From environmental bioavailability of metal(loid)s to their ecogenotoxicological effects in land snails

Environmental Science and Pollution Research - To date, no study has linked the environmental and the ecogenotoxicological bioavailability of contaminants to land snails. Yet, understanding the...     

Polyethylene microplastic toxicity to the terrestrial snail Cantareus aspersus: size matters

Environmental Science and Pollution Research - Plastic has become the most widespread human-made material and small fragments (< 5mm, so called microplastics, MPs) accumulate in all the...     

Misunderstanding the “Nature” of Co-Management: A Geography of Regulatory Science and Indigenous Knowledges (IK)

Governments, NGOs, and natural scientists have increased research and policy-making collaborations with Indigenous peoples for governing natural resources, including official co-management regimes. However, there is continuing dissatisfaction with such collaborations, and calls for better communication and mutual learning to create more “adaptive” co-management regimes. This, however, requires that both Western and Indigenous knowledge systems be equal participants in the “co-production” of regulatory data. In this article, I examine the power dynamics of one co-management regulatory regime, conducting a multi-sited ethnography of the practices of researching and managing one transnational migratory species, greater white-fronted geese (Anser albifrons frontalis), who nest where Koyukon Athabascans in Alaska, USA, practice subsistence. Analyzing the ethnographic data through the literatures of critical geography, science studies and Indigenous Studies, I describe how the practice of researching for co-management can produce conflict. “Scaling” the data for the co-management regime can marginalize Indigenous understandings of human–environment relations. While Enlightenment-based practices in wildlife biology avoid “anthropomorphism,” Indigenous Studies describes identities that operate through non-modern, deeply imbricated human–nonhuman identities that do not separate “nature” and “society” in making knowledge. Thus, misunderstanding the “nature” of their collaborations causes biologists and managers to measure and research the system in ways that erase how subsistence-based Indigenous groups already “manage” wildlife: by living through their ethical commitments to their fellow beings. At the end of the article, I discuss how managers might learn from these ontological and epistemological differences to better “co-produce” data for co-management.     

Entwicklung von Prüfwertempfehlungen für ausgewählte Schadstoffe zum Schutz des Bodens als Lebensraum für Bodenorganismen

Goal and Scope

In the German Federal Soil Protection and Contaminated Sites Ordinance there are no ecotoxicological trigger values for the protection of soil as a habitat for soil organisms. The objective of this study was to derive preliminary trigger values for the habitat function of soils. This was done by collecting data on the impact of priority pollutants on soil organisms and plants followed by the parallel use of the Factorial Application Method (FAME) and Distribution Based Extrapolation (DIBAEX) and a final verification of the plausibility of the calculated trigger values by means of an ecotoxicological test battery.

Methods

Data on the effects of pollutants on soil organisms and plants were recorded in a specific data base (Soil Value). Subsequently, we derived so-called ‘working trigger values’ using the extrapolation methods FAME (factorial application method) and DIBAEX (distribution based extrapolation). In the second phase of the project, we verified experimentally the plausibility of these values by means of an ecotoxicological test battery. Test substrate was a sandy soil with low sorption capacity and organic carbon content which was mixed with fresh pollutants (e.g. heavy metal salts) and polluted soil material from contaminated sites (aged contamination), respectively. Organisms tested were microorganisms, plants, earthworms, springtails and nematodes.

Results and Conclusions

We calculated working trigger values for 12 pollutants based on 900 datasets compiled in he data base. The laboratory investigations showed the freshly added contaminants to be less strongly adsorbed to the soil than those added by the use of contaminated soil material. Nevertheless, aged contaminations displayed often the same inhibitive effects as the freshly added chemicals. The results achieved in the second phase of the project were also recorded in the Soil-Value database. Based on the new data set, final trigger values were derived for the experimentally tested substances.

Outlook

The procedure described in this contribution exemplarily for copper can be used for the derivation of recommended trigger values for the pathway soil ? soil organisms. Besides copper, preliminary trigger values were derived for zinc, mercury, lead and HCH.     

