title: Analysis of mercury and methylmercury concentrations, and selenium:mercury molar ratios for a toxicological assessment of sperm whales (Physeter macrocephalus) in the most recent stranding event along the Adriatic coast (Southern Italy, Mediterranean Sea).
abstract: Mass stranding of sperm whales (Physeter macrocephalus) is a rare event in the Mediterranean Sea. In September 2014, a pod of seven sperm whales became stranded along the Adriatic coast of Southern Italy. This is the seventh occurrence of this type since 1555 in this sea basin. Total concentrations of mercury (T-Hg), methylmercury (MeHg) and selenium (Se) were measured from brain, muscle, liver and kidney of three female sperm whales, which died in this event. Analyses showed considerable, age-dependent variations in Hg and Se concentrations in the different organs. The contamination levels of T-Hg in the liver (up to 200 mg kg(-1)) and brain (up to 21 mg kg(-1)) samples were markedly higher than those in the kidney and muscle samples. The liver and brain also showed the highest Se levels. Se:Hg molar ratios ⩾1 were observed in all the organs of the three sperm whales, suggesting that Se could protect the animals from Hg toxicity. The risk of Hg-associated neurotoxicity was assessed by comparing our values to thresholds set for neurotoxicity in mammals, and the role of Se in the detoxification process of T-Hg/MeHg is discussed herein.
authors.affiliation: Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle D'Aosta, via Bologna 148, 10154 Torino, Italy. Electronic address: stefania.squadrone@izsto.it.
authors.forename: S
authors.initials: S
authors.lastname: Squadrone
authors.affiliation: Istituto Zooprofilattico Sperimentale della Puglia e della Basilicata, via Manfredonia 20, 71121 Foggia, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Chiaravalle
authors.affiliation: Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle D'Aosta, via Bologna 148, 10154 Torino, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Gavinelli
authors.affiliation: Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle D'Aosta, via Bologna 148, 10154 Torino, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Monaco
authors.affiliation: Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle D'Aosta, via Bologna 148, 10154 Torino, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Rizzi
authors.affiliation: Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle D'Aosta, via Bologna 148, 10154 Torino, Italy.
authors.forename: M C
authors.initials: MC
authors.lastname: Abete
mesh_terms: D000818:Animals; D054750:Ecotoxicology; D005260:Female; D006801:Humans; D007668:Kidney / Q000187:drug effects / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008522:Mediterranean Sea; D008628:Mercury / Q000378:metabolism* / Q000633:toxicity*; D008767:Methylmercury Compounds / Q000378:metabolism* / Q000633:toxicity*; D009132:Muscles / Q000187:drug effects / Q000378:metabolism; D012643:Selenium / Q000378:metabolism*; D050661:Sperm Whale / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000378:metabolism / Q000633:toxicity
chemical_list: D008767:Methylmercury Compounds; D014874:Water Pollutants, Chemical; D008628:Mercury; D012643:Selenium
keywords: Contaminants; Neurotoxicity; Sperm whales; Stranding