercury Found in Fish at Grocery Stores Across the US
- Photo courtesy: NOAA, Jose Cort
Oceana and the Mercury Policy Project released the results of a major 22-state mercury testing project, confirming that store-bought swordfish and tuna contain levels of mercury that the federal government has determined may be hazardous to human health, particularly children.
Read the full report, Fair Warning: Why Grocery Stores Should Tell Parents About Mercury in Fish (pdf).
Read the press release.
Key Findings
- The average mercury concentration for the swordfish samples was 1.11 ppm. The samples ranged from 0.41 ppm to 2.33 ppm. The average exceeds the FDA action level of 1 ppm. Additionally, 50% of the swordfish samples collected exceeded the FDA action level.
- The mercury concentration in 31 samples of fresh or frozen tuna ranged from 0.09-0.68 ppm and averaged 0.33 ppm. The average mercury level for these fresh tuna samples is comparable to the levels found in canned albacore tuna. The 2004 FDA/EPA advisory specifically warns that women of childbearing age and children should limit consumption of canned albacore tuna.
- A 44 pound child consuming 6 ounces of tuna a week at this mercury concentration would be exposed to 4 times the EPA reference dose for mercury.
- A 120 pound woman consuming 6 ounces of tuna a week at this mercury concentration would be exposed to one and one half times the EPA reference dose
Why is This Study Important?
- These fresh tuna data underscore an important, but underemphasized point in the 2004 FDA/EPA advisory, which advises limiting consumption of tuna steaks to 4meals a month. This information is buried in the Q&A section on the second page of the EPA/FDA warning.
- Similar monitoring of fifty New Jersey storebought fresh tuna steaks in 2003 revealed mercury levels in fresh tuna ranging from 0.08-2.5 ppm and averaging 0.6 ppm.* Together these two studies emphasize that more systematic government monitoring is warranted and necessary.
About the Study
- Fish were collected from stores in 22 locations including: Alaska, California, Connecticut, Washington DC, Florida, Idaho, Illinois, Louisiana, Massachusetts, Maryland, Maine, Michigan, Minnesota, Montana, North Carolina, New Hampshire, Oregon, Pennsylvania, Rhode Island, Texas, Vermont and Wisconsin.
- Fifty-five swordfish and tuna samples were tested for mercury content at the University of North Carolina Environmental Quality Institute laboratory between the dates of July 7, 2005 and August 11, 2005.
- This project analyzed and reported on mercury levels in 24 swordfish samples. This is 6 times more swordfish samples than FDA has released mercury data for in the past 5 years.**
- The FDA has released mercury data for only 4 samples of fresh or frozen tuna since 1997. This project has analyzed and released data for nearly 8 times more fresh tuna samples than FDA has in the past 8 years.
*Burger, J., A.H. Stern and M. Gochfeld. 2005. Mercury in Commercial Fish: Optimizing Choices to Reduce Risk. Environmental
Health Perspectives 113(3):1-6.
**According to most recently publicly available data. FDA, Mercury in Fish: FDA Monitoring Program (1990-2003). Available at:
http://www.cfsan.fda.gov/~frf/seamehg2.html