Bestimmung von Redoxzonen in einem mineralölbelasteten Grundwasserleiter

Goal and Scope

The goal of this study is the investigation and the grafic presentation of the characteristic redox zonation in a mineral oil contaminated aquifer which will be formed in the plume downstream of the contamination source. Methanogenic conditions, sulfate-reduction, Fe(III)-reduction, Mn(IV)-reduction, nitrate-reduction, aerobic conditions. By that indications type and degree of microbial degradation which is the most important part in Natural Attenuation (NA) processes can be obtained easily.

Methods

Changes of the groundwater parameters Eh, O₂, NO ₃ ^? , SO₄ ^2?, Fe²⁺, Mn²⁺, HCO₃ ^?, Ca²⁺ will be measured upstream, downstream and also in the centre of the plume. The results will be presented in a sequence of special diagrams.

Results and Conclusion

When microbial degradation of hydrocarbons takes place, a microbial community will always use that electron acceptor from which it will gain a maximum of energy by the corresponding redox-reactions. This means as long as oxygen is available this will be used. After its depletion nitrate serves as electron acceptor leading via nitrite to the formation of nitrogen or ammonia. Manganese (IV) and Iron (III) species which are rather insoluble are mainly available from the soil-phase, can act as electron acceptor as next, leading to soluble Manganese (II) and Iron (II) compounds in groundwater. Finally before methanogenic conditions occur sulphate will become a suitable electron acceptor leading to the formation of hydrogen sulphide. All these processes of mineralization of the hydrocarbons will lead to the production of CO₂ and as consequence to an increase of HCO₃ ^? in groundwater changing the calcareous/carbonic acid-equilibrium. By that more soluble Ca(HCO₃)₂ is formed from insoluble CaCO₃, so the concentration from Ca²⁺ will also inerease. Thus, by the action of microorganisms, a typical redox-zonation and changes of other parameters will occur.

Recommendations and Perspective

To follow the changes in time and space of some characteristic groundwater parameters is a simple way to estimate the potential of microbial degradation in a contaminated aquifer considering Natural Attenuation (NA)-processes.     

Aerosol particle number concentration measurements in five European cities using TSI-3022 condensation particle counter over a three-year period during health effects of air pollution on susceptible subpopulations

In this study, long-term aerosol particle total number concentration measurements in five metropolitan areas across Europe are presented. The measurements have been carried out in Augsburg, Barcelona, Helsinki, Rome, and Stockholm using the same instrument, a condensation particle counter (TSI model 3022). The results show that in all of the studied cities, the winter concentrations are higher than the summer concentrations. In Helsinki and in Stockholm, winter concentrations are higher by a factor of two and in Augsburg almost by a factor of three compared with summer months. The winter maximum of the monthly average concentrations in these cities is between 10,000 cm(-3) and 20,000 cm(-3), whereas the summer min is approximately 5000-6000 cm(-3). In Rome and in Barcelona, the winters are more polluted compared with summers by as much as a factor of 4-10. The winter maximum in both Rome and Barcelona is close to 100,000 cm(-3), whereas the summer minimum is > 10,000 cm(-3). During the weekdays the maximum of the hourly average concentrations in all of the cities is detected during the morning hours between 7 and 10 a.m. The evening maxima were present in Barcelona, Rome, and Augsburg, but these were not as pronounced as the morning ones. The daily maxima in Helsinki and Stockholm are close or even lower than the daily minima in the more polluted cities. The concentrations between these two groups of cities are different with a factor of about five during the whole day. The study pointed out the influence of the selection of the measurement site and the configuration of the sampling line on the observed concentrations.     

