Methylmercury in dried shark fins and shark fin soup from American restaurants.
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 1720 ng/g dry wt. MMHg in shark fin soup ranged from <0.01 to 34 ng/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 240 mL bowl of shark fin soup containing the average concentration of MMHg (4.6 ng/mL) would result in a dose of 1.1 μg MMHg, which is 16% of the U.S. EPA's reference dose (0.1 μg MMHg per 1 kg per day in adults) of 7.4 μg per day for a 74 kg 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.
Department of Earth & Environmental Sciences, Wright State University, Dayton, OH 45435, United States.
Deepthi
D
Nalluri
Department of Marine Sciences, University of Connecticut, Avery Point, Groton, CT 06340, United States. Electronic address: zofia.baumann@uconn.edu.
Zofia
Z
Baumann
School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794-5000, United States.
Debra L
DL
Abercrombie
School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794-5000, United States.
Demian D
DD
Chapman
Department of Earth & Environmental Sciences, Wright State University, Dayton, OH 45435, United States.
Chad R
CR
Hammerschmidt
Department of Marine Sciences, University of Connecticut, Avery Point, Groton, CT 06340, United States.
Nicholas S
NS
Fisher
D058500:Animal Fins / Q000737:chemistry; D000818:Animals; D004032:Diet / Q000706:statistics & numerical data; D004781:Environmental Exposure / Q000706:statistics & numerical data*; D005506:Food Contamination / Q000706:statistics & numerical data*; D006801:Humans; D008767:Methylmercury Compounds / Q000032:analysis*; D012147:Restaurants / Q000706:statistics & numerical data; D017747:Seafood / Q000032:analysis* / Q000706:statistics & numerical data; D012754:Sharks; D014481:United States; D014874:Water Pollutants, Chemical / Q000032:analysis*
D008767:Methylmercury Compounds; D014874:Water Pollutants, Chemical; C004925:methylmercuric chloride
Food; Mercury; Public health; Shark fin soup