Dichloromethane Marine Risk Assessment with Special Reference to the Osparcom Region: North Sea

This risk assessment on dichloromethane was carried out specifically for the marine environment, following methodology given in the EU risk assessment Regulation (1488/94) and Guidance Document of the EU New and Existing Substances Regulation (TGD, 1997). The study consists of collection and evaluation of data on effects and environmental concentrations from analytical monitoring programs in large rivers and estuaries in the North Sea area. The risk is indicated by the ratio of 'predicted environmental concentrations' (PEC) to 'predicted no-effect concentrations' (PNEC) for the marine aquatic environment. In total, 23 studies for fish, 17 studies for invertebrates and 6 studies for algae were evaluated. Both acute and chronic toxicity studies were taken into account and appropriate assessment factors used to define a PNEC value of 830 microg/l. Most of the available monitoring data apply to rivers and estuaries and were used to calculate PECs. The most recent data (1983--1995) support a typical PEC for dichloromethane lower than 0.2 microg/l and a worst case PEC of 13.6 microg/l. Dichloromethane is not a 'toxic, persistent and liable to bioaccumulate' substance sensu the Oslo and Paris Conventions for the Prevention of Marine Pollution (OSPAR-DYNAMEC). The calculated PEC/PNEC ratios give margins of 60 to 4000 between the PNEC and PEC, dilution within the sea would further increase these margins. It can be concluded that the present use of dichloromethane does not present a risk to the marine aquatic environment.     

Microbial response to heavy metal-polluted soils: community analysis from phospholipid-linked fatty acids and ester-linked fatty acids extracts

Heavy metal pollution of soil is of concern for human health and ecosystem function. The soil microbial community should be a sensitive indicator of metal contamination effects on bioavailability and biogeochemical processes. Simple methods are needed to determine the degree of in situ pollution and effectiveness of remediating metal-contaminated soils. Currently, phospholipid-linked fatty acids (PLFAs) are preferred for microbial profiling but this method is time consuming, whereas direct soil extraction and transesterification of total ester-linked fatty acids (ELFAs) is attractive because of its simplicity. The 1998 mining acid-metal spill of >4000 ha in the Guadiamar watershed (southwestern Spain) provided a unique opportunity to study these two microbial lipid profiling methods. Replicated treatments were set up as nonpolluted, heavy metal polluted and reclaimed, and polluted soils. Inferences from whole community-diversity analysis and correlations of individual fatty acids with metals suggested Cu, Cd, and Zn were the most important in affecting microbial community structure, along with pH. The microbial stress marker, monounsaturated fatty acids, was significantly lower for reclaimed and polluted soil over nonpolluted soils for both PLFA and ELFA extraction. Another stress marker, the monounsaturated to saturated fatty acids ratio, only showed this for the PLFA. The general fungal marker (18:2omega6c), the arbuscule mycorrhizae marker (16:1omega5c), and iso- and anteiso-branched PLFAs (gram positive bacteria) were suppressed with increasing pollution whereas 17:0cy (gram negative bacteria) increased with metal pollution. For both extraction methods, richness and diversity were greater in nonpolluted soils and lowest in polluted soils. The ELFA method was sensitive for reflecting metal pollution on microbial communities and could be suitable for routine use in ecological monitoring and risk assessment programs because of its simplicity and reproducibility.     

Microbial Fe(III) Reduction in Acidic Mining Lake Sediments after Addition of an Organic Substrate and Lime

To elucidate the role of Fe(III) reduction in mining lake sediments amended with organic substrates, we performed a large (10 m diameter) enclosure experiment in which sediments were amended with Carbokalk, a waste product from sugar industry containing organic carbon and lime. Fe(III) reduction rates were determined monthly by measuring the accumulation of Fe(II) in the sediments in the field. Fe(III) reduction rates were also determined by incubating sediment samples with synthetic Fe(III) oxyhydroxide under in situ temperature in the laboratory. Sulfate reduction was selectively inhibited in the Fe(III) reduction experiments by addition of sodium molybdate. Sulfate reduction was measured by accumulation of reduced inorganic sulfides in the field and by ³⁵S radiotracer using a core injection technique. Sediment incubation and determination of sulfate reduction rates with radiotracer showed that sulfate reduction and direct microbial Fe(III) reduction occured simultaneously in the upper centimeters of the sediments and that both processes contributed to alkalinity generation. However, Fe(III) reduction was the initial process and rates were at least 3.5 fold higher than sulfate reduction rates. The results indicate that the presence of suitable anions for Fe(II) precipitation as carbonate or sulfide is needed in order to prevent loss of potential alkalinity by Fe(II) diffusion and reoxidation in the water column.     

