Linking Climate Trends to Population Dynamics in the Baltic Ringed Seal: Impacts of Historical and Future Winter Temperatures

A global trend of a warming climate may seriously affect species dependent on sea ice. We investigated the impact of climate on the Baltic ringed seals (Phoca hispida botnica), using historical and future climatological time series. Availability of suitable breeding ice is known to affect pup survival. We used detailed information on how winter temperatures affect the extent of breeding ice and a climatological model (RCA3) to project the expected effects on the Baltic ringed seal population. The population comprises of three sub-populations, and our simulations suggest that all of them will experience severely hampered growth rates during the coming 90 years. The projected 30 730 seals at the end of the twenty-first century constitutes only 16 % of the historical population size, and thus reduced ice cover alone will severely limit their growth rate. This adds burden to a species already haunted by other anthropogenic impacts.     

Activated carbon amendment to sequester PAHs in contaminated soil: a lysimeter field trial

Activated carbon (AC) amendment is an innovative method for the in situ remediation of contaminated soils. A field-scale AC amendment of either 2% powder or granular AC (PAC and GAC) to a PAH contaminated soil was carried out in Norway. The PAH concentration in drainage water from the field plot was measured with a direct solvent extraction and by deploying polyoxymethylene (POM) passive samplers. In addition, POM samplers were dug directly in the AC amended and unamended soil in order to monitor the reduction in free aqueous PAH concentrations in the soil pore water. The total PAH concentration in the drainage water, measured by direct solvent extraction of the water, was reduced by 14% for the PAC amendment and by 59% for GAC, 12 months after amendment. Measurements carried out with POM showed a reduction of 93% for PAC and 56% for GAC. The free aqueous PAH concentration in soil pore water was reduced 93% and 76%, 17 and 28 months after PAC amendment, compared to 84% and 69% for GAC. PAC, in contrast to GAC, was more effective for reducing freely dissolved concentrations than total dissolved ones. This could tentatively be explained by leaching of microscopic AC particles from PAC. Secondary chemical effects of the AC amendment were monitored by considering concentration changes in dissolved organic carbon (DOC) and nutrients. DOC was bound by AC, while the concentrations of nutrients (NO(3), NO(2), NH(4), PO(4), P-total, K, Ca and Mg) were variable and likely affected by external environmental factors.     

Integrating economic and biophysical data in assessing cost-effectiveness of buffer strip placement

The European Union Water Framework Directive (WFD) requires Member States to set water quality objectives and identify cost-effective mitigation measures to achieve "good status" in all waters. However, costs and effectiveness of measures vary both within and between catchments, depending on factors such as land use and topography. The aim of this study was to develop a cost-effectiveness analysis framework for integrating estimates of phosphorus (P) losses from land-based sources, potential abatement using riparian buffers, and the economic implications of buffers. Estimates of field-by-field P exports and routing were based on crop risk and field slope classes. Buffer P trapping efficiencies were based on literature metadata analysis. Costs of placing buffers were based on foregone farm gross margins. An integrated optimization model of cost minimization was developed and solved for different P reduction targets to the Rescobie Loch catchment in eastern Scotland. A target mean annual P load reduction of 376 kg to the loch to achieve good status was identified. Assuming all the riparian fields initially have the 2-m buffer strip required by the General Binding Rules (part of the WFD in Scotland), the model gave good predictions of P loads (345-481 kg P). The modeling results show that riparian buffers alone cannot achieve the required P load reduction (up to 54% P can be removed). In the medium P input scenario, average costs vary from ￡38 to ￡176 kg P at 10% and 54% P reduction, respectively. The framework demonstrates a useful tool for exploring cost-effective targeting of environmental measures.     

The use of physiological characteristics for comparison of organic compounds phytotoxicity

