Springer Science and Business Media LLC

Interspecies differences in “B” esterases were evaluated in seven species of wild birds in order to investigate their different susceptibilities to organophosphorus (OP) insecticides. The relationship between “B” esterases and body size and the influence of feeding habits in the evolution of esterase activities were explored. An in vitro inhibition test was carried out with paraoxon and azinphos methyl oxon in order to investigate the role of equilibrium binding parameters (acetylcholinesterase/organophosphorus compounds affinity) in determining susceptibility of the different species to parathion and azinphos methyl. Esterase activities were different in all species. The smallest bird studied (the sparrow) had the highest brain acetylcholinesterase (AChE) and plasma carboxylesterase (CbE) activities. The largest bird (the cormorant) had the lowest level of both activities. For microsomal CbE, the coot had the highest activity. An inverse correlation was found between brain AChE and plasma CbE activity in relation to body size. Omnivorous species showed the highest brain AChE and plasma CbE activities which were low in species with a specialised diet. The in vitro inhibition test demonstrated the active involvement of equilibrium binding parameters in determining different susceptibilities to these contaminants in birds.

Biologic sample collection in wild cetacean populations is challenging. Most information on toxicant levels is obtained from blubber biopsy samples; however, sample collection is invasive and strictly regulated under permit, thus limiting sample numbers. Methods are needed to monitor toxicant levels that increase temporal and repeat sampling of individuals for population health and recovery models. The objective of this study was to optimize measuring trace levels (parts per billion) of persistent organic pollutants (POPs), namely polychlorinated-biphenyls (PCBs), polybrominated-diphenyl-ethers (PBDEs), dichlorodiphenyltrichloroethanes (DDTs), and hexachlorocyclobenzene, in killer whale scat (fecal) samples. Archival scat samples, initially collected, lyophilized, and extracted with 70 % ethanol for hormone analyses, were used to analyze POP concentrations. The residual pellet was extracted and analyzed using gas chromatography coupled with mass spectrometry. Method detection limits ranged from 11 to 125 ng/g dry weight. The described method is suitable for p,p′-DDE, PCBs-138, 153, 180, and 187, and PBDEs-47 and 100; other POPs were below the limit of detection. We applied this method to 126 scat samples collected from Southern Resident killer whales. Scat samples from 22 adult whales also had known POP concentrations in blubber and demonstrated significant correlations (p < 0.01) between matrices across target analytes. Overall, the scat toxicant measures matched previously reported patterns from blubber samples of decreased levels in reproductive-age females and a decreased p,p′-DDE/∑PCB ratio in J-pod. Measuring toxicants in scat samples provides an unprecedented opportunity to noninvasively evaluate contaminant levels in wild cetacean populations; these data have the prospect to provide meaningful information for vital management decisions.

English sole (Parophyrs vetulus) in Puget Sound, Washington, USA are at risk of hepatocarcinogenesis specifically in areas adjacent to polluting industrial effluents. A question concerning population and ecosystem survival is whether any of the effects of etiopathologic change are reversible. This has been approached by looking for evidence of tumor accelerating effects in an exposed population. Cellular parameters were determined by flow cytometry for hepatocytes of English sole. Cells containing hyperdiploid DNA not present in fish from reference waters, Port Madison, were found in all non-tumor-bearing and tumor bearing fish taken from a polluted site, Eagle Harbor, where incidence of hepatic neoplasia approaches 30%. Induction of altered DNA content in the exposed general hepatocyte population suggests environmental induction rather than an association with lesionsper se. In contrast, glutathione levels in hepatocytes (0.8–3.2 nmol/mg protein), were little influenced by the exposure site, consistent with the apparent lack of protection against chemically induced carcinogenesis in English sole. Association of altered DNA content with exposure site is significant for its potential contribution to biological acceleration and evidence of tumor promotion found at the tissue and organismic levels. The results support the notion that hepatocarcinogenesis in English sole in Eagle Harbor has a multi-year exposure etiology, in which potentially reversible accelerating influences have a role, and that glutathione conjugation is an inadequate mode of detoxification for these fish.

