A laboratory study of the persistence of carbofuran and its 3‐hydroxy‐ and 3 keto‐metabolites in sterile and natural mineral and organic soils

Abstract

In a laboratory study, the persistence of carbofuran and its 3‐hydroxy‐ and 3‐keto‐metabolites was examined separately over 16 wk in sterile and natural organic (muck) and mineral (loam) soils. Carbofuran was relatively persistent in sterile soils; at 8 wk 77% remained in the sterile muck and about 50% remained in the sterile loam. In the natural muck 25% of initial carbofuran remained at 8 wk whereas in the natural loam carbofuran had completely disappeared by that time. The 3‐ketocarbofuran was very short‐lived even in the sterile muck where only 50% remained at 1 wk. The 3‐hydroxycarbofuran degraded appreciably on zero day in the natural soils (with conversion to 3‐ketocarbofuran) and about 90% had disappeared in 1 wk. A more detailed study of the persistence of 3‐hydroxycarbofuran in the natural soils showed complete disappearance in 2 days in loam and in 3 days in muck. The 3‐ketocarbofuran produced from the 3‐hydroxy‐carbofuran reached a maximum concentration in 1 day and then disappeared within 4 days in loam and about 1 wk in muck.     

基于直觉模糊距离法的堰塞湖减灾方案选优

针对堰塞湖减灾群决策信息的不确定性与模糊性,为解决不完全信息条件下属性指标及专家之间存在的相互关联群决策问题,综合运用直觉模糊集理论、海明距离原理和熵权理论,将直觉模糊距离群决策方法运用到堰塞湖减灾决策过程中。工程实例研究表明,运用直觉模糊距离法决策出的最优方案具有较高的区分度和敏感性,增强了决策的客观性、科学性,能为堰塞湖减灾决策提供更为可靠的依据,具有较强的实用价值。     

Ignition characteristics, conditions of criticality and disappearance of criticality of cumene hydroperoxide reaction by modeling approach

The thermal explosion problem of cumene hydroperoxide exothermic reaction which is used in chemical industries for production of some chemical materials is investigated. The analytical solutions of the problem to determine the margin between ignition and non-ignition systems are presented. The solution offers different analytical expressions which relate between the critical parameters for both steady and unsteady-states in different planes of solutions for different cases. The numerical solutions in different planes offer different trajectories of solution as sub-critical (non-ignition) and supercritical (ignition). Also from the numerical solution the relations between the critical parameters are presented. The critical behaviors from both analytical and numerical solutions are concise and pertained the same results.     

Wireless alerts for extreme weather and the impact on hazard mitigating behavior

Wireless alerts delivered through mobile phones are a recent innovation in regulatory efforts toward preparation for extreme weather events including flash floods. In this article, we use difference-in-differences models of the number of car accidents from days with government issued alerts for flash flood events in Virginia. We find that wireless alert messages for flash flood warnings reduced car accidents by 15.9% relative to the counterfactual with non-wireless alert protocols. We also use a regression discontinuity model to analyze hourly traffic volume data immediately before and after a flash flood warning message is issued. We find that traffic volume is reduced by 3.1% immediately following the issuance of a wireless alert relative to before the alert. These results imply that wireless alert messages effectively reduce exposure to hazards associated with extreme weather.     

Analytical methods and validation for determining trace elements in red wines

The objective of this work is to quantify As, Hg, Cd, Ni and Pb in Portuguese red wines. First, the methods for the quantification of trace elements in red wines were validated. Several pre-treatments were compared, namely a pre-digestion process with HNO₃, a pre-oxidation step with H₂O₂, and a spiking step of wine samples with a known concentration of the trace elements analyzed. Except for As, it was determined that the quantification of the trace elements does not require a pre-digestion process with HNO₃. For all of the trace elements analyzed, a pre-oxidation step with H₂O₂ may enable an accurate quantification. The techniques chosen for the quantification of trace elements were hydride generation atomic absorption spectrometry (HGAAS) for As and Hg, electrothermal atomic absorption spectrometry (ETAAS) for Cd, and flame atomic absorption spectrometry (FAAS) for Ni and Pb. In the second stage of this work, 25 Portuguese red wines spanning all of the red wine-producing regions were analyzed for all of the five trace elements referred to above. Only Cd and Pb have shown concentrations above the limit values defined by the “Organization Internationale de la Vigne et du Vin.” The Target Hazard Quotient (THQ) equation was used to determine in which wine-producing regions that wine consumption can be a problem for public health in terms of the concentrations of the five trace elements analyzed. THQ values have indicated that for the universe of the 25 red wines analyzed no region produces wines that can pose problems for public health, when the Portuguese red wine standard consumption is considered.     

