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161.
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Maceachern AD Jindal-Snape D Jackson S 《International journal of occupational safety and ergonomics》2011,17(4):329-339
Child protection is an area of police work which has expanded in the last decade, leading to an increase in the number of police officers working in departments which specialise in investigating cases of child abuse. Police officers in this field may be at greater risk of experiencing secondary traumatic stress but there remains a paucity of research in this area of policing. Analogies can be drawn to existing research in policing and with social service workers involved in child protection. The paper finishes off with implications for police forces to ensure safe working environments and appropriate counselling for employees. 相似文献
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Phosphogypsum (PG), a byproduct of phosphate fertilizer manufacturing, is commonly stacked and capped with soil at decommissioning. Shallow (0, 8, 15, and 30 cm) and thick (46 and 91 cm) sandy loam caps on a PG stack near Fort Saskatchewan, Alberta, Canada, were studied in relation to vegetation establishment and hydrologic properties. Plant response was evaluated over two growing seasons for redtop ( L.), slender wheatgrass ( (Link) Malte ex H.F. Lewis), tufted hairgrass ( (L.) P. Beauv.), and sheep fescue ( L.) and for a mix of these grasses with alsike clover ( L.). Water content below the soil-PG interface was monitored with time-domain reflectometry probes, and leachate water quantity and quality at a depth of 30 cm was measured using lysimeters. Vegetation responded positively to all cap depths relative to bare PG, with few significant differences among cap depths. Slender wheatgrass performed best, and tufted hairgrass performed poorly. Soil caps <1 m required by regulation were sufficient for early revegetation. Soil water fluctuated more in shallow than in thick caps, and water content was generally between field capacity and wilting point regardless of cap depth. Water quality was not affected by cap depths ≤30 cm. Leachate volumes at 30 cm from distinct rainfall events were independent of precipitation amount and cap depth. The study period had lower precipitation than normal, yet soil caps were hospitable for plant growth in the first 2 yr of establishment. 相似文献
165.
An important tool in the evaluation of acidification damage to aquatic and terrestrial ecosystems is the critical load (CL), which represents the steady-state level of acidic deposition below which ecological damage would not be expected to occur, according to current scientific understanding. A deposition load intended to be protective of a specified resource condition at a particular point in time is generally called a target load (TL). The CL or TL for protection of aquatic biota is generally based on maintaining surface water acid neutralizing capacity (ANC) at an acceptable level. This study included calibration and application of the watershed model MAGIC (Model of Acidification of Groundwater in Catchments) to estimate the target sulfur (S) deposition load for the protection of aquatic resources at several future points in time in 66 generally acid-sensitive watersheds in the southern Blue Ridge province of North Carolina and two adjoining states. Potential future change in nitrogen leaching is not considered. Estimated TLs for S deposition ranged from zero (ecological objective not attainable by the specified point in time) to values many times greater than current S deposition depending on the selected site, ANC endpoint, and evaluation year. For some sites, one or more of the selected target ANC critical levels (0, 20, 50, 100μeq/L) could not be achieved by the year 2100 even if S deposition was reduced to zero and maintained at that level throughout the simulation. Many of these highly sensitive streams were simulated by the model to have had preindustrial ANC below some of these target values. For other sites, the watershed soils contained sufficiently large buffering capacity that even very high sustained levels of atmospheric S deposition would not reduce stream ANC below common damage thresholds. 相似文献
166.
McKinley DC Ryan MG Birdsey RA Giardina CP Harmon ME Heath LS Houghton RA Jackson RB Morrison JF Murray BC Patakl DE Skog KE 《Ecological applications》2011,21(6):1902-1924
Using forests to mitigate climate change has gained much interest in science and policy discussions. We examine the evidence for carbon benefits, environmental and monetary costs, risks and trade-offs for a variety of activities in three general strategies: (1) land use change to increase forest area (afforestation) and avoid deforestation; (2) carbon management in existing forests; and (3) the use of wood as biomass energy, in place of other building materials, or in wood products for carbon storage. We found that many strategies can increase forest sector carbon mitigation above the current 162-256 Tg C/yr, and that many strategies have co-benefits such as biodiversity, water, and economic opportunities. Each strategy also has trade-offs, risks, and uncertainties including possible leakage, permanence, disturbances, and climate change effects. Because approximately 60% of the carbon lost through deforestation and harvesting from 1700 to 1935 has not yet been recovered and because some strategies store carbon in forest products or use biomass energy, the biological potential for forest sector carbon mitigation is large. Several studies suggest that using these strategies could offset as much as 10-20% of current U.S. fossil fuel emissions. To obtain such large offsets in the United States would require a combination of afforesting up to one-third of cropland or pastureland, using the equivalent of about one-half of the gross annual forest growth for biomass energy, or implementing more intensive management to increase forest growth on one-third of forestland. Such large offsets would require substantial trade-offs, such as lower agricultural production and non-carbon ecosystem services from forests. The effectiveness of activities could be diluted by negative leakage effects and increasing disturbance regimes. Because forest carbon loss contributes to increasing climate risk and because climate change may impede regeneration following disturbance, avoiding deforestation and promoting regeneration after disturbance should receive high priority as policy considerations. Policies to encourage programs or projects that influence forest carbon sequestration and offset fossil fuel emissions should also consider major items such as leakage, the cyclical nature of forest growth and regrowth, and the extensive demand for and movement of forest products globally, and other greenhouse gas effects, such as methane and nitrous oxide emissions, and recognize other environmental benefits of forests, such as biodiversity, nutrient management, and watershed protection. Activities that contribute to helping forests adapt to the effects of climate change, and which also complement forest carbon storage strategies, would be prudent. 相似文献
167.
Richard C Schwing Bradford W Southworth Calvin R Von Buseck Clement J Jackson 《Journal of Environmental Economics and Management》1980,7(1):44-64
This study examines the optimum automotive emission control levels within a marginal benefit-cost framework. We assume