Maternal transfer of brominated flame retardants in zebrafish (Danio rerio)

In many species reproduction and embryonic development have been shown to be sensitive to environmental contaminants. Understanding embryonic exposure to environmental contaminants is thus highly important. In this study concentrations of brominated flame retardants (BFRs) were measured in zebrafish eggs after parental exposure for 42 days via the diet. Zebrafish were exposed to two doses of eleven structurally-diverse BFRs. Eight BFRs were detected in the female zebrafish and maternal transfer to eggs was evident for all eight compounds. The highest concentrations in eggs were observed for hexabromocyclododecane (HBCD) and 2,4,4'-tribromodiphenyl ether (BDE 28), followed by 2,2',3,4,4',5',6-heptabromodiphenyl ether (BDE 183) and tetrabromobisphenol A 2,3-dibromopropyl ether (TBBPA DBPE). Five potential BFR metabolites were tentatively identified in female fish and maternal transfer was observed also for these compounds. The lipid adjusted concentrations in eggs were significantly higher than the concentrations in female fish for several of the BFRs. Further, the results showed a generally higher transfer in the lower exposure level and also indicated a dependency on the physico-chemical properties of the compounds.     

Photocatalytic and combined anaerobic-photocatalytic treatment of textile dyes

A photocatalytic process based on immobilized titanium dioxide was used to treat crude solutions of azo, anthraquinone and phthalocyanine textile dyes. In addition, the process was applied to the treat autoxidized chemically reduced azo dyes, i.e. representatives of recalcitrant dye residues after biological sequential anaerobic-aerobic treatment. Photocatalysis was able to remove more than 90% color from crude as well as autoxidized chemically reduced dye solutions. UV-absorbance and COD were also removed but to a lower extent (50% in average). The end products of photocatalytic treatment were not toxic toward methanogenic bacteria. The results demonstrate that photocatalysis can be used as a pre- or post-treatment method to biological anaerobic treatment of dye-containing textile wastewater.     

Biochemical effects of clomazone herbicide on piava (Leporinus obtusidens)

This study aims to verify the effects of the clomazone concentration used in rice fields on acetylcholinesterase (AChE), thiobarbituric acid reactive substances (TBARS), protein carbonyl and catalase activity in tissues of piava (Leporinus obtusidens). LC(50)-96h was 5.0 mg L(-1) and the fish were exposed to 1/10 of LC(50)-96 h: 0.5 mg L(-1) of clomazone for 96 and 192h. The same parameters were also assayed after a recovery period of 192 h in clean water. AChE activity was reduced only in the brain and heart of fish exposed for 96 h. AChE activity was decreased in the brain, muscle and heart tissues after 192 h of exposure. After 192 h of recovery period, AChE activity remained diminished in brain and muscle and showed a decrease in eye. However, after 192 h of recovery, AChE activity in heart was recovered. Fish showed increased TBARS levels in brain at all experimental periods. TBARS levels decreased in liver and muscle tissues after 192 h of exposure. The increase in muscle TBARS persisted in fish transferred to clean water. Protein carbonyl in the liver was increased in all periods studied including the recovery period. Catalase activity was reduced during all periods. The present study demonstrates the occurrence of disorders in AChE, TBARS, protein carbonyl and catalase activity in piava. The results also show changes in fish after exposure to an environmentally relevant concentration of clomazone. Most effects observed persisted after the recovery period. Thus, these parameters may be used to monitor clomazone toxicity in fish.     