Assessment of the rangelands of southwestern Santiago del Estero, Argentina, for grazing management and research

Native rangelands of the southwest part of the province of Santiago del Estero, Argentina, are a key source of forage for cow-calf operations. The objectives of this study were to delineate the ecosystem units of the area, to describe the associated plant communities and to interpret the role that physical factors and disturbances such as fire and grazing have had in the changes of the structure of these plant communities. This information is needed for developing recommendations for grazing management, for prescribing appropriate improvement practices (e.g. shrub control, prescribed fire) and as guidelines for future research. The ecosystem was divided into smaller units using a hierarchical method, the categories of practical importance being 'range unit' and 'range site'. They represent the catchment and hillslope scale of the water runoff-runon phenomenon, respectively. Vegetation was sampled using a block and cluster sampling design, registering tree, shrub, forb and grass species frequency, and the standing aerial biomass of the herbaceous layer in a sampling unit=1 ha. Environmental data (topographic position, fire frequency, current and past use, and tree and shrub cover) were also registered for each sampling unit. Indirect ordination of sampling units classified according to range units and range sites, and correlation with environmental variables were performed using multidimensional scaling (MDS) as well as the vector fitting technique. Standing forage and stocking rate were estimated from biomass data. Results indicate that 'range site' is the ecosystem unit that should be considered for management purposes since it correlates well with plant communities: tall, hardwood forests are located on upland sites, woodlands are located on midland sites and savannas are located on lowland sites. Dense shrub thickets dominate in areas rated in poor condition, irrespective of range site. Disturbances such as fire and current and past use have a significant positive and negative correlation with range condition, respectively, suggesting that a state and transition model would explain vegetation dynamics better than the succession model. The estimated stocking rate in lowland sites in good condition was 2 ha UG(-1), while in upland sites in poor condition the stocking rate was 90 ha UG(-1). Active (fire, mechanical treatments) rather than passive (grazing management) methods should be used for range improvement in order to achieve the full potential of the ecosystem.     

西安夏季大气亚微米颗粒物化学组成与来源的在线观测研究

西安作为汾渭平原地区最大的城市,大气颗粒物污染形势严峻.2017年夏季期间,在西安市浐灞生态园区运用气溶胶化学组分监测仪,对大气亚微米颗粒物中的非难挥发性组分(NR-PM1)进行了在线监测.观测期间NR-PM1的平均质量浓度为(30.1?±?15.4)μg???m?3.其中有机物含量最高,占NR-PM1总质量浓度的63...     

Wind power projects in Brazil: challenges and opportunities increasing co-benefits and implications for climate and energy policies

The purpose of this article is to analyze the challenges to, and opportunities for, increasing sustainable development (SD) co-benefits delivered by clean development mechanism (CDM) wind power projects in northeastern Brazil and the resulting implications for climate and energy policies. Five methodological phases were met: First, a documentary research was conducted in the main CDM database; second was a literature review, creating the analytical framework and a survey questionnaire needed to assess the SD co-benefits from the projects; third, documentary research was used to enable ex-ante analysis of the SD co-benefits proposed in the CDM Project Design Documents (PDDs); fourth, survey allowed for the analysis of SD co-benefits perceived by project entrepreneurs (ex-post analysis); and finally, a comparison between the ex-ante and ex-post analyses was completed. The results show the importance of carrying out SD co-benefit studies after the implementation of CDM projects in order to learn lessons for new mechanisms of climate governance. The lowest SD co-benefits were water management improvement in the project influence area, soil pollution prevention, health and safety improvements and technology transfer. The greatest opportunities for increasing SD co-benefits come from the environmental licensing process and the strengthening of Corporate Social Responsibility. The greatest challenges are new technology development, stakeholders’ engagement and SD co-benefit audits. We conclude that the improvement of multi-level climate and energy governance plays a key role in increasing SD co-benefits.

