Hybridization between wheat (Triticum aestivum) and the wild species Aegilops geniculata and A. biuncialis under experimental field conditions

Hybridization between Aegilops geniculata, A. biuncialis and bread wheat Triticum aestivum has been evaluated during two seasons under simulated field conditions to estimate the field hybridization rate under Central Spain conditions. The mean frequencies of hybridization between A. biuncialis and A. geniculata with wheat were 0.34% and 0.31%, respectively. Data from 10 hybrid plants for each combination showed that hybrids can be partially fertile by backcrossing with wheat parent, with percent averages of 3.17 grains/spikelets for A. biuncialis × wheat hybrids and 2.87 grains/spikelets for A. geniculata × wheat hybrids. Self-pollination, although at very low rates, was also possible in hybrids. The potential risks associated with natural hybridization in the context of transgenic wheat cultivation are discussed.     

Toxic metals in sewage sludge-amended soils: has promotion of beneficial use discounted the risks?

Land application of contaminated waste products has been defended as beneficial use by some scientists and regulators, based on the premise that the behavior of any toxins accumulated in soils from this practice is reasonably well understood and will not have detrimental agronomic or environmental impacts into the foreseeable future. In this review, I use the case of toxic metals in sewage sludges applied to agricultural land to illustrate that metal behavior in soils and plant uptake is difficult to generalize because it is strongly dependent on the nature of the metal, sludge, soil properties and crop. Nevertheless, permitted agricultural loadings of toxic metals from sewage sludges are typically regulated using the sole criterion of total metal loading or concentrations in soils. Several critical generalizing assumptions about the behavior of sludge-borne metals in soil-crop systems, built into the US EPA risk assessment for metals, have tended to underestimate risks and are shown not to be well justified by published research. It is argued that, in the absence of a basic understanding of metal behavior in each specific situation, a more precautionary approach to toxic metal additions to soils is warranted.     

土壤重金属污染及其预防、修复研究

土壤重金属污染是一个难以解决的全球性棘手问题,不仅会直接或间接地危害人体健康,而且其污染的修复也十分困难,因此土壤重金属污染的预防与修复具有特别重要的意义.目前中国部分地区土壤重金属污染已相当严重,土壤污染防治已被提上中国环境保护工作的重要议程.文章先从自然地理环境的整体性出发说明土壤重金属污染的危害,接着介绍了由于人类活动引起的农耕区及城市土壤重金属污染来源,最后有针对性地提出土壤重金属污染的预防及其修复措施.     

Prevention of debris flow disasters on Chengdu-Kunming Railway

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Integrated environmental assessment and pollution prevention in Vietnam: the case of anthracite production

Using the concept of life cycle analysis, the whole life cycle of anthracite production in Vietnam was assessed and the environmental “hot-spots” were identified. These include (i) dust pollution at coal transfer points or piles in storage; (ii) noise pollution resulting from the usage of heavy equipment, and (iii) high volume of acid and turbid mine water discharged into the environment.Pollution prevention and treatment options were identified and discussed in this study which consists of wet treatment of dust, planning, collection and treatment of mine water, planting of trees for dust and noise reduction as well as minimization of erosion. Some recommendations are made for pollution abatement from coal production and improvement of anthracite production in the region.     

城市垃圾污染防治对策探讨

从城市拉圾产生的机制入手，分析了城市垃圾污染产生的原因，并对目前所采取的主要处理方法人季简要评述，在此基础提出了实现城市垃圾最小量化，推动垃圾资源化产业、提高垃圾无害化处理水平，中化监督管理等几点城市垃圾污染防治的对策。     

中国清洁生产的立法问题

清洁生产的立法需要突出针对性和循序渐进的原则。根据工艺技术的先进性和行业发展状况的不同，其法律规范分为四亿层次：禁止性规范，提倡性规范，鼓励性规范和强制性规范。灵活性和可操作性是清洁生产立法的特点。     

Fisheries management: integrating societal preference, decision analysis, and ecological risk assessment

Fisheries management is the practice of analyzing and selecting options to maintain or alter the structure, dynamics, and interaction of habitat, aquatic biota, and man to achieve human goals and objectives. The theory of fisheries management is: managers or decision makers attempt to maximize renewable `output' from an aquatic resource by choosing from among a set of decision options and applying a set of actions that generate an array of outputs. Outputs may be defined as a tangible catch, a fishing experience, an existence value, or anything else produced or supported by renewable aquatic resources. Overall output is always a mix of tangible and intangible elements. However defined, management goals and objectives are essential components of fisheries management or any other field of renewable natural resource management. Reaching consensus on management goals and objectives has never been a simple task. Beyond the broad and often conflicting goals of an agency, managers must decide who should set specific management objectives — agency personnel, the public, or a combination of the two. Historically, rhetoric aside, fisheries managers in North America nearly always have consulted with professionals in governmental roles to set management objectives. In a strongly pluralistic society, this often resulted in protracted political and legal conflict. Increasingly, there are calls for use of risk assessment to help solve such ecological policy and management problems commonly encountered in fisheries management. The basic concepts of ecological risk assessment may be simple, but the jargon and details are not. Risk assessment (and similar analytical tools) is a concept that has evoked strong reactions whenever it has been used. In spite of the difficulties of defining problems and setting management objectives for complex ecological policy questions, use of risk assessment to help solve ecological problems is widely supported. Ecological risk assessment will be most useful (and objective) in political deliberations when the policy debate revolves around largely technical concerns. To the extent that risk assessment forces policy debate and disagreement toward fundamental differences rather than superficial ones, it will be useful in decision making.     

室内主要污染物甲醛防治对策研究

保护环境,消除空气污染早已成为人类可持续发展的重要举措.随着经济的高速发展,人们的生活水平也不断提高.但人们在追求生活环境和工作环境质量的同时,也带来了一系列的室内污染问题,从而引起了人们越来越多的关注.其中甲醛是一种对人体健康十分有害的物质.本文主要针对室内污染中最常见的污染物甲醛的特性、来源以及对人体健康的危害进行了认真分析,结合实际工作中的经验与学习室内污染的防治知识,并在此基础上提出了几项比较实用的防治对策.     

地球环境中的放射性污染

地球环境中的放射性污染有天然辐射来源和人为放射性来源,通过消化道、呼吸道和皮肤、粘膜或伤口进入人体内,对人体形成直接损伤、间接损伤和远期辐射效应,应从内照射和外照射防护两个方面来防止环境中的放射性污染.