Exploring the risks and benefits of flexibility in biodiversity offset location in a case study of migratory shorebirds

Biodiversity offsets aim to counterbalance the residual impacts of development on species and ecosystems. Guidance documents explicitly recommend that biodiversity offset actions be located close to the location of impact because of higher potential for similar ecological conditions, but allowing greater spatial flexibility has been proposed. We examined the circumstances under which offsets distant from the impact location could be more likely to achieve no net loss or provide better ecological outcomes than offsets close to the impact area. We applied a graphical model for migratory shorebirds in the East Asian–Australasian Flyway as a case study to explore the problems that arise when incorporating spatial flexibility into offset planning. Spatially flexible offsets may alleviate impacts more effectively than local offsets; however, the risks involved can be substantial. For our case study, there were inadequate data to make robust conclusions about the effectiveness and equivalence of distant habitat-based offsets for migratory shorebirds. Decisions around offset placement should be driven by the potential to achieve equivalent ecological outcomes; however, when considering more distant offsets, there is a need to evaluate the likely increased risks alongside the potential benefits. Although spatially flexible offsets have the potential to provide more cost-effective biodiversity outcomes and more cobenefits, our case study showed the difficulty of demonstrating these benefits in practice and the potential risks that need to be considered to ensure effective offset placement.     

地下水开发引起的环境问题与治理

随着社会经济的飞速发展,人民生活对水资源的需求量日益增加,水资源开发已然成为备受社会各界关注的一项话题。而若是未能重视资源开发合理性与适宜性,必然会造成一定的环境污染。本文阐述了我国水资源开发与利用现状,分析了地下水开发引起的环境问题,并探究了新形势下治理地下水开发环境问题的有效对策。     

Contamination characteristics of trace metals in dust from different levels of roads of a heavily air-polluted city in north China

Concentrations of eight trace metals (TMs) in road dust (RD) (particles?<?25 μm) from urban areas of Xinxiang, China, were determined by inductively coupled plasma mass spectrometry. The geometric mean concentrations of Zn, Mn, Pb, As, Cu, Cr, Ni and Cd were 489, 350, 114, 101, 60.0, 39.7, 31.6, and 5.1 mg kg^?1, respectively. When compared with TM levels in background soil, the samples generally display elevated TM concentrations, except for Cr and Mn, and for Cd the enrichment value was 69.6. Spatial variations indicated TMs in RD from park path would have similar sources with main roads, collector streets and bypasses. Average daily exposure doses of the studied TMs were about three orders of magnitude higher for hand-to-mouth ingestion than dermal contact, and the exposure doses for children were 9.33 times higher than that for adults. The decreasing trend of calculated hazard indexes (HI) for the eight elements was As?>?Pb?>?Cr?>?Mn?>?Cd?>?Zn?>?Ni?>?Cu for both children and adults.     

Effects of T-2 toxin on histopathology,fatty acid and water distribution of shrimp (Litopenaeus vannamei) muscle

T-2 toxin (T-2), one of the naturally occurring mycotoxins, often accumulates in aquatic animals from contaminated feed. Shrimp (n?=?30 per group) were fed with different concentrations (0, 0.5, 1.5, 4.5 and 13.5?mg kg^?1) of T-2 for 20?days. Changes in histopathology, fatty acid and water distribution of shrimp muscle were analyzed. Histopathology of shrimp muscle showed dose-dependent marked degenerative and necrotic changes on exposure to dietary T-2. The T-2 significantly (P?<?0.05) affected the muscle fatty acid composition. ∑SFA, ∑MUFA and ∑PUFA initially decreased and then increased slowly in the high-dosed groups. C16:0, C18:1n-9 and C18:2n-6 were the main saturated fatty acid (SFA), monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA), respectively. Also, T-2 significantly affected water distribution in shrimp muscle. High doses of T-2 reduced free water content, resulting in a reduction in the water holding capacity and hence changes to the shrimp muscle quality. Collectively, these results illustrated that T-2 significantly affects the fatty acid and water distribution, and also muscle histopathology, all of which would result in a reduction in the quality and nutritional value of shrimp.     

