Fluctuating concentrations of organochlorine pollutants during a breeding season in two antarctic seabirds: Adelie Penguin and Southern Fulmar

During the reproductive cycle significant fluctuations of concentrations of organochlorine pollutants were detected in blood and uropygial oil from Adelie penguins (Pygoscelis adeliae) and southern fulmars (Fulmarus glacialoides) from Hop Island, Antarctica. In the Adelie penguin, concentrations of polychlorinated biphenyls (PCBs) and dieldrin were significantly higher at the moment of egg laying, while hexachlorobenzene (HCB) and 2,2-bis(p-chlorophenyl)-1,1-dichloroethylene (p,p'-DDE) concentrations peaked at the creche stage. Subcutaneous fat is the main pool for HCB and p,p'-DDE, while PCBs and dieldrin are also stored n the pectoral muscle. It is hypothesized that the observed differences in seasonal fluctuations in organochlorine levels are related to utilization of different storage pools by the Adelie penguins at different moments in the breeding season. In the southern fulmar the fluctuations in concentrations of HCB and p,p'-DDE can be related to changes in body mass. However, concentrations of PCBs and dieldin did not vary significantly during the season. It seems that the two groups of compounds are governed more or less independently in the southern fulmar as well. Age-dependent accumulation of most organochlorines studied reached a steady state before the age at which both species start to breed. This allows monitoring of individual birds to analyze changes in concentrations of organochlorine pollutants in the ecosystem, without having to correct for age differences. Differences in levels of organochlorine pollutants between the Adelie penguin and southern fulmar were probably the result of differences in feeding ecology

Modelling and monitoring organochlorine and heavy metal accumulation in soils, earthworms, and shrews in Rhine-Delta floodplains

In the Rhine-delta, accumulation of microcontaminants in floodplain foodwebs has received little attention in comparison with aquatic communities. To investigate organochlorine and metal concentrations in a terrestrial foodchain, samples of soil, earthworms (Lumbricus rubellus), and shrew (Crocidura russula, Sorex araneus) livers and kidneys were taken from two moderately to heavily polluted floodplains. Chlorobiphenyl residues in earthworm fat were 0.10 to 3.5 times the concentrations in soil organic matter, whereas ratios for other organochlorines varied between 0.87 and 8.8. These ratios are one order of magnitude lower than expected from laboratory experiments with earthworms, and laboratory and field studies on aquatic invertebrates. Bioconcentration ratios for heavy metals are in accordance with literature values for other locations, confirming the high potential for cadmium accumulation in Lumbricidae. Concentrations of organochlorines in shrew liver lipids were 1.0 to 13 times the residues in earthworm fat. These values are higher than lipid-corrected biomagnification ratios for laboratory rodents, but equal to those measured for benthivorous birds in the Rhine- delta. On a dry weight basis, kidney-earthworm ratios for cadmium were about one order of magnitude lower than previously reported values for insectivores. Soil concentrations of many compounds in both floodplains did not meet Dutch quality standards. Yet, hexachlorobenzene, chlorobiphenyl 153 (PCB153), γ-hexachlorocyclohexane, ΣDDT, and dieldrin residues in earthworms and shrews did not exceed diet levels expected to be safe for endothermic species. An exception was noted for cadmium in worms and shrew kidneys. Heavy metal pollution in soil was close to levels that are critical to earthworms in laboratory studies. Cadmium concentrations in shrew kidneys were below levels suggested to be safe for Sorex araneus, but above those that were critical to the rat

Fluctuating concentrations of organochlorine pollutants during a breeding season in two antarctic seabirds: Adelie Penguin and Southern Fulmar

During the reproductive cycle significant fluctuations of concentrations of organochlorine pollutants were detected in blood and uropygial oil from Adelie penguins (Pygoscelis adeliae) and southern fulmars (Fulmarus glacialoides) from Hop Island, Antarctica. In the Adelie penguin, concentrations of polychlorinated biphenyls (PCBs) and dieldrin were significantly higher at the moment of egg laying, while hexachlorobenzene (HCB) and 2,2-bis(p-chlorophenyl)-1,1-dichloroethylene (p,p'-DDE) concentrations peaked at the creche stage. Subcutaneous fat is the main pool for HCB and p,p'-DDE, while PCBs and dieldrin are also stored n the pectoral muscle. It is hypothesized that the observed differences in seasonal fluctuations in organochlorine levels are related to utilization of different storage pools by the Adelie penguins at different moments in the breeding season. In the southern fulmar the fluctuations in concentrations of HCB and p,p'-DDE can be related to changes in body mass. However, concentrations of PCBs and dieldin did not vary significantly during the season. It seems that the two groups of compounds are governed more or less independently in the southern fulmar as well. Age-dependent accumulation of most organochlorines studied reached a steady state before the age at which both species start to breed. This allows monitoring of individual birds to analyze changes in concentrations of organochlorine pollutants in the ecosystem, without having to correct for age differences. Differences in levels of organochlorine pollutants between the Adelie penguin and southern fulmar were probably the result of differences in feeding ecology

Polychlorinated biphenyls pattern analysis: potential nondestructive biomarker in vertebrates for exposure to cytochrome P450-inducing organochlorines

Biomarkers are valuable instruments to assess the risks from exposure of organisms to organochlorines. In general, however, these biomarkers are either destructive to the animal of interest or extremely difficult to obtain otherwise. In this paper, we present a nondestructive biomarker for exposure to cytochrome P450-inducing organochlorines. This marker is based on a pattern analysis of metabolizable and nonmetabolizable polychlorinated biphenyl (PCB) congeners, which occur in several kinds of tissues (and even blood) that can be obtained without serious effects on the organism involved. The fraction of metabolizable PCB congeners is negatively correlated with exposure to PCBs, which are known to induce specific P450 isoenzymes. This relation can be modeled by a logistic curve, which can be used to define critical levels of exposure. In addition, this method creates an opportunity to analyze biomarker responses in archived tissues stored at standard freezing temperatures (-20°C), at which responses to established biomarkers deteriorate. Furthermore, this method facilitates attribution of the enzyme induction to certain classes of compounds

Polychlorinated biphenyls pattern analysis: potential nondestructive biomarker in vertebrates for exposure to cytochrome P450-inducing organochlorines

Biomarkers are valuable instruments to assess the risks from exposure of organisms to organochlorines. In general, however, these biomarkers are either destructive to the animal of interest or extremely difficult to obtain otherwise. In this paper, we present a nondestructive biomarker for exposure to cytochrome P450-inducing organochlorines. This marker is based on a pattern analysis of metabolizable and nonmetabolizable polychlorinated biphenyl (PCB) congeners, which occur in several kinds of tissues (and even blood) that can be obtained without serious effects on the organism involved. The fraction of metabolizable PCB congeners is negatively correlated with exposure to PCBs, which are known to induce specific P450 isoenzymes. This relation can be modeled by a logistic curve, which can be used to define critical levels of exposure. In addition, this method creates an opportunity to analyze biomarker responses in archived tissues stored at standard freezing temperatures (-20°C), at which responses to established biomarkers deteriorate. Furthermore, this method facilitates attribution of the enzyme induction to certain classes of compounds