Seasonal Variation of Persistent Organochlorine Accumulation in Birds from Lake Baikal, Russia, and the Role of the South Asian Region as a Source of Pollution for Wintering Migrants

Abstract

Concentrations of persistent organochlorines (OCs) such as polychlorinated biphenyls (PCBs), DDT and its metabolites (DDTs), hexachlorocyclohexane isomers (HCHs), and chlordane compounds (CHLs) were determined in whole body soft tissue homogenates and in muscles of resident and migratory birds collected from Lake Baikal, Russia. The residue pattern in both resident and migratory birds was in the following order: PCBs > DDTs > HCHs > CHLs. OC concentrations in migratory birds varied, depending on the feeding habit. The maximum levels of OCs were found in piscivores, followed by insectivores, omnivores, and herbivores. OC residue levels in Lake Baikal birds were lower than those in the Great Lakes region as well as in other lakes in Europe and Japan. Concentrations of HCHs and DDTs in most of the migratory birds collected in the spring were higher than for those collected in the autumn, indicating a notable accumulation in wintering grounds. Compilation and analysis of the available data in fish and birds from Asia suggested that the tropical and subtropical regions in south Asian countries may be a source of pollution for the wintering accumulation of migratory birds from Lake Baikal. Relatively higher compositions of alpha- and gamma-HCH in total HCHs, p,p'-DDT in total DOTs were observed in some migratory species, indicating recent exposure to HCHs and DDTs in Lake Baikal or wintering areas. PCB isomer patterns were different between residents and migrants, with the predominance of lower chlorinated congeners in migratory species, suggesting recent PCB accumulation in stopover sites during wintering. TEQ concentrations of toxic non- and mono-ortho coplanar PCBs in common terns from Lake Baikal were comparable to those reported in some species from Japan, the United States, and Europe. Relative contributions of non-ortho coplanar congeners to toxic equivalents (TEQs) were predominant, in which CB-126 accounted for the highest toxicity contribution. Estimated TEQ concentrations in the common tern from Lake Baikal exceeded the levels associated with enzyme induction in bald eagles. To our knowledge, this is the first comprehensive study showing the seasonal variations of OC accumulation in the birds from Lake Baikal.

PCBs and DDTs in light-vented bulbuls from Guangdong Province, South China: Levels, geographical pattern and risk assessment

“…Among mono-ortho-PCB congeners (PCB 105,118,123,156,157 and 169), PCB 105 was the major contributor to TEQ concentrations (53.8%), followed by PCB 156 and PCB 118. This pattern was similar to other studies on predatory birds from northern China (Chen et al, 2009b) and aquatic birds from Russia and Switzerland (Zimmermann et al, 1997;Kunisue et al, 2002). The levels of TEQ in light-vented bulbul ranged from 0.25 to 912 pg/g lw.…”

Geographic and Seasonal Variation in Mercury Exposure of the Declining Rusty Blackbird

“…In addition, they are long-distance migrants that visit many countries with poor pollution control practices, increasing their risk of contaminant exposure (Kunisue et al 2002). Areas of Central and South America are of particular concern because mercury contamination is significantly increasing due to artisanal small-scale gold mining (UNEP 2013).…”

Dioxins and organohalogen contaminants in the Asia-Pacific region

“…In addition, release from electrical equipment, leakages of hydraulic fluids from shipping vessels and old transformers and capacitors could be potential reason for elevated PCBs contamination encountered in mussels from coastal waters of these countries (Ramu et al 2007). Using resident and migratory birds as bioindicators, high concentrations of organochlorine insecticides and PCBs were found in birds collected at stopover/wintering areas of tropical Asian developing countries and Russia/Japan, respectively (Kunisue et al 2002aMinh et al 2002). To substantiate our findings with further evidence on pollution sources of organochlorines, we collected human breast milk from Asian countries and determined residue levels of contaminants ( Table 1).…”

“…In case of dioxins, it is reported that 1-3 monthold infants absorb above 90% of most dioxin congeners present in their mothers milk (Dahl et al 1995;McLachlan 1993), hence they may be exposed to relatively high levels of POPs during this period. To understand the magnitude of exposure to POPs by infants, we estimated daily intake (DI) from the levels of these contaminants in human breast milk observed in Asian countries, based on the assumption that an infant ingests 700 ml milk per day and the weight of an infant is 5 kg (Kunisue et al 2002a(Kunisue et al , b, 2004aMinh et al 2004;Sudaryanto et al 2005aSudaryanto et al , b, 2006 and compared the values with the guideline standards proposed by WHO and Health Canada (Van Leeuwen et al 2000;Oostdam et al 1999).…”