The influence of intact (FLT) and photomodified (phFLT) fluoranthene (0.05, 0.5 and 5 μmol l⁻¹) and herbicide Basagran (5, 20, 35 and 50 nmol l⁻¹) on the germination, growth of seedlings and photosynthetic processes in pea plants (Pisum sativum L., cv. Garde) was investigated. The germination was significantly inhibited already by the lowest concentration (0.05 μmol l⁻¹) of FLT and phFLT, while Basagran caused inhibition only in higher concentrations (35 and 50 nmol l⁻¹). The growth of roots was significantly inhibited by higher concentration 5 μmol l⁻¹ of both FLT and phFLT and the shoot of seedlings was significantly influenced only by photomodified form. The length of root and shoot was inhibited already by concentration 5 nmol l⁻¹ of Basagran. Organic compounds applied on chloroplasts suspension influenced primary photochemical processes of photosynthesis. In chlorophyll fluorescence parameters, the significant increase of F₀ values and the decrease of F_V/F_M and Φ_II values by application of FLT (0.5 and 5 μmol l⁻¹) and phFLT (0.05, 0.5 and 5 μmol l⁻¹) was recorded. The maximum capacity of PSII (F_V/F_M) was influenced by the highest (50 nmol l⁻¹) and the effective quantum yield of PSII (Φ_II) already by the lowest (5 nmol l⁻¹) concentration of Basagran. Hill reaction activity decreased and was significantly inhibited by higher concentration (0.5 and 5 μmol l⁻¹) of FLT and phFLT and already by the lowest concentration (5 nmol l⁻¹) of Basagran.     

Characterisation of esterases as potential biomarkers of pesticide exposure in the lugworm Arenicola marina (Annelida: Polychaeta)

Here, we identify and characterise cholinesterase (ChE) and carboxylesterase (CbE) activities in the body tissues of the sediment dwelling worm Arenicola marina. Exposure to the organophosphorus pesticide azamethiphos yielded an in vitro IC50 of 5 microg l(-1) for propionylcholinesterase (PChE). PChE was significantly inhibited in vivo after a 10 day exposure to 100 microg l(-1) azamethiphos, equivalent to the recommended aquatic application rate (ANOVA; F=2.75, P=0.033). To determine sensitivity to environmental conditions, A. marina were exposed for 10 days to field collected sediments. PChE activity was significantly lower in worms exposed to sediments from an estuary classified to be at high risk from point source pollution by the UK Environment Agency (ANOVA; F=15.33, P<0.001). Whilst causality cannot be directly attributed from these latter exposures, they provide an important illustration of the potential utility of esterase activity as a biomarker of environmental quality in this ecologically relevant sentinel species.     

Changes in soil chemical and microbiological properties during 4 years of application of various organic residues

A 4-year field trial was established in eastern Sweden to evaluate the effects of organic waste on soil chemical and microbiological variables. A simple crop rotation with barley and oats was treated with either compost from household waste, biogas residue from household waste, anaerobically treated sewage sludge, pig manure, cow manure or mineral fertilizer. All fertilizers were amended in rates corresponding to 100kgNha(-1)year(-1). The effects of the different types of organic waste were evaluated by subjecting soil samples, taken each autumn 4 weeks after harvest, to an extensive set of soil chemical (pH, Org-C, Tot-N, Tot-P, Tot-S, P-AL, P-Olsen, K-AL, and some metals) and microbiological (B-resp, SIR, microSIR active and dormant microorganisms, PDA, microPDA, PAO, Alk-P and N-min) analyses. Results show that compost increased pH, and that compost as well as sewage sludge increased plant available phosphorus; however, the chemical analysis showed few clear trends over the 4 years and few clear relations to plant yield or soil quality. Biogas residues increased substrate induced respiration (SIR) and, compared to the untreated control amendment of biogas residues as well as compost, led to a higher proportion of active microorganisms. In addition, biogas residues increased potential ammonia oxidation rate (PAO), nitrogen mineralization capacity (N-min) as well as the specific growth rate constant of denitrifiers (microPDA). Despite rather large concentrations of heavy metals in some of the waste products, no negative effects could be seen on either chemical or microbiological soil properties. Changes in soil microbial properties appeared to occur more rapidly than most chemical properties. This suggests that soil microbial processes can function as more sensitive indicators of short-term changes in soil properties due to amendment of organic wastes.     

Influence of Technological Process on Biodegradation of PVA/Waxy Starch Blends in an Aerobic and Anaerobic Environment

Improving biodegradability of PVA/starch blends is a reality already documented by a number of works. Admittedly, mechanical properties of products (for example, tensile strength) are somewhat worse, but suitable composition optimizing or chemical modifying of starch may eliminate the problem to a large degree. This work is an attempt to find another potential effect influencing biodegradability, that of technological procedure for producing films from these blends on an extruder. The procedure with a so-called pre-extrusion step (two-stage) and dry-blend (single-stage) produced blends of slightest differences in achieved biodegradability (virtually within limits of experimental error) in aerobic (76 vs. 79%) as well as anaerobic breakdown (48 vs. 52%). Conversely, morphological analysis exhibited superior homogeneity of films prepared by the two-stage process; their tensile strength was also higher.     