Polycyclic musk fragrances are common additives to many consumer products. As a result of their widespread use and slow degradation rates, they are widely found in aquatic environments. This study reports on the lethal and sublethal toxicity of the polycyclic musks AHTN (Tonalide®) and HHCB (Galaxolide®) to glochidial (larval) and juvenile life stages of the freshwater mussel Lampsilis cardium (Rafinesque, 1820). In glochidia, 24-h median lethal concentrations (LC50s) ranged from 454 to 850 μg AHTN/L and from 1000 to >1750 μg HHCB/L (water solubility). Results for 48-h tests were similar to the 24-h tests. In 96-h tests with juveniles, we did not observe a dose-response relation between mortality and either musk. However, the growth rate was reduced by musk exposure. The median effective concentrations (EC50s, based on growth) were highly variable and ranged from 108 to 1034 μg AHTN/L and 153 to 831 μg HHCB/L. While all adverse effects occurred at concentrations that are much greater than those reported in natural waters (low μg/L to ng/L), these results indicate the potential for adverse effects on these long-lived organisms from exposure to synthetic musk fragrances.

Many studies demonstrated the presence of diverse environmental contaminants in the Douro River estuary, such as natural and synthetic estrogens, pharmaceuticals, industrial compounds and pesticides. This estuary is located between two densely populated cities and is highly impacted due to anthropogenic activities, such as industry and agriculture. Although the presence of mycotoxins and phytoestrogens, such as lignans and coumestrans, in the aquatic environment is reported by some authors, their occurrence in Portuguese waters was not investigated yet. To evaluate the presence of phytoestrogens, phytosterols and mycotoxins in Douro River estuary, water samples were collected seasonally at nine sampling points, preconcentrated by solid phase extraction and analysed by gas chromatography mass spectrometry. Local flora was collected on the riverside, in the same sampling points, for identification and evaluation of the possible relation to the presence of phytoestrogens and/or phytosterols in the estuarine water. Results showed the ubiquitous presence of mycotoxins, namely deoxynivalenol up to 373.5 ng L−1. Both phytoestrogens and phytosterols showed a possible seasonal fluctuation, which is in accordance to the life cycle of the local flora and agricultural practices. Physicochemical parameters were also determined for water quality evaluation. This study revealed for the first time the presence of mycotoxins and lignans in estuarine waters from Portugal, and highlights the need to consider natural contaminants in future monitoring programs.

Wildlife contamination studies found high levels of DDT and associated metabolites in bird eggs from Canadian orchard sites during the early 1990s. The present study investigated local dietary uptake of DDT and geographic variability in tissue concentrations in the same orchards. A soil–earthworm–robin food chain was chosen for study, as early surveys showed that robins contained the highest levels of DDT of several avian species and because published research indicated that earthworms were a probable dietary exposure route. Organochlorine pesticides and PCBs were measured in soil, earthworm, robin egg, and robin nestling samples collected from fruit orchards and reference sites. High average DDE (soil: 5.2 mg/kg; earthworm: 52 mg/kg; robin egg: 484 mg/kg dry weight) and DDT (soil: 9.2 mg/kg; earthworm: 21 mg/kg; robin egg: 73 mg/kg dry weight) concentrations in Okanagan (British Columbia) samples confirmed that previously recorded contamination was common in the region. Concentrations detected in Simcoe, Ontario, orchards were not as high but were still significantly elevated relative to levels in soils and robins from reference areas. Significant positive linear regressions between soil and earthworm concentrations and consistent trends in food chain accumulation suggested that robins were acquiring DDT and metabolite (DDTr) burdens locally. Low concentrations of DDT and DDTr in robin eggs collected from nests in nearby nonorchard and post-DDT orchard habitats suggested that the local sources were in orchards. Persistence of DDT in orchard food chains is likely due to a combination of retarded degradation rates for DDT in soil and its extensive use historically. DDT concentrations in some robin eggs and earthworms were at levels comparable to those observed in field studies where mortality or reproductive effects occurred.