Total mercury, methyl mercury, and selenium levels in the red meat of small cetaceans sold for human consumption in Japan.
We surveyed the total mercury (T-Hg) and methyl mercury (M-Hg) levels in red meat products (n = 160) from small cetacean species sold for human consumption in markets throughout Japan from 2000 to 2003. Genetic identification showed that the red meat products originated from nine species: false killer whale, bottlenose dolphin, short-finned pilot whale, striped dolphin, rough-toothed dolphin, Risso's dolphin, pantropical spotted dolphin, Baird's beaked whale, and Dall's porpoise. T-Hg and M-Hg concentrations in all red meat products exceeded the provisional permitted levels of T-Hg (0.4 microg/wet g) and M-Hg (0.3 microg/ wet g) in fish and shellfish set by the Japanese government, respectively. The average M-Hg level in the most contaminated species (false killer whale) was 11.5 microg/wet g, and that in the least contaminated species (Dall's porpoise) was about 1.0 microg/wet g, exceeding or equaling the Codex guideline of M-Hg in predatory fishes (1.0 microg/wet g). Contamination levels of T-Hg and M-Hg differed considerably among samples of the nine species and among individuals of a particular species. The highest M-Hg was about 26 microg/ wet g in a sample from a striped dolphin, 87-times higher than the permitted level. The consumption of only 4 g of this product would exceed the provisional tolerable weekly intake of M-Hg for someone of 60 kg body weight (1.6 microg/kg-bw/ week). Although a high correlation between T-Hg and selenium (Se) was observed in these products, the molar ratio of T-Hg to Se was substantially higher than 1. The consumption of red meat from small cetaceans, therefore, could pose a health problem for not only pregnant women but also for the general population.
Endo
Tetsuya
T
Faculty of Pharmaceutical Sciences, Health Sciences University of Hokkaido, 1757 Ishikari-Tobetsu, Hokkaido 061-0293, Japan. endotty@hoku-iryo-u.ac.jp
Haraguchi
Koichi
K
Hotta
Yohei
Y
Hisamichi
Yohsuke
Y
Lavery
Shane
S
Dalebout
Merel L
ML
Baker
C Scott
CS
D000818:Animals; D002591:Cetacea; D004034:Diet Surveys; D005506:Food Contamination / Q000032:analysis*; D006801:Humans; D007564:Japan; D008628:Mercury / Q000032:analysis*; D008767:Methylmercury Compounds / Q000032:analysis*; D017747:Seafood / Q000032:analysis*; D012643:Selenium / Q000032:analysis*
D008767:Methylmercury Compounds; D008628:Mercury; D012643:Selenium