Methylmercury in dried shark fins and shark fin soup from American restaurants

• Published in: The Science of the total environment Vol. 496; pp. 644 - 648
• Main Authors: Nalluri, Deepthi, Baumann, Zofia, Abercrombie, Debra L., Chapman, Demian D., Hammerschmidt, Chad R., Fisher, Nicholas S.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.10.2014
• Subjects: Animal Fins - chemistry; Animals; Consumers; Diet - statistics & numerical data; Environmental Exposure - statistics & numerical data; Exposure; Fins; Food; Food Contamination - statistics & numerical data; Human; Humans; Marine; Mercury; Mercury (metal); Methylmercury Compounds - analysis; Public health; Restaurants; Restaurants - statistics & numerical data; Seafood - analysis; Seafood - statistics & numerical data; Shark fin soup; Sharks; Soups; Sphyrna; United States; Water Pollutants, Chemical - analysis; United States; USA; Shark fin soup; Mercury; Public health; Food
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2014.04.107

Consumption of meat from large predatory sharks exposes human consumers to high levels of toxic monomethylmercury (MMHg). There also have been claims that shark fins, and hence the Asian delicacy shark fin soup, contain harmful levels of neurotoxic chemicals in combination with MMHg, although concentrations of MMHg in shark fins are unknown. We measured MMHg in dried, unprocessed fins (n=50) of 13 shark species that occur in the international trade of dried shark fins as well as 50 samples of shark fin soup prepared by restaurants from around the United States. Concentrations of MMHg in fins ranged from 9 to 1720ng/g dry wt. MMHg in shark fin soup ranged from <0.01 to 34ng/mL, with MMHg averaging 62±7% of total Hg. The highest concentrations of MMHg and total Hg were observed in both fins and soup from large, high trophic level sharks such as hammerheads (Sphyrna spp.). Consumption of a 240mL bowl of shark fin soup containing the average concentration of MMHg (4.6ng/mL) would result in a dose of 1.1μg MMHg, which is 16% of the U.S. EPA's reference dose (0.1μg MMHg per 1kg per day in adults) of 7.4μg per day for a 74kg person. If consumed, the soup containing the highest measured MMHg concentration would exceed the reference dose by 17%. While shark fin soup represents a potentially important source of MMHg to human consumers, other seafood products, particularly the flesh of apex marine predators, contain much higher MMHg concentrations and can result in substantially greater exposures of this contaminant for people. •Concentrations of monomethylmercury (MMHg) in fins and soup varied among shark species.•MMHg was highest in fins and soup from large, high trophic level sharks.•Estimated human exposures to MMHg from shark fin soup are relatively low.