Stoffflussanalyse von quartären Ammoniumverbindungen für die Schweiz

Background, aim, and scope Compared to other micropollutants such as pesticides or pharmaceuticals, less attention has been paid to biocides so far. A prioritisation of the biocides currently used in Switzerland in terms of pollution of waters revealed that quaternary ammonium compounds (QAC), the isothiazolinones chloromethylisothiazolinone and benzisothiazolinone as well as Irgarol exhibit the highest risk potential. The QAC benzalkoniumchloride (BAC) and didecyldimethylammoniumchloride (DDAC-C10) are used in considerable amounts and have a high biological activity. Materials and methods The emissions of selected QAC in waters and soil and the predicted environmental concentrations (PECs) were estimated by means of a substance flow analysis (SFA). The study was based on data from the Swiss products register, on literature, contacts to producers and users as well as on own assumptions. Results and discussion The consumption of BAC (four homologues) and DDAC-C10 in biocidal applications in Switzerland amounts to 90 and 30 tons annually. The most important applications are disinfectants for public health areas, food and feed areas as well as wood preservatives. The total emissions to the environment of all five substances account for approximately 11?t/a. The PECs in surface waters and sediments vary from values slightly lower than the predicted no-effect concentration (PNEC) to roughly three orders of magnitude below the PNEC. However, concentrations above the PNEC are possible at certain locations, particularly downstream of wastewater treatment plants (WWTP) effluents and sewer overflows. Effects on aquatic organisms can therefore not be excluded. Three BAC homologues could not be assessed, as there were no PNEC values available. Conclusions The contribution of emissions from WWTP (punctual emissions) to the environment is only about one tenth and relatively low compared to diffuse emissions. This means that measures for the emission reduction focussing only on end-of-pipe solutions in WWTP will not reduce the emissions significantly. Moreover, for the evaluation of measures, attention has to be paid to the fact that biocides such as the selected QAC are often also applied in non-biocidal applications (e.?g. three times higher volumes in the case of BAC). Recommendations and perspectives SFA serves as a useful tool for early recognition of environmental problems caused by chemicals. This allows recommending appropriate risk reduction measures in the production, the use and the end-of-life phase. It is advisable to use the SFA already in the development stage of chemicals and later on as a quality control tool. The relevant sources of chemicals and sinks in the environment can thus be determined in complex systems, even in absence of extensive measurements or product registers with consumption figures by means of estimations and scenarios.     

Bayesian Small Area Models for Assessing Wildlife Conservation Risk in Patchy Populations

Abstract:  Species conservation risk assessments require accurate, probabilistic, and biologically meaningful maps of population distribution. In patchy populations, the reasons for discontinuities are not often well understood. We tested a novel approach to habitat modeling in which methods of small area estimation were used within a hierarchical Bayesian framework. Amphibian occurrence was modeled with logistic regression that included third-order drainages as hierarchical effects to account for patchy populations. Models including the random drainage effects adequately represented species occurrences in patchy populations of 4 amphibian species in the Oregon Coast Range (U.S.A.). Amphibian surveys from other locations within the same drainage were used to calibrate local drainage-scale effects. Cross-validation showed that prediction errors for calibrated models were 77% to 86% lower than comparable regionally constructed models, depending on species. When calibration data were unavailable, small area and regional models performed similarly, although poorly. Small area estimation models complement wildlife ecology and habitat studies, and can help managers develop a regional picture of the conservation status for relatively rare species.     

