A structured hazard identification method of human error for shale gas fracturing operation

Shale gas fracturing is a complex system of continuous operation. If human errors occur, it will cause a chain reaction, from abnormal events to fracturing accidents, and even lead to abandonment of shale gas wells. The process of shale gas fracturing has many production stages that are complex and the consequence of any error is serious. The human error modes in shale gas fracturing process are mutative. Therefore, human error should be studied in a systematic way, and in a hybrid framework, that is, whole integration of identification, prioritization, reasoning, and control. A new structured identification method of human error in a hybrid framework for shale gas fracturing operation is presented in the article. First, human error is structurally identified based on the human HAZOP method. Second, fuzzy VIKOR method is applied to comprehensive prioritization. Finally, 4M element theory is used to analyze the human error and control its evolution. The method improves the consistency of the identification results through the standard identification step and the identification criterion. Results from a study of feed-flow process indicate that 34 kinds of human errors can be identified, and high-probability errors occur in the behavior of implementation and observation.     

涪陵焦石坝页岩气开采区土地损毁的生态风险评价

页岩气在勘探、开采、集输过程中对周边生态系统会产生直接或间接影响。通过构建页岩气开采土地损毁生态风险因果链识别井场、运输道路及集输管线等风险源,基于最小阻力模型定量分析土地损毁的生态累积影响;选取了植被覆盖度、生态服务价值及土壤肥力等因子表征区域生态重要性,土壤侵蚀度、石漠化敏感性及水环境敏感性等表征生态脆弱性,综合评价区域生态敏感度,并以此为风险受体,实现涪陵焦石坝页岩气开发区的生态风险评价。2012—2015年末,涪陵焦石坝页岩气产建区钻井数量快速增加,分布广,页岩气开发对区域生态累积影响扩大。2015年末,区域一半以上面积为中、高生态风险区(146.56km~2,55.8%),主要分布于南部乌江河谷及北部低山区,前者水环境敏感度高,后者岩溶发育度高,土壤侵蚀度高,石漠化敏感;该区域内大规模页岩气开发将面临水环境污染、生境破坏、土壤退化、石漠化加重及生物多样性减少等生态风险,是生态环境管理及风险防范的重点方面。研究结果可为区域生态安全建设提供科学的参考。     

页岩气开采与深地微生物的相互影响

页岩气是一种特殊的天然气聚集,以吸附或游离状态存在于页岩之中。页岩气资源储量丰富,约占全球天然气能源的三分之一,主要分布在中国、北美、俄罗斯等国家和地区。页岩气开采所使用的水力压裂技术会对深地微生物产生显著影响,在水力压裂的不同阶段,微生物群落组成存在明显差异。其中,产甲烷菌能够提高页岩气的产量,而产酸细菌会造成设备腐蚀,降低页岩气的回收效率。本文概述了页岩气的开采现状、开采过程以及微生物种群的变化和潜在影响,以期促进页岩气开采与深地微生物相互影响的研究,最终推动页岩气的绿色、高效开采。     

Plan for an Integrated Human and Environmental Risk Assessment in the S. Domingos Mine Area (Portugal)

The need for the integration of the assessment of human and ecological risks in contaminated areas, such as derelict mines, widely increases. The risk assessment process is becoming a powerful tool to provide sound scientific bases for decision-making processes. In Portugal, the risk assessment process is in its early years and the lack of multidisciplinary teams of experts is frequently mentioned as the main obstacle to its implementation. Therefore, the majority of the reclamation actions are based on impact assessment studies that usually are characterized by few biological and toxicological considerations. In order to account for some of these constraints, the ecological risk assessment framework proposed by the U.S. Environmental Protection Agency was used to plan the assessment of human and ecological risks posed by the high concentrations of metals scattered in the vicinity of S. Domingos mine, a cuprous pyrite mine located in the Southeast Alentejo (Portugal). This study presents the problem formulation phase of the assessment. It includes all the scientific information available for the area, a conceptual model, and an analysis plan for the risk assessment process. Following a tiered approach, several tasks were planned in order to acquire chemical, toxicological, and ecological information, in order to compensate for the lack of toxicity data for site-specific species.     

