title: Recent contamination by persistent organochlorines in Baikal seal (Phoca sibirica) from Lake Baikal, Russia.
abstract: Blubber samples of Baikal seals pups (Phoca sibirica) collected in 2001 and 2002 were analyzed for persistent organochlorines (OCs) such as PCBs (polychlorinated biphenyls), DDTs (dichlorodiphenyltrichloroethane and its metabolites), HCHs (hexachlorocyclohexane isomers), CHLs (chlordane related compounds), TCPMe [tris(4-chlorophenyl)methane] and TCPMOH [tris(4-chlorophenyl)methanol]. The distribution pattern of OCs was in the following order: DDTs>PCBs>CHLs>HCHs>TCPMOH>TCPMe. Organochlorine concentrations and composition patterns in eight pup blubber samples (2002) analyzed in the present study were compared with the corresponding levels in juvenile Baikal seals from 1992 survey, and it was found that residue levels of OC compounds have declined during the 10 year period. In particular, concentrations of PCBs, HCHs and CHLs in seals collected in 2002 were approximately two times lower, while DDTs levels were three times lower than the corresponding levels in 1992. Furthermore, higher ratios of beta-HCH/HCHs and p,p(')-DDE/DDTs were found in 2002 samples. While comparing the OC levels with those in other seal pups it appeared that all the OC concentrations were lower than the levels in seals from coastal California known as one of the most polluted areas. PCB and DDT concentrations in the present specimens were higher than that in Arctic seal pups. The proportions of tri-, tetra-, penta- and hexachlorobiphenyls in pups captured in 2002 were higher than those in 1992. TEQ concentrations of non- and mono-ortho coplanar PCBs in Baikal seals collected in 2002 were higher than those in seals collected from some locations in the world, where human and industrial activities are extensive, suggesting potential for toxic implications of coplanar PCBs in Baikal seals.
authors.affiliation: Baikal Institute of Nature Management, Sakhyanova st., 6 Ulan-Ude, Buryatia 670047, Russia.
authors.forename: Oyuna
authors.initials: O
authors.lastname: Tsydenova
authors.forename: Tu Binh
authors.initials: TB
authors.lastname: Minh
authors.forename: Natsuko
authors.initials: N
authors.lastname: Kajiwara
authors.forename: Valeriy
authors.initials: V
authors.lastname: Batoev
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Tanabe
mesh_terms: D000273:Adipose Tissue / Q000737:chemistry*; D000818:Animals; D002849:Chromatography, Gas; D002850:Chromatography, Gel; D004784:Environmental Monitoring; D005618:Fresh Water; D006843:Hydrocarbons, Chlorinated / Q000032:analysis*; D012426:Russia; D046048:Seals, Earless / Q000378:metabolism*; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D006843:Hydrocarbons, Chlorinated; D014874:Water Pollutants, Chemical