PCDDs, PCDFs, and coplanar PCBs in albatross from the North Pacific and Southern Oceans: levels, patterns, and toxicological implications.
ABSTRACT Concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and coplanar polychlorinated biphenyls (coplanar PCBs) were determined in five albatross species collected from the North Pacific and Southern Oceans to assess the north-south differences in residue levels, accumulation patterns, and toxic potential. Black-footed and Laysan albatrosses from the North Pacific Ocean contained higher levels of PCDD/Fs and coplanar PCBs than albatrosses from the Southern Ocean, indicating that emission sources of these contaminants were predominant in the northern hemisphere. Residue levels in albatrosses from the remote North Pacific Ocean far from the point source of pollution were comparable to or higher than those in terrestrial and coastal birds from contaminated areas in developed nations, suggesting the specific exposure and accumulation of PCDD/Fs and coplanar PCBs in albatross. The long life span and ingestion of plastic resin pellets by albatrosses could be the plausible explanations for the elevated accumulation of persistent and lipophilic contaminants including PCDD/Fs and coplanar PCBs in these birds. Relative proportions of PCDFs and coplanar PCBs in albatross were higher than those observed in birds inhabiting terrestrial and coastal areas, suggesting that these toxic chemicals may have higher transportability by air and water than PCDDs. Congener patterns of PCDD/Fs in albatross showed less variability as compared to those in terrestrial species, indicating that contamination patterns of PCDD/Fs were similar within the open ocean environment. Contributions of PCDD/Fs to total TEQs in albatrosses from the open ocean were generally lower than those in terrestrial birds, suggesting different toxic potency of PCDD/Fs and coplanar PCBs on animals inhabiting open ocean and terrestrial environment. Whereas albatrosses from southern oceans retained lower TEQ concentrations, possible adverse effects of PCDD/Fs and coplanar PCBs to black-footed and Laysan albatrosses of the North Pacific Ocean may be suspected from TEQ levels.
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ABSTRACT: Carbon and nitrogen stable isotopes in albatrosses and petrels collected off southern Brazil were compared with concentrations of organochlorine contaminants (OCs). δ(13)C and δ(15)N values, as well as OCs concentrations, exhibited a high degree of variability among individuals and overlap among species. δ(13)C values reflected latitudinal differences among species, with lower values found in Wandering and Tristan Albatrosses and higher values found in Black-browed and Atlantic Yellow-nosed Albatrosses and White-chinned Petrels. Some relationships were found between OCs and stable isotopes, but in general a partial 'uncoupling' was observed between OCs concentrations and stable isotopes ratios (especially for δ(15)N). δ(13)C and δ(15)N values in Procellariiformes tissues during the non-breeding season appear to be a better indicator of foraging habitats than of trophic relationships, which may partially explain the high degree of variability between concentrations of OCs and stable isotopes ratios in birds with a diversified diet and wide foraging range.Marine pollution bulletin 04/2014; · 2.63 Impact Factor
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ABSTRACT: This study investigates kinetic and production parameters of a glucose-utilizing bacterial strain, C. eutrophus B-10646, and its ability to synthesize PHA terpolymers. Optimization of a number of parameters of bacterial culture (cell concentration in the inoculum, physiological activity of the inoculum, determined by the initial intracellular polymer content, and glucose concentration in the culture medium during cultivation) provided cell concentrations and PHA yields reaching 110 g/L and 80%, respectively, under two-stage batch culture conditions. Addition of precursor substrates (valerate, hexanoate, propionate, γ-butyrolactone) to the culture medium enabled synthesis of PHA terpolymers, P(3HB/3HV/4HB) and P(3HB/3HV/3HHx), with different composition and different molar fractions of 3HB, 3HV, 4HB, and 3HHx. Different types of PHA terpolymers synthesized by C. eutrophus B-10646 were used to prepare films, whose physicochemical and physical-mechanical properties were investigated. The properties of PHA terpolymers were significantly different from those of the P3HB homopolymer: they had much lower degrees of crystallinity and lower melting points and thermal decomposition temperatures, with the difference between these temperatures remaining practically unchanged. Films prepared from all PHA terpolymers had higher mechanical strength and elasticity than P3HB films. In spite of dissimilar surface structures, all films prepared from PHA terpolymers facilitated attachment and proliferation of mouse fibroblast NIH 3T3 cells more effectively than polystyrene and the highly crystalline P3HB.PLoS ONE 01/2014; 9(2):e87551. · 3.53 Impact Factor
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ABSTRACT: Relationships between persistent organic pollutant (POP) levels and age in wildlife biomonitoring are often interpreted as changes in contaminant burden as organisms age. However cross-sectional body burden-age trends (CBATs) obtained from biomonitoring studies, which sample individuals of different age at the same time, should not be confused with longitudinal body burden-age trends (LBATs) obtained by sampling the same individuals repeatedly through time. To clarify how CBATs and LBATs for wildlife species deviate from each other, and describe any impact of lifespan and sex, we used mechanistic bioaccumulation models to estimate historic longitudinal exposures of polar cod, ringed seals, beluga whales, and bowhead whales to polychlorinated biphenyl congener 153. CBATs were then produced by "sampling" resultant LBATs of successive birth cohorts at specific timepoints. As found previously for humans, the year of sampling relative to the year of peak environmental contamination was a critical parameter in determining male CBAT shapes. However, a similar cohort effect was not apparent for reproductive females because efficient POP loss through lactation prevented their lipids from retaining a "memory" of past exposure levels. Thus, lactation loss was not only responsible for the large differences between the CBATs of males and females of the same species, but also the lack of female CBAT variability through time. CBAT shapes varied little between species by lifespan, as long as equivalent age scales were used. However, lifespan relative to the timescale of environmental contaminant level changes did determine the extent to which CBATs resembled LBATs for males. We suggest that accounting for birth cohort and sex effects is essential when interpreting age trends in POP biomonitoring studies of long-lived species. Environ Toxicol Chem © 2014 SETAC.Environmental Toxicology and Chemistry 03/2014; · 2.62 Impact Factor