Eight out of 10 swordfish samples randomly purchased in northern California and southern Florida supermarkets had mercury levels that exceeded the federal action level, according to the company that conducted the tests.
Micro Analytical Systems (MASI) of San Rafael, Calif., purchased 142 samples of tuna, swordfish and halibut at 19 supermarkets in November and December last year. Of the 41 swordfish samples it tested, 80 percent exceeded 1 part per million of mercury, the U.S. Food and Drug Administrationâ??s ''action level.'' Only 5 percent of the 63 yellowfin tuna samples and 5 percent of the 38 halibut samples exceeded the FDAâ??s mercury threshold.
''We purchased the fish just as any consumer would, selecting these species because they are popular and known to have a higher mercury content than most fish �" swordfish is known to have one of the highest average mercury levels,'' said Mal Wittenberg, MASIâ??s CEO, in a press release.
''Everyone agrees that it is beneficial to eat more seafood, and consumers should be able to enjoy popular fish like tuna, halibut and swordfish, but many consumers also are concerned about mercury,'' added Wittenberg. ''Consumers need to have the information to make informed choices about how frequently and in what quantities they can reasonably consume certain species of fish. We believe if consumers have more confidence in seafood, they will enjoy it more frequently, and that is our goal.''
The average mercury level for all the swordfish samples was 1.63 ppm, while the average levels for the tuna and halibut samples were .477 ppm and .314 ppm, respectively. The seafood in the test was randomly purchased from supermarkets at intervals of three days or more to allow for product turnover. It was tested within 24 hours after purchase using technology with mercury-detection sensitivity close to 10 parts per billion.
MASI has conducted more than 50,000 mercury tests in the past three years in U.S. seafood processing plants and around the world. MASI certifies seafood tested to be lower in mercury through its Safe Harbor Certified Seafood® seal.
Methylmercury is a neurotoxin that accumulates in long-living, predatory fish such as swordfish, shark, tilefish and king mackerel. Methylmercury has been linked to delayed fetal development and health problems in adults, such as kidney damage.