Risk assessment for human consumption of perfluorinated compound-contaminated freshwater and marine fish from Hong Kong and Xiamen

Perfluorinated compounds (PFCs) are man-made fluoro-surfactants that are identified as global pollutants and can pose health risks to humans and wildlife. Two aspects of risk assessment were conducted in this study, including exposure and response. Exposure was estimated by using the concentrations of PFCs in fish and applying standard exposure factors. Among different PFCs, PFOS, PFOA, PFNA, PFDA, PFUdA and PFTrDA were detected. Total concentrations of PFC in fish ranged from 0.27-8.4 ng g⁻¹ to 0.37-8.7 ng g⁻¹ respectively in Hong Kong and Xiamen. The calculated hazard ratio (HR) of PFOS for all fish was less than 1.0. However, the HR for mandarin fish in Hong Kong and bighead carp, grass carp and tilapia in Xiamen, had HR values of approximately 0.5, indicating that frequent consumption of these 4 more contaminated fish species might pose an unacceptable risk to human health. Our data support the notion that the released/disposed chemical pollutants into water systems make fish a source of environmental toxicants to humans. The risks and potential effects of PFCs to health of coastal population in the Pearl River Delta are of concern.     

某铁路隧道作业场所职业危害风险控制效果评价

为了解铁路隧道作业场所职业病危害特征,评估其职业病危害风险控制效果,采用现场调查与职业病危害因素检测相结合的方法,对某铁路隧道作业场所职业病危害特征进行调查,采用职业病危害风险指数评估模型进行控制效果评估。结果表明,该铁路隧道作业场所职业危害因素主要包括生产过程中职业病危害、劳动过程中危害和生产环境中危害;主要职业病危害因素为电焊烟尘、矽尘、NO、NO2、CO、CO2、噪声、振动、高湿等;隧道内工务、电务、供电三大线路作业场所的线路维护人员接触的噪声均为轻中度危害,氮氧化物(NO、NO2)为轻度危害,接触的CO为中高度危害,线路维护人员矽尘作业岗位为轻中高度危害,易导致职业病损的发生。提出应重点监控该铁路隧道接触噪声、CO和矽尘的作业岗位,采取科学综合防控措施,改善作业环境质量,强化个人防护。     

Hazard mitigation or mitigation hazard?

BACKGROUND, AIM AND SCOPE: Transgenic oilseed rape (Brassica napus L.; OSR) is estimated to be environmentally and economically problematic because volunteers and ferals occur frequently and because of its hybridisation potential with several wild and weedy species. A proposed mitigation strategy aims to reduce survival, in particular in conventional OSR crops, by coupling the transgenic target modification with a dwarfing gene to reduce competitive fitness. Our study allowed us to access potential ecological implications of this strategy. MATERIALS AND METHODS: On a large scale (>500 km(2)), we recorded phenological and population parameters of oilseed rape plants for several years in rural and urban areas of Northern Germany (Bremen and surroundings). The characterising parameter were analysed for differences between wild and cultivated plants. RESULTS: In rural areas, occurrences of feral and volunteer OSR together had an average density of 1.19 populations per square kilometre, in contrast to urban areas where we found 1.68 feral populations per square kilometre on average. Throughout the survey, the vegetation cover at the locations with feral OSR ranged from less than 10% to 100%. Our investigations gave clear empirical evidence that feral OSR was, on average, at least 41% smaller than cultivated OSR, independent of phenological state after onset of flowering. DISCUSSION: The findings can be interpreted as phenotypic adaptation of feral OSR plants. Therefore, it must be asked whether dwarfing could be interpreted as an improvement of pre-adaptation to feral environments. In most of the sites where feral plants occurred, germination and establishment were in locations with disturbed vegetation cover, allowing initial growth without competition. Unless feral establishment of genetically modified dwarfed traits are specifically studied, it would not be safe to assume that the mitigation strategy of dwarfing also reduces dispersal in feral environments. CONCLUSIONS AND RECOMMENDATIONS: With respect to OSR, we argue that the proposed mitigation approach could increase escape and persistence of transgene varieties rather than reducing them. We conclude that the development of effective hazard mitigation measures in the risk evaluation of genetically modified organisms requires thorough theoretical and empirical ecological analyses rather than assumptions about abstract fitness categories that apply only in parts of the environment where the plant can occur.     

模糊评判模型在边坡稳定性评价中的应用

本文以澜沧江中下游流域边坡稳定性评价为实例，为模型评判模型的应用问题和处理技术进行了论述。认为该模型简便实用、效果稳健、适应性强，是边坡稳定性评价工作中适宜推广的一个实用模型。此外，文中还提出了用于模型评判模型的信息检验法，讨论了这一方法在遴选有效评价因子和优化模型效能中的作用。     

Effect of objective risk on key actor support for seismic mitigation policy

This article investigates the policy formulation process related to seismic hazard mitigation. A preemergent policy climate is identified by focusing on key actors, assessments of seismic risk, and policy alternatives. Two major factors were found to affect key actor support for policy development: (a) the objective risk to which their constituent community is exposed, and (b) their elective or appointive position at the local level of government.