伴生矿开发利用辐射环境管理机制探讨

伴生矿开发利用引起的天然放射性水平升高正受到国内外的广泛关注。通过介绍和分析我国伴生矿辐射环境管理的现状及其存在的问题,认为问题的制度成因主要是监管职责不明确、资金保证制度和废物处置导则的缺失,在此基础上提出以监管机构为主导,开发废物处置示范工程和建立资金保证制度等政策建议,以推进我国伴生矿辐射环境管理的有效实施。     

Needle stick and sharps injuries among health care workers in Gondar city, Ethiopia

Background

All employees in health care settings handling needles or other sharps are at risk for needle stick and sharps injuries (NSSIs). Health care workers in under developed countries are at greater risk of infection from blood borne pathogens because of the lack of safety devices and the high prevalence of these pathogens.

Objectives

The aim of this study was to assess the prevalence of NSSIs and associated factors among health care workers in government health institutions in Gondar city, Ethiopia.

Methods

Institution based cross sectional study was conducted from May-December, 2010. The study included 344 health care workers who were selected from the source population using simple random sampling technique. Data were collected through interviews using structured and pre-tested questionnaire and the collected data were entered and analyzed using SPSS version 16.0.

Results

The prevalence of NSSIs among health care workers in the preceding 12 months was 106 (30.8%), of which 58 (54.7%) was reported by females. Lack of training on occupational health and safety, working more than 48 h/week, dissatisfaction with work environment and work culture, greater than 10 years of work experience and having low and moderate perception of risk were found to be significantly associated with NSSIs.

Conclusion

The study found high prevalence of NSSIs among health care workers. Effective training, ongoing awareness on the risk of hazards, preventive measures such as engineering control, and post-exposure prophylaxis following NSSIs are essential to reduce the risk of such injuries.     

水质总氮测定中影响因素分析

通过大量水质中总氮的测定实践，总结出蒸馏水纯度、加热氧化时间、试剂纯度及储存时间、波长的准确定位以及实验室环境等因素均会对测定结果的准确性产生影响。对以上影响因素进行逐一分析和实验对比，提出改进建议，以减少分析误差提高测试准确性。     

Assessment of elemental contaminants in water and fish samples from Aba river

The elemental contaminants in water and fish samples from Aba river were studied. The elements studied were Zn, Ni, As, Hg, Co and Mn. Three water samples and three samples of different fish species were collected from different locations in the river. The water and fish samples were analysed for elemental contaminants using Atomic Absorption Spectrophotometer (AAS). The elemental toxicants Zn and Mn were identified in appreciable amounts in fresh fish species namely, Lates niloticus and Oriochronis niloticus, of mean values 8.012 ppm and 0.861 ppm, respectively. The analysis also shows arsenic concentration of mean value 0.01 ppm in Lates niloticus. The analysis of frozen fish samples purchased from the Waterside market located near the river shows Ni and Hg levels of mean values 0.83 ppm and 0.02 ppm, respectively. The levels of elemental contaminants As, Zn, Hg and Mn from the water samples have mean values 0.082 ppm, 11.284 ppm, 0.201 ppm and 1.024 ppm, respectively. There are five industries that discharge waste products into Aba river. In view of this, there is a need to determine the level of pollution of the river, since the inhabitants depend on the river for their drinking water, fishing and other domestic uses. This study is aimed at determining the level of heavy metal toxicants in fish and water samples from the river. The effect of these elemental contaminants and the associated health hazards were examined.     

无公害蔬菜基地规划建设中的几个环境问题探讨

无公害蔬菜生产是农业产业结构调整的重要内容,也是农民增收的重要途径。在无公害蔬菜基地的规划建设中要充分考虑土壤、大气、水源等方面的环境因素,以确保产品的安全性。基地的规划建设要尽可能远离城市和污染较重的工厂区域,要与公路保持一定的距离,基地附近要有清洁的水源,不得使用城市污水直接灌溉,城市污泥作为有机肥施用要首先进行无害化处理。     

青岛市机动车排放源强与排放量研究

阐述了青岛市城市机动车的发展现状和道路交通状况,采集典型交通状况的车流量和车速数据,对评价区域进行了移动线源、面源的源强分析计算,得到了该区域内机动车排放网格数据,通过修正的排放因子计算了青岛市机动车主要尾气污染物的年排放量,目的是为机动车污染治理提供了理论数据。研究表明从排放源源强分析机动车道路污染状况和污染区域分布,不受扩散模式的影响,可以简单有效的评价机动车排放污染程度;青岛市城市主干道以成为机动车污染物的主要排放源,针对青岛市机动车尾气污染情况提出了合理的污染物治理建议。     

Removal of dicofol from water by immobilized cellulase and its reaction kinetics

Researches on the removal of dicofol catalyzed by immobilized cellulase were conducted. Factors, such as acidity, temperature, enzyme activity, and initial concentration of dicofol, which could influence the removal were studied. The optimal pH for dicofol removal by immobilized cellulase was approximately 4–7, broader than that for free enzymes. The removal efficiencies for immobilized and free cellulase both decreased with increasing initial concentration of dicofol. The K_m for immobilized cellulase was slightly lower than that of free cellulase, suggesting that substrate affinity may be enhanced by immobilization. The optimum temperatures for immobilized and free cellulase were 45 °C and 50 °C. The removal reaction for immobilized cellulase was found to be a first-order reaction. The activation energy was 64.3 kJ mol⁻¹. The continuous oxidation of dicofol carried out in the static system of immobilized cellulase showed that the removal efficiency of immobilized cellulase remained after six cycles of operation. Thus, the catalytic efficiency of cellulase was improved greatly. As evidenced by infrared and gas chromatography–mass spectrometry data, the mechanism of reaction might involve an attack by the OH free radical of cellulase at a weak location of the dicofol molecule, resulting in the removal of three chlorine atoms from dicofol, thus oxygenizing dicofol and producing 4,4′-dichloro-dibenzophenone.     

A critical discussion of research on the social acceptance of renewable energy generation and associated infrastructures and an agenda for the future

Social sciences’ research on the social acceptance of renewable energy generation and associated technologies (RET), such as high voltage power lines, has been growing in the last decades. In fact, while RET are considered one of the main mitigation measures of climate change, opposition to their construction, and namely from the local communities living nearby, is often found. Important conceptual proposals have been made for a better understanding of opposition, however, this literature still presents some limitations. Here, I will discuss two of them: first, the main focus on the local and, with it, the lack of a relational and critical approach, which recognizes opposition and other types of responses to RET as public participation in RET-related issues; second, the focus on the individual and the consequent lack of examining people’s material practices and engagements.     

港口起尘影响因素分析及粉尘污染控制措施与建议

介绍了港口粉尘污染类型,港口粉尘污染包括静态污染和动态污染,容易产生粉尘污染的常见固体散货码头有煤炭码头、矿石码头和水泥码头等,对煤炭、矿石等固体散货码头的起尘影响因素进行了分析,不同货物的种类和粒径、含水率、风力及储存方式等均对港口起尘产生影响,从码头和堆场装卸过程、港口物料输送过程、堆场和港区内道路等角度分别介绍了粉尘污染控制措施,对前沿的防尘方式,如防风网和筒仓的抑尘机理及在国内外的应用情况进行了介绍,并从港口选址、平面布置、管理、监测和科研等角度对港口污染防治提出建议。