Shale gas: a life-cycle perspective for UK production

Purpose

Following the boom of shale gas production in the USA and the decrease in the US gas prices, increasing interest in shale gas is developing in many countries holding shale reserves and exploration is already taking place in some EU countries, including the UK. Any commercial development of shale gas in Europe requires a broad environmental assessment, recognizing the different European conditions and legislations.

Methods

This study focuses on the UK situation and estimates the environmental impacts of shale gas using life-cycle assessment (LCA); the burdens of shale gas production in the UK are compared with the burdens of the current UK natural gas mix. The main focus is on the analysis of water impacts, but a broad range of other impact categories are also considered. A sensitivity analysis is performed on the most environmentally criticized operations in shale gas production, including flowback disposal and emission control, by considering a range of possible process options.

Results and discussion

Improper waste water management and direct disposal or spills of waste water to river can lead to high water and human ecotoxicity. Mining of the sand and withdrawal of the water used in fracking fluids determine the main impacts on water use and degradation. However, the water degradation of the conventional natural gas supply to the UK is shown to be even higher than that of shale gas. For the global warming potential (GWP), the handling methods of the emissions associated with the hydraulic fracturing influence the results only when emissions are vented. Finally, the estimated ultimate recovery of the well has the greatest impact on the results as well as the flowback ratio and flowback disposal method.

Conclusions

This paper provides insights to better understand the future development of shale gas in the UK. Adequate waste water management and emission handling significantly reduce the environmental impacts of shale gas production. Policy makers should consider that shale gas at the same time increases the water consumption and decreases the water degradation when compared with the gas mix supply. Furthermore, the environmental impacts of shale gas should be considered according to the low productivity that force the drilling and exploitation of a high number of wells.

     

Teams in animal societies

We review the existence of teams in animal societies. Teamshave previously been dismissed in all but a tiny minority ofinsect societies. "Team" is a term not generally used in studiesof vertebrates. We propose a new rigorous definition of a teamthat may be applied to both vertebrate and invertebrate societies.We reconsider what it means to work as a team or group andsuggest that there are many more teams in insect societies than previously thought. A team task requires different subtasksto be performed concurrently for successful completion. Thereis a division of labor within a team. Contrary to previousreviews of teams in social insects, we do not constrain teamsto consist of members of different castes and argue that teammembers may be interchangeable. Consequently, we suggest thata team is simply the set of individuals that performs a teamtask. We contrast teams with groups and suggest that a grouptask requires the simultaneous performance and cooperationof two or more individuals for successful completion. In agroup, there is no division of labor—each individual performs the same task. We also contrast vertebrate and invertebrateteams and find that vertebrate teams tend to be associatedwith hunting and are based on individual recognition. Invertebrateteams occur in societies characterized by a great deal of redundancy,and we predict that teams in insect societies are more likelyto be found in large polymorphic ("complex") societies thanin small monomorphic ("simple") societies.     

Ecological and human health risk assessment of agricultural soils based on heavy metals in mining areas of Singhbhum copper belt,India

Risk characterization of agricultural soils in the mining areas of Singhbhum copper belt was done by determining the total concentrations of metals using inductively coupled plasma-mass spectrometry and assessing the potential ecological and human health risks. The concentrations were above the average shale values for most of the metals. Principal component analysis showed anthropogenic contributions of Cu, Ni, Co, Mn, Pb, and Cr in the soils. Ecological risk assessment revealed that 50% of the soil samples were at moderate to very high ecological risk. Health risks for adults and children were calculated using hazard quotients (HQs), hazard index (HI), and Cancer risks for the oral, dermal, and inhalation pathways. The HQs for all the metals except As and Co were below 1, which suggested that non-carcinogenic risks due to metal exposure through soils were within the safe limit. However, considering all the metals and pathways, the HI for adults and children was 0.71 and 5.61, respectively, suggesting appreciable risk to local residents. The carcinogenic risks due to As and Cr in the soils were within the acceptable value of 1E–04. For both carcinogenic and non-carcinogenic risks, oral ingestion appeared to be the primary pathway followed by dermal and inhalation pathways.     