     

Sustainability assessment in the Brazilian Amazon: the municipalities of the state of Amapá

Environment, Development and Sustainability - Although sustainability assessment is widely discussed at Brazil, in Brazilian Amazon its use is still little applied, considering this territory is...     

Modified CDKN2B (p15) and CDKN2A (p16) DNA methylation profiles in urban pesticide applicators

Environmental Science and Pollution Research - Gene-specific changes in DNA methylation by pesticides in occupationally exposed populations have not been studied extensively. Of particular concern...     

Accumulation of heavy metals in native Andean plants: potential tools for soil phytoremediation in Ancash (Peru)

Metal contamination is a recurring problem in Peru, caused mainly by mine tailings from a past active mining activity. The Ancash region has the largest number of environmental liabilities, which mobilizes high levels of metals and acid drainages into soils and freshwater sources, posing a standing risk on human and environmental health. Native plant species spontaneously growing on naturally acidified soils and acid mine tailings show a unique tolerance to high metal concentrations and are thus potential candidates for soil phytoremediation. However, little is known about their propagation capacity and metal accumulation under controlled conditions. In this study, we aimed at characterizing nine native plant species, previously identified as potential hyperaccumulators, from areas impacted by mine tailings in the Ancash region. Plants were grown on mine soils under greenhouse conditions during 5 months, after which the concentration of Cd, Cu, Ni, Pb, and Zn was analyzed in roots, shoots, and soils. The bioaccumulation (BAF) and translocation factor (TF) were calculated to determine the amount of each metal accumulated in the roots and shoots and to identify which species could be better suited for phytoremediation purposes. Soil samples contained high Cd (6.50–49.80 mg/kg), Cu (159.50–1187.00 mg/kg), Ni (3.50–8.70 mg/kg), Pb (1707.00–4243.00 mg/kg), and Zn (909.00–7100.00 mg/kg) concentrations exceeding national environmental quality standards. After exposure to mine tailings, concentrations of metals in shoots were highest in Werneria nubigena (Cd, 16.68 mg/kg; Cu, 41.36 mg/kg; Ni, 26.85 mg/kg; Zn, 1691.03 mg/kg), Pennisetum clandestinum (Pb, 236.86 mg/kg), and Medicago lupulina (Zn, 1078.10 mg/kg). Metal concentrations in the roots were highest in Juncus bufonius (Cd, 34.34 mg/kg; Cu, 251.07 mg/kg; Ni, 6.60 mg/kg; Pb, 718.44 mg/kg) and M. lupulina (Zn, 2415.73 mg/kg). The greatest BAF was calculated for W. nubigena (Cd, 1.92; Cu, 1.20; Ni, 6.50; Zn, 3.50) and J. bufonius (Ni, 3.02; Zn, 1.30); BCF for Calamagrostis recta (Cd, 1.09; Cu, 1.80; Ni, 1.09), J. bufonius (Cd, 3.91; Cu, 1.79; Ni, 18.36), and Achyrocline alata (Ni, 137; Zn, 1.85); and TF for W. nubigena (Cd, 2.36; Cu, 1.70; Ni, 2.42; Pb, 1.17; Zn, 1.43), A. alata (Cd, 1.14; Pb, 1.94), J. bufonius (Ni, 2.72; Zn, 1.63), and P. clandestinum (Zn, 1.14). Our results suggest that these plant species have a great potential for soil phytoremediation, given their capability to accumulate and transfer metals and their tolerance to highly metal-polluted environments in the Andean region.     

Do tailings from the Mariana,MG (Brazil), disaster affect the initial development of millet,maize, and sorghum?

Environmental Science and Pollution Research - The collapse of the Fundão dam in Mariana, MG, in 2015 resulted in the overflow of more than 50 million m3 of mud containing mine tailings,...