Natural radiation exposure in the Campo Arañuelo region in the surroundings of Almaraz nuclear power station (Spain)

During 1998 regional surveys were conducted to evaluate natural radiation exposure of people in the vicinity of the six Spanish nuclear power stations. Indoor radon, external gamma dose rates outdoors and indoors and radioactivity in soil were measured in these surveys. The highest mean annual effective dose to the population was found in the surroundings of the Almaraz nuclear power plant in the province of Cáceres and was mainly due to the presence of high radon concentrations in homes. In order to make a more accurate assessment of the dose coming from the radon in this area, a new and more extensive surgery on indoor radon with a total of 380 measurements was carried out in 2000 in the Campo Ara?uelo region around the Almaraz nuclear power station. From the results obtained in this survey, a population-weighted mean annual effective dose from radon exposure of 1.7 mSv y(-1), 44% lower than that previously reported in 1998, was estimated for the whole Campo Ara?uelo region. The maximum dose value due to radon exposure, about 4 mSv y(-1), was reached in the so-called La Vera area located in the north of this region. The relationship between the indoor radon concentrates experimentally measured, the geological characteristics of this geographic area and the information provided by the radiation map of the Spanish MARNA Project is also analyzed, confirming that La Vera area should be considered as a high radon level area.     

Arsenic geochemistry and health

Arsenic occurs naturally in the earth's crust and is widely distributed in the environment. Natural mineralization and activities of microorganisms enhance arsenic mobilization in the environment but human intervention has exacerbated arsenic contamination. Although arsenic is useful for industrial, agricultural, medicinal and other purposes, it exerts a toxic effect in a variety of organisms, including humans. Arsenic exposure may not only affect and disable organs of the body, especially the skin, but may also interfere with the proper functioning of the immune system. This paper, therefore, generally highlights the toxic effects of arsenic as well as its mobilization in the natural environment and possible controls. It also briefly attempts to outline the impact of arsenic on the immune system, whose alteration could lead to viral/bacterial infections.     

Fire risk reduction through a community‐based risk assessment: reflections from Makola Market,Accra, Ghana

This paper explores the level of vulnerability to the hazard of fire that exists in Makola Market in Accra, Ghana, and assesses how this threat can be reduced through a community‐based risk assessment. It examines the perceptions of both market‐stall occupants and primary stakeholders regarding the hazard of fire, and analyses the availability of local assets (coping strategies) with which to address the challenge. Through an evaluation of past instances of fire, as well as in‐depth key stakeholder interviews, field visits, and observations, the study produces a detailed hazard map of the market. It goes on to recommend that policymakers consider short‐to‐long‐term interventions to reduce the degree of risk. By foregrounding the essence of holistic and integrated planning, the paper calls for the incorporation of disaster mitigation measures in the overall urban planning process and for the strict enforcement of relevant building and fire safety codes by responsible public agencies.     

Benefits of integrating complementarity into priority threat management

Conservation decision tools based on cost‐effectiveness analysis are used to assess threat management strategies for improving species persistence. These approaches rank alternative strategies by their benefit to cost ratio but may fail to identify the optimal sets of strategies to implement under limited budgets because they do not account for redundancies. We devised a multiobjective optimization approach in which the complementarity principle is applied to identify the sets of threat management strategies that protect the most species for any budget. We used our approach to prioritize threat management strategies for 53 species of conservation concern in the Pilbara, Australia. We followed a structured elicitation approach to collect information on the benefits and costs of implementing 17 different conservation strategies during a 3‐day workshop with 49 stakeholders and experts in the biodiversity, conservation, and management of the Pilbara. We compared the performance of our complementarity priority threat management approach with a current cost‐effectiveness ranking approach. A complementary set of 3 strategies: domestic herbivore management, fire management and research, and sanctuaries provided all species with >50% chance of persistence for $4.7 million/year over 20 years. Achieving the same result cost almost twice as much ($9.71 million/year) when strategies were selected by their cost‐effectiveness ranks alone. Our results show that complementarity of management benefits has the potential to double the impact of priority threat management approaches.     

Enzymatische Umsetzung von Arsenkampfstoffen durch das Pilzenzym Mangan-Peroxidase

Degradation of organo-arsenical chemical warfare agents by fungal enzyme manganese peroxidase. The fungal enzyme manganese peroxidase was used to degrade different organo-arsenical chemical warfare agents in cell-free reaction mixtures (in vitro). The decrease in the concentration of arsenical chemical warfare agents was determined by gas chromatography after derivatization with thiols. All organo-arsenical compounds tested were converted by room temperature for more than 90%. Aliphatic arsenical compounds were attacked more rapidly than aromatic derivatives.     

Achieving environmental standards with stochastic discharges

The inherent stochastic nature of the levels and composition of environmental waste discharges are well known to environmental control agencies, who recognize that realistically environmental quality constraints must be formulated in probabilistic terms. Given the specification of environmental constraints in such terms, it is shown that the set of activity vectors which satisfy the constraint will, in general, be nonconvex. This militates against the determination of an efficient solution. A means of avoiding the potentially high computational and informational costs associated with the determination of an efficient solution in such cases is proposed.