How to make predictions about future infectious disease risks

Formal, quantitative approaches are now widely used to make predictions about the likelihood of an infectious disease outbreak, how the disease will spread, and how to control it. Several well-established methodologies are available, including risk factor analysis, risk modelling and dynamic modelling. Even so, predictive modelling is very much the 'art of the possible', which tends to drive research effort towards some areas and away from others which may be at least as important. Building on the undoubted success of quantitative modelling of the epidemiology and control of human and animal diseases such as AIDS, influenza, foot-and-mouth disease and BSE, attention needs to be paid to developing a more holistic framework that captures the role of the underlying drivers of disease risks, from demography and behaviour to land use and climate change. At the same time, there is still considerable room for improvement in how quantitative analyses and their outputs are communicated to policy makers and other stakeholders. A starting point would be generally accepted guidelines for 'good practice' for the development and the use of predictive models.     

Catastrophe and social order

This paper presents three propositions. First, the author suggests that there is a growing potential for technologically induced catastophes. Second, our capacity to analyze technological risk is inhibited in part because: (1) we tend to confuse low-probability/low-consequence events with low-probability/high-consequence risks; (2) we seldom adopt a holistic approach to the analysis of risk; and (3) we tend to underestimate the effects of catastrophic events. The author further argues that existing control systems, including federal regulatory bodies, are inadequate. In the conclusion the author discusses difficulties likely to accompany the design and creation of risk control systems.     

废气生物处理设施排放的微生物气溶胶逸散特征、影响因素与暴露风险研究进展

生物处理技术因其具有高效、成本低廉、操作简便、清洁、无二次污染等特点,已被广泛应用于废气处理方面,但微生物气溶胶会作为二次污染物从废气处理设施排放到周围空气中。由于携带和传播有害微生物,微生物气溶胶对人体健康造成潜在危害和风险。废气生物处理设施既是微生物气溶胶的“汇”,也是微生物气溶胶的“源”。本文阐述了废气生物处理设施微生物气溶胶的逸散水平、群落结构和粒径分布特征,分析了其形成原因、主要来源、影响因素和暴露风险,为废气生物处理设施产生的微生物气溶胶的识别和控制技术研究提供科学依据和参考。     

基于多风险源胁迫的西南地区生态风险评价

西南地区生态环境复杂、人地矛盾突出,生态系统面临着多种风险胁迫,进行生态风险评价对区域生态风险的预警和防控具有重要的意义。基于西南地区的生态环境特征,将生态风险分为自然灾害风险与人类活动风险,从风险源危险性、生态系统潜在损失度、生态系统易损性3个方面构建单一风险评价模型,将单一风险评价结果进行综合分析得到西南地区综合生态风险结果。研究表明,西南高生态风险区面积为17.02万km2,占研究区总面积7.4%,主要分布在念青唐古拉山、邛崃山、哀牢山、无量山、金沙江、怒江、澜沧江、大渡河流域等地,以及成都、重庆、贵阳等人地作用强烈的大城市周边。这些地区环境复杂,灾害易发,应加强防控与监测,优化产业结构,继续推进生态保护工程,降低生态风险。     

A Food Scare a Day: Why Aren't We Better at Managing Dietary Risk?