Release of sex pheromone and its precursors in the pine sawfly Diprion pini (Hym., Diprionidae)

Summary. The first identification of a sex pheromone of a pine sawfly (Hymenoptera, Diprionidae) dates back almost thirty years. Since then, female-produced pheromones of over twenty diprionid species have been investigated by solvent extraction followed by separation and identification. However, no study has shown what the females actually release. Collection of airborne compounds using absorbtion on charcoal filter as well as solid phase microextraction (SPME) followed by analysis employing gas chromatography combined with mass spectrometry (GC-MS), revealed an unusual system in Diprion pini, in which the pheromone precursor alcohol, 3,7-dimethyl-2-tridecanol, is released together with acetic, propionic, butyric and isobutyric acids. The corresponding acetate, propionate and butyrate esters of 3,7-dimethyl-2-tridecanol were also found in the samples. All esters were electrophysiologically active, and the propionate and isobutyrate were attractive in trapping experiments. Based on these and earlier reported results, it seems that at least in part of its range, the pheromone response of D. pini is not very specific with regard to the functional group, as long as this is an ester.     

Foraging habitats and migration corridors utilized by a recovering subpopulation of adult female loggerhead sea turtles: implications for conservation

From 1998 to 2008, 68 adult female loggerhead sea turtles (Caretta caretta) were instrumented with platform transmitter terminals at nesting beaches in Georgia, North Carolina (NC) and South Carolina (SC) on the East Coast of the United States of America (30°48′N, 81°28′W to 33°51′N, 77°59′W). The majority of post-nesting loggerheads (N = 42, 62 %) migrated to foraging habitats in the Mid-Atlantic Bight during May–October, with a subsequent migration occurring during November–March to foraging habitats south of Cape Hatteras, NC. Nine (13 %) loggerheads initially foraged in the near-shore, coastal areas of the South Atlantic Bight, but moved to offshore habitats—closer to the Gulf Stream—during November–March, while fourteen (21 %) loggerheads remained in foraging areas along the mid-continental shelf off of the eastern coast of Florida and/or continued southward to Florida Bay and the Bahamas. The present study delineates important, post-nesting foraging habitats and migration corridors where loggerheads may interact with commercial fisheries—providing managers opportunities to develop and implement optimally effective conservation actions for the recovery of this threatened species.     

Persistent organochlorine pesticides,polychlorinated biphenyls,polybrominated diphenyl ethers in fish from coastal waters off Savannah,GA, USA

Contamination profiles of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) were determined in six fish species from three selected regions along coastal waters off Savannah, GA, USA. Concentrations of PCBs were predominant (12–493 ng g^?1 lw) followed by PBDEs (10–337 ng g^?1 lw), OCPs such as DDTs (2.7–153 ng g^?1 lw), chlordanes (3.8–34 ng g^?1 lw), cyclodienes (<0.1–35 ng g^?1 lw), mirex (<0.1–8.6 ng g^?1 lw), γ-hexachlorocyclohexane (<0.1–1.4 ng g^?1 lw), and hexachlorobenzene (<0.1–0.68 ng g^?1 lw). The results indicated no region-specific difference in the contaminants however inter-species as well as intra-species differences were evident. Comparison of DDTs, PCBs, and PBDEs profiles in fish with those from other countries revealed that fish from coastal waters off Savannah contained relatively less concentrations of PCBs and chlorinated pesticides, while PBDE concentrations were comparable or even higher than fish samples from other regions. Polychlorinated biphenyl congeners and chlorinated pesticide tempoal trend data exhibited no increase of contamination levels. The levels of PCBs and chlorinated pesticides in fish from Savannah coastal waters were below the Food and Drug Administrations (FDA) established limits for human consumption.     

Chromium binding by calf thymus nuclei and effects on chromatin

1. No binding of chromium was detected after incubation of calf thymus nuclei with hexavalent chromium up to 0.5 mM.

2. Chromium was readily taken up and tightly bound after incubation with trivalent chromium.

3. In a DNA‐filter binding assay, increasing amounts of chromium and DNA were bound with increasing chromium trichloride concentrations incubated with the nuclei.

4. Treatment with proteinase K abolished the increase in DNA retention induced by trivalent chromium.

5. It is concluded that trivalent chromium is the ultimate genetoxic agent after chromate uptake by living cells.