Microbial detoxification of metalaxyl in aquatic system

Four microorganisms, Pseudomonas sp. （ER2）, Aspergillus niger （ER6）, Cladosporium herbarum （ER4） and Penicilluim sp. （ER3）, were isolated from cucumber leaves previously treated with metalaxyl using enrichment technique. These isolates were evaluated for detoxification of metalaxyl at the recommended dose level in aquatic system. The effect of pH and temperature on the growth ability of the tested isolates was also investigated by measuring the intracellular protein and mycelia dry weight for bacterial and fungal isolates, respectively. Moreover, the toxicity of metalaxyl after 28 d of treatment with the tested isolates was evaluated to confirm the complete removal of any toxic materials （metalaxyl and its metabolites）. The results showed that the optimum degree pH for the growth of metalaxyl degrading isolates （bacterial and fungal isolates） was 7. The temperature 30℃ appeared to be the optimum degree for the growth of either fungal or bacterial isolates. The results showed that Pseudomonas sp. （ER2） was the most effective isolate in metalaxyl degradation followed by Aspergillus niger （ER6）, Cladosporium herbarum （ER4） and Penicilluim sp. （ER3）, respectively. There is no toxicity of metalaxyl detected in the supematant after 28 d of treatment with Pseudomonas sp. （ER2）. The results suggest that bioremediation by Pseudomonas sp. （ER2） isolate was considered to be effective method for detoxification of metalaxyl in aqueous media.     

Consumption of rice and fish in an electronic waste recycling area contributes significantly to total daily intake of mercury

<正>Mercury is a global pollutant due to its widespread use,emission,and long-range transport(Blum,2013;Pacyna et al.,2010).It is considered a priority pollutant due to its neurological toxicity,persistence,and bioaccumulation(Pacyna et al.,2010;Sharma et al.,2015).Mercury pollution can occur when products that contain mercury are improperly disposed of and mercury is released into the air,water,and soil(Zhang and Wong,2007).An estimated 22%of the annual world usage of mercury is in electrical equipment such as batteries,thermometers,and discharge lamps,and electronic devices such as monitors and     

Factors of Dynamics of Plankton Crustacean Communities under Eutrophic Conditions

Russian Journal of Ecology - It has been shown that the main drivers of the dynamics of cladoceran and copepod abundances can be predators (fish), the quantity and/or quality of food in terms of...     

The Effect of Vaccinium vitis-idaea on Properties of Mountain-Meadow Soil under Alpine Lichen Heath

Russian Journal of Ecology - Abstract—The study of the effect of mycorrhiza symbiosis on the transformation of carbon and nitrogen compounds in soils is important in view of the necessity to...     

Temporal and Spatial Variations of Phytoplankton Community Structure in Lake Erhai,a Chinese Plateau Lake,with Reference to Environmental Factors

Russian Journal of Ecology - Temporal and spatial variations of phytoplankton community in Lake Erhai were investigated from May 2010 to April 2011. A total of 124 species belonging to 8 phyla and...     

粤港澳大湾区甲醛污染的时空特征研究

利用Aura卫星搭载的臭氧观测仪（ozone monitoring instrument,OMI）反演的甲醛（HCHO）柱密度数据,分析自2005年以来粤港澳大湾区（Guangdong-Hong Kong-Macao Greater Bay Area,GBA）HCHO的空间分布特征、变化趋势及其影响因素。研究结果表明HCHO呈现明显的增长趋势,2005年和2019年区域年平均分别为1.4840 mol·cm⁻²和1.7983 mol·cm⁻²,2005—2019年增长了0.3143 mol·cm⁻²,约为21.17%。粤港澳大湾区HCHO演化过程存在11个月的主振荡周期。HCHO月变化在时空上呈现明显差异,最大值和最小值分别出现在7月和1月,多年平均值分别为1.9824 mol·cm⁻²和1.1728 mol·cm⁻²。6月空间异质性最为明显,最大值和最小值分别为2.6842 mol·cm⁻²和1.0849 mol·cm⁻²。粤港澳大湾区HCHO污染严重的区域主要出现在中部,如中山市、佛山市和广州市,多年平均值高达1.9938 mol·cm⁻²。低值区主要在区域四周,特别是在惠州市,多年平均值约为1.3522 mol·cm⁻²。HCHO增长率在空间上呈现明显差异,增长量的变化范围为−0.1374—0.6833 mol·cm⁻²,增长率为−7.20%—52.53%。大部分区域的HCHO呈增长趋势,而在广州市部分地区出现减少,最大的减少量为−1.3742 mol·cm⁻²,约为−7.20%。从城市尺度来看,所有城市的HCHO均出现增长,增长量和增长率最大的是惠州市,分别为0.3863 mol·cm⁻²和28.27%;其次是江门市,分别为0.3411 mol·cm⁻²和23.71%;最小的是香港,分别为0.9093 mol·cm⁻²和6.52%。