Monitoring PCDD/Fs, PCBs and metals in the ambient air of an industrial area of Catalonia, Spain

In 2005 and 2006, the levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs) and metals (As, Be, Cd, Co, Cr, Cu, Mn, Ni, Pb, Sn, Tl and V) were measured in air samples collected in an industrial area of Sant Adrià del Besòs (Barcelona, Catalonia, Spain) where a municipal solid waste incinerator (MSWI) is placed, and in a background/control area. In general terms, concentrations of all environmental pollutants were higher at the industrial site. No significant seasonal/temporal variations were observed in any of the areas. No Pearson correlation was found between the PCDD/F concentrations and the environmental conditions of the two sampling periods considered. Principal component analyses (PCA) were performed to get information on the relationship among samples, pollutants, and emission sources. The results indicate that the MSWI of S. Adrià de Besòs is not a significant emission source of the above compounds for the area under its direct influence. Moreover, a notable difference in the PCDD/F congener profiles was found between ambient air and stack gas emissions, indicating that the current levels of PCDD/Fs are more related to other potential emissions sources rather than to those from the MSWI.     

Risk assessment and prioritisation of contaminated sites on the catchment scale

Contaminated sites pose a significant threat to groundwater resources worldwide. Due to limited available resources a risk-based prioritisation of the remediation efforts is essential. Existing risk assessment tools are unsuitable for this purpose, because they consider each contaminated site separately and on a local scale, which makes it difficult to compare the impact from different sites. Hence a modelling tool for risk assessment of contaminated sites on the catchment scale has been developed. The CatchRisk screening tool evaluates the risk associated with each site in terms of its ability to contaminate abstracted groundwater in the catchment. The tool considers both the local scale and the catchment scale. At the local scale, a flexible, site specific leaching model that can be adjusted to the actual data availability is used to estimate the mass flux over time from identified sites. At the catchment scale, a transport model that utilises the source flux and a groundwater model covering the catchment is used to estimate the transient impact on the supply well. The CatchRisk model was tested on a groundwater catchment for a waterworks north of Copenhagen, Denmark. Even though data scarcity limited the application of the model, the sites that most likely caused the observed contamination at the waterworks were identified. The method was found to be valuable as a basis for prioritising point sources according to their impact on groundwater quality. The tool can also be used as a framework for testing hypotheses on the origin of contamination in the catchment and for identification of unknown contaminant sources.     

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.     

油气集输站安全监控预警及管理信息系统的开发

提出油气集输站安全监控预警及管理信息系统建设的调研内容、需求分析以及安全相关控制系统的风险分析流程。设计了该系统建设的4层结构框架和拓扑图,深入研究了实时参数监控、分级报警与安全保护控制、智能诊断与预警、多媒体监控、安全生产管理信息子系统的主要开发内容和功能实现。     

高墩大跨连续刚构桥施工期安全评价

针对高墩大跨连续刚构桥施工期结构概率失效的特性,提出了基于失效概率的安全评价方法.以徐水沟特大桥为工程背景,通过风险评定识别出施工最不利阶段--最大双悬臂时的主要风险因素即:节段特性模量的不确定性、梁体自重的不确定性以及预应力损失的不确定性.采用大型通用有限元程序ANSYS及蒙特卡洛法,计算徐水沟特大桥在最大悬臂时的失效概率,并确定施工期的目标可靠度.依据高墩大跨连续刚构桥施工期结构概率失效的评价结果,提出相应的风险控制措施.     

基于临水区域化工园区的整体安全研究

针对临水区域化工园区的生产特点及在整体安全方面存在的普遍问题,提出在临水区域化工园区内要进行合理布局,做到功能分区明确;同时需建立园区安全生产管理、监测预警及应急处置系统,主要是由固定危险源和移动危险源动态安全管理子系统、安全生产监测预警系统、突发事故应急处置平台等所组成;坚持安全监控信息化与标准化,对化工园区的整体安全性的提高将发挥巨大的作用,为建设"平安园区"打下坚实的基础。     

三维脚型测量技术及方法的研究

本文阐述了人体脚型的测量方法及特点,比较后得出人工测量与三维扫描测量技术之间的差别。以YETI三维脚型扫描仪为模型,详细分析了脚型扫描仪的结构原理,摸索并提出了简单实用的测量方法,讨论了YETI三维脚型扫描仪获得的原始数据、脚型横截面以及脚型投影图的特点。