Effects of exogenous acylated homoserine lactones on biofilms in biofilters for gaseous toluene treatment

● Biofilm formation was enhanced by exogenous AHLs. ● EPS production and microbial adhesive strength of biofilm were promoted. ● Exogenous AHLs improved the performance of biofilters treating toluene. Biofilters are typical biofilm reactors, and they usually have poor biofilm formation resulting in limited reactor performance. Exogenous acylated homoserine lactones (AHLs) can enhance biofilm formation in many bioreactors based on quorum sensing regulation. However, their effect on biofilm in biofilters utilized for volatile organic compound (VOC) removal is unknown and needs to be investigated. In this study, the effects of the exogenous AHLs on biofilters for gaseous toluene removal were investigated. Analysis of biofilms in biofilters showed that the addition of exogenous AHLs considerably enhanced biofilm growth; the average biofilm concentration increased by 18%. Furthermore, the average biofilm coverage proportions in biofilters with and without exogenous AHLs were 17 % and 13 %, respectively, demonstrating the positive effect of exogenous AHLs on biofilm coverage. In particular, exogenous AHLs promoted the production of extracellular polymeric substances and the microbial adhesive strength of the biofilm. In addition, the exogenous AHLs showed no significant effect on the gaseous toluene removal efficiency of the biofilter. These results show that exogenous AHLs can enhance biofilm formation and can guide the application of exogenous AHLs in VOC biofilters.     

Synthesis of branched allylic sulfones by regioselective boron-catalysed hydrosulfonylation

Environmental Chemistry Letters - Branched allylic sulfones are scaffolds widely distributed in bioactive molecules and organic functional materials. The synthesis of allylic sulfones has been...     

The associations of air pollution exposure during pregnancy with fetal growth and anthropometric measurements at birth: a systematic review and meta-analysis

Environmental Science and Pollution Research - Fetal growth has been demonstrated to be an important predictor of perinatal and postnatal health. Although the effects of maternal exposure to air...     

聚苯乙烯/CdS/TiO_2双壳层核壳纳米颗粒可见光催化降解甲基橙

采用溶胶-凝胶法,在聚苯乙烯(PS)/CdS核壳纳米颗粒表面包覆致密TiO_2层,制备出具有双壳层结构的PS/CdS/TiO_2纳米复合颗粒,考察了制备条件对材料结构的影响,并利用甲基橙溶液对其光催化性能进行了评价。SEM、TEM、XRD和FTIR分析结果表明,制得的微球单分散性良好,壳层包覆完整,厚度均匀。PS/CdS/TiO_2制备的适宜反应时间为12~18 h,适宜反应pH为7~9。PS/CdS/TiO_2较PS/CdS具有更为优异的可见光催化性能。     

Depth perception,dark adaptation,vigilance and accident proneness of Chinese coal mine workers

To explore the relationships between human factors and accident proneness of coal mine workers, the depth perception, dark adaptation and vigilance abilities of 239 Chinese coal mine workers were tested and their accident proneness was surveyed with an accident proneness questionnaire. The results indicated that dark adaptation and vigilance abilities of the mine workers declined with increasing age. Vigilance had a significant negative relationship with accident proneness. There were significant differences in vigilance between coal mine workers doing different types of work. Individual difference in vigilance was relevant to the type of work that an individual did in a coal mine. The dark adaptation index had a significant positive relationship with accident proneness. Coal mine workers with weaker dark adaptation ability were also more accident prone. Some ergonomics recommendations concerning coal mine safety management in China are proposed.     

城市安全生产风险评估调研和信息处理方法研究

为城市安全生产风险评估调研工作的合理有序开展,本文结合实际案例归纳了城市安全生产风险评估调研的目的、范围、内容和流程,具体介绍了走访座谈法、常专结合法、函件调研法等信息采集方法,总结了综合归纳法和逻辑处理法等信息处理方法。结果表明,在调研的不同阶段运用不同的调研方法可有效获取城市安全生产风险源信息及安全生产基本信息,为城市安全生产风险评估工作奠定坚实的信息数据资料支撑。