Does the existence of food scares mean that we are bad at risk management? Not necessarily. New information brings new risks to the forefront or puts known risks into a new perspective. But in some cases food scares do indicate poor risk management. There are two key problems that explain why we are not better at managing dietary risks. The first is an imbalance of effort among the three components of risk analysis: we have Hummer risk assessment, Yugo risk management, and tricycle risk communication. The second problem is inadequate risk management. The cases of risks from mad cow disease and dioxins illustrate how the quality of risk management is affected by what we do not know well enough, what we know too well, and what we have not tried to find out. Better risk management requires a two-tier approach: (1) generate broad and shallow information on risks, health outcomes, incentives, options, benefits, and costs (Toyota Prius Hybrid risk management to be used everyday) and (2) generate narrow and in-depth information on high priority risks (Hummer risk assessment to be used sparingly).     

Risk Management Model of a Micro-Grid Wind Farm

Micro-grid operation mode, which is the combination of a power grid and distributed generation, is the main way for saving investment, reducing energy consumption, and improving a power system's reliability and flexibility, but it has many risks in the process of implementation. In this article, the micro-grid generation structure of a wind farm was established, a processing flow chart of an intelligent management system was drawn, and a risk management model of a micro-grid wind farm was built from the angle of cost risk, including construction of cost risk and operation cost risk models. The construction cost risk model, grid-connected operation, and isolate-operation cost risk model of a micro-grid wind farm were set up by using a mathematical model that consisted of an objective function and constraint conditions. The accuracy of the model was verified through empirical analysis. This provides a reference and mirror for solving grid-connected wind energy problems and gives an important basis for wind energy risk policy-making, and for avoiding the risks in the process of planning, design, and operation management of a wind farm.     

Probabilistic Risk Assessment of Polycyclic Aromatic Hydrocarbons (PAHs) in Produced Water

The produced water extracted during oil and gas production includes formation water, injected water, small volumes of condensed water, and any chemical added during the oil/water separation process. Produced water contains both organic and inorganic constituents, and several studies have been conducted in the past to assess their risk. The toxicity and persistence of polycyclic aromatic hydrocarbons (PAHs) in produced water is of particular environmental concern, but there are very few studies on human health risk assessment from PAHs of produced water. This article summarizes the results of a conservative human health risk assessment approach for PAHs in produced water discharges to the marine environment. Due to the absence of available toxicity data for PAHs, the cancer slope factors were determined by using the relative potency factors (RPF) and Toxicity Equivalency Factors (TEF). Using the concentration distribution factors, the maximum cancer risks to humans were predicted in the range of 4.07 × 10^?7 to 2.95 × 10^?6. The 95th-percentile values show that the risks are well within the acceptable limits.     

利益相关主体医疗风险分担机制的探讨

随着科技的快速发展和信息的扁平化,人类社会的各种风险在不断扩大,个体承担风险的程度是有限的,利益相关主体的合理化分担是保证风险化解的基础。医学作为一门不精确的科学,接近真理和无法穷尽真理是客观事实,作为探索医学真理的利益相关主体的患者、医疗工作者、医院和政府,单一分担医疗风险是不合理的,只有按照相关的规则共同分担,才能保证医学科学的进步和发展。     

美国、加拿大环境和健康风险管理方法

对目前美国和加拿大多个部门使用的风险评价与风险管理方法进行了全面回顾和综合分析,论述各种不同方法的特征,深入探讨各种管理方法的基础、利弊、使用经验,辨识环境、人类健康和职业健康风险综合方法中应该包含的要素,阐述风险管理目标的确定方法,以期为中国的环境风险管理提供经验。     

