title: Contamination levels of mercury and cadmium in melon-headed whales (Peponocephala electra) from a mass stranding on the Japanese coast.
abstract: Total mercury (T-Hg), methyl mercury (M-Hg), cadmium (Cd), selenium (Se), zinc (Zn) and copper (Cu) concentrations in the organs of melon-headed whales from a mass stranding on the Japanese coast were analyzed. The mean concentration of T-Hg in the liver (126+/-97 microg/wet g, n=13) was markedly higher than those in kidney (6.34+/-2.36 microg/wet g, n=12) and muscle (4.90+/-2.33 microg/wet g, n=15). In contrast, the mean concentration of M-Hg in the liver (9.08+/-2.24 microg/wet g) was similar to those in the kidney (3.47+/-0.91 microg/wet g) and muscle (3.78+/-1.53 microg/wet g). The mean percentage of M-Hg in the T-Hg found in the liver (13.1+/-10.3) was significantly lower than those in the kidney (58.3+/-15.0) and muscle (78.9+/-8.4). The molar ratio of T-Hg to Se in the liver was effectively 1.0, but those in the kidney and muscle were markedly lower. Conversely, the mean concentration of Cd was markedly higher in the kidney (24.4+/-7.4 microg/wet g) than in the liver (7.24+/-2.08 microg/wet g) and muscle (less than 0.05 microg/wet g). These results suggest that the formation of Hg-Se compounds mainly occurs in the liver after the demethylation of M-Hg, and Cd preferentially accumulates in the kidney of melon-headed whales.
authors.affiliation: Faculty of Pharmaceutical Sciences, Health Sciences University of Hokkaido, 1757 Ishikari-Tobetsu, Hokkaido 061-0293, Japan. endotty@hoku-iryo-u.ac.jp
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Endo
authors.forename: Yohsuke
authors.initials: Y
authors.lastname: Hisamichi
authors.forename: Osamu
authors.initials: O
authors.lastname: Kimura
authors.forename: Koichi
authors.initials: K
authors.lastname: Haraguchi
authors.forename: C Scott
authors.initials: CS
authors.lastname: Baker
mesh_terms: D000818:Animals; D002104:Cadmium / Q000032:analysis* / Q000493:pharmacokinetics / Q000633:toxicity; D002947:Cities; D003300:Copper / Q000032:analysis / Q000493:pharmacokinetics / Q000633:toxicity; D004289:Dolphins; D004784:Environmental Monitoring; D005506:Food Contamination / Q000032:analysis*; D005843:Geography; D007564:Japan; D007668:Kidney / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008628:Mercury / Q000032:analysis* / Q000493:pharmacokinetics / Q000633:toxicity; D009132:Muscles / Q000378:metabolism; D012623:Seawater; D012643:Selenium / Q000032:analysis / Q000493:pharmacokinetics / Q000633:toxicity; D014018:Tissue Distribution; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000493:pharmacokinetics / Q000633:toxicity; D015032:Zinc / Q000032:analysis / Q000493:pharmacokinetics / Q000633:toxicity
chemical_list: D014874:Water Pollutants, Chemical; D002104:Cadmium; D003300:Copper; D008628:Mercury; D012643:Selenium; D015032:Zinc