Mercury exposure and elimination rates in captive bottlenose dolphins.
Mercury concentrations in fish, faeces and exhaled air were investigated in order to evaluate total mercury exposure through the gut in captive bottlenose dolphin and excretion via intestine and pulmonary routes. Results showed that faeces account for elimination of 34-48% of dietary mercury; while only 0.9-1.2% of alimentary mercury is eliminated through exhaled air. The remaining 51.2-65.3% of ingested mercury, ranging approximately between 266 and 339 microg per day, is retained within the organism. The complexation of mercury with selenium, forming insoluble tiemannite granules, is discussed as an important mechanism, complementary to excretion, by which odontocetes are able to cope with elevated alimentary exposure to mercury.
Nigro
M
M
Dipartimento di Morfologia Umana e Biologia Applicata, sez. Biologia e Genetica, Università di Pisa, Via Volta, 4 I-56126 Pisa, Italy. nigro@biomed.unipi.it
Campana
A
A
Lanzillotta
E
E
Ferrara
R
R
D000818:Animals; D004064:Digestive System; D004289:Dolphins; D004781:Environmental Exposure; D005243:Feces / Q000737:chemistry; D005260:Female; D005399:Fishes; D020387:Food Chain; D005506:Food Contamination; D008297:Male; D008628:Mercury / Q000032:analysis / Q000493:pharmacokinetics*; D012119:Respiration; D014018:Tissue Distribution; D014873:Water Pollutants / Q000032:analysis / Q000493:pharmacokinetics*
D014873:Water Pollutants; D008628:Mercury