Attitudes and Perceptions about Ecological Resources and Hazards of People Living Aroung the Savannah River Site

Although considerable attention is devoted to environmental monitoring and assessment with respect to both pollutants and the status of particular plant or animal populations, less attention is devoted to assessing people's attitudes about the relative importance of ecological resources. In this paper we examine the attitudes and perceptions about ecological resources of people living around the Department of Energy's Savannah River Site (SRS), in South Carolina. Our overall hypothesis is that people who are directly affected by the possible outcomes and consequences of a particular hazard (i.e., those people employed at SRS) will undervalue the risks and overvalue the potential benefits from future land uses that favor continued site activity, compared to people who live near but are not employed at SRS. We interviewed 286 people attending the Aiken Trials horse show on 14 March 1997. There were few gender differences, although men hunted and fished more than women, women ranked three environmental concerns as more severe than did men, and women were more concerned about the effect of SRS on property values. Maintenance of SRS as a National Environmental Research Park ranked first as a future land use; nuclear production ranked second, followed by hunting and hiking. Only residential development ranked very low as a future land use. There were many differences as a function of employment history at SRS: 1) people who work at SRS think that the federal government should spend funds to clean up all nuclear facilities, and they think less money should be spent on other environmental problems than did non-employees, 2) people who work at SRS ranked continued current uses of SRS higher than did people who never worked at SRS, and 3) people who work at SRS are less concerned about the storage of nuclear material or accidents at the site than are people who never worked at the site.     

Urban mining: hibernating copper stocks in local power grids

Large technical systems serving the everyday needs of people, such as water supply systems, power grids or communication networks, are rich in accumulated metals. Over time, parts of these systems have been taken out of use without the system infrastructure being removed from its original location. Such metal stocks in hibernation thus constitute potential resource reservoirs accessible for recovery. In this paper, obsolete stocks of copper situated in the local power grids of two Swedish cities are quantified. Emphasis is also on economic conditions for extracting such “hibernating” cables. The results show that on a per customer basis, the two power grids contain similar amounts of copper, i.e. 0.04–0.05 tonnes per subscriber. However, the share of the copper stock that is in hibernation differs between the grids. In the larger grid of Gothenburg, almost 20% of the copper accumulated in the grid is no longer in use, while the obsolete share does not exceed 5% in the city of Linköping. For managers of local power grids, recovery of hibernating cables could be beneficial if integrated with other maintenance work on the grid. At the present price of copper, however, separate recovery of obsolete cables is not economically justified.     

Groundwater contamination by microbiological and chemical substances released from hospital wastewater: Health risk assessment for drinking water consumers

Contamination of natural aquatic ecosystems by hospital wastewater is a major environmental and human health issue. Disinfectants, pharmaceuticals, radionuclides and solvents are widely used in hospitals for medical purposes and research. After application, some of these substances combine with hospital effluents and, in industrialised countries, reach the municipal sewer network. In certain developing countries, hospitals usually discharge their wastewater into septic tanks equipped with diffusion wells. The discharge of chemical compounds from hospital activities into the natural environment can lead to the pollution of water resources and risks for human health. The aim of this article is to present: (i) the steps of a procedure intended to evaluate risks to human health linked to hospital effluents discharged into a septic tank equipped with a diffusion well; and (ii) the results of its application on the effluents of a hospital in Port-au-Prince. The procedure is based on a scenario that describes the discharge of hospital effluents, via septic tanks, into a karstic formation where water resources are used for human consumption. COD, Chloroform, dichlomethane, dibromochloromethane, dichlorobromomethane and bromoform contents were measured. Furthermore, the presence of heavy metals (chrome, nickel and lead) and faecal coliforms were studied. Maximum concentrations were 700 NPP/100 ml for faecal coliforms and 112 mg/L for COD. A risk of infection of 10^? 5 infection per year was calculated. Major chemical risks, particularly for children, relating to Pb(II), Cr(III), Cr(VI) and Ni(II) contained in the ground water were also characterised. Certain aspects of the scenario studied require improvement, especially those relating to the characterisation of drugs in groundwater and the detection of other microbiological indicators such as protozoa, enterococcus and viruses.