基于信息网络模型的生态风险评价

人类开发活动造成剧烈的生态系统自然条件变化,生态风险评价可以对受到人为干扰下生态系统(包括物种和群落等)的潜在影响进行模拟和量化。通过对信息流量的概念和网络控制分析,综合考虑生态系统组分间的直接和间接作用,提出一种能实现全局风险模拟的生态网络模型,即信息网络模型。在该模型基础上,建立了面向整体生态系统的生态风险评价框架,同时实现兼容多胁迫因子统一模拟和多风险受体间的风险追踪。以澜沧江漫湾水库为例,在估算重金属Hg、Pb和Cd初始环境风险后,利用信息网络模型追踪分析生态系统中不同生态功能组分之间的风险传递路径,评估各生态组分和整体系统的危险程度。结果表明,在累积效应作用下,对于生态系统和部分群落,整合网络风险值与初始环境风险值之间有着显著差别;在发生环境胁迫时,虽然处于食物网底层的生物类群可能最先受险,但在控制信息作用下食物网上层类群也会受险,甚至其最终受到的潜在威胁比前者更大。信息网络模型可识别出复杂的风险流动路径和群落间的风险累积,从而为生态系统风险评价和管理提供更为系统综合的理论依据。     

What risks should be permissible in controlled human infection model studies?

Controlled human infection model (CHIM) studies involve the intentional exposure of healthy research volunteers to infectious agents. These studies contribute to knowledge about the cause or development of disease and to the advancement of vaccine research. But they also raise ethical questions about the kinds of risks that should be permissible and whether limits should be imposed on research risks in CHIM studies. Two possible risk thresholds have been considered for CHIM studies. The first suggests constraining ethically permissible risks according to a minimal risk threshold and the second endorses a higher risk threshold that excludes irreversible or fatal infections. I argue that neither of these thresholds is persuasive and situate questions about risk thresholds in CHIM studies within a broader debate about permissible risks in research. I argue that risks in CHIM studies should be constrained according to limits on research risks that do not offer corresponding benefits in all studies rather than developing a unique risk threshold for CHIM studies. I then propose five recommendations for the ethical assessment of risk in CHIM studies.     

A Comparative Screening-Level Ecological and Human Health Risk Assessment for Dredged Material Management Alternatives in New York/New Jersey Harbor

Managers of New York and New Jersey Harbor dredging projects are developing strategies to dispose and manage the large volumes of sediment that must be dredged to maintain passable waterways. The various management alternatives include aquatic containment facilities, upland containment, and treatment with beneficial reuse. An important consideration in the selection of an appropriate alternative is the evaluation of potential risks to ecological and human receptors. This study presents a framework for a screening-level ecological and human health risk assessment that compares risks associated with management alternatives for contaminated dredged materials. The major objectives of the work were to identify exposure routes that show the potential for risk and develop a framework that can be used to compare relative potential risks among eight management alternatives. Managers can use this framework to: ? identify characteristics of the placement/treatment alternatives that contribute to potential risk, ? choose one alternative over another for sediments with high concentrations of contaminants, ? implement controls that mitigate risk, or ? identify the need for a more comprehensive site-specific risk assessment.     

水生动物进口风险评估综述

随着全球水产养殖业的发展,水产动物活体或水产品贸易日益频繁,不可避免地给进口国带来病原风险,造成疾病引入和传播,甚至生物入侵,严重危害水产养殖业的发展。水生动物进口风险评估(IRA),是指从别国或地区进口水生动物活体包括其受精卵、稚鱼、幼鱼、苗种、成体以及商品等的风险分析。风险分析是指对风险事件进行科学、透明、系统分析的一个过程,它由危害识别、风险评估、风险交流和风险管理4个部分构成。目前,常用的风险评估方法有定性风险评估、半定量风险评估和定量风险评估3种。定性风险评估具有灵活性强、适用范围广、易掌握的特点,能够综合各种资料、数据和信息,尤其适合初次风险评估,但容易受评估人员主观因素的影响。定量风险评估可避免主观因素的影响,评估结果准确、可靠,但需要收集大量数据,工作量巨大,评估成本也很高。通常,定性评估结果若能够提供很好的防范措施,则不必进行定量评估。将外来水生病原阻止在引进之初远比引入后根除更加容易。因此,开展水生动物进口风险评估对于阻止水生动物疾病传播和水生态环境破坏具有重要意义,同时也可为各国进行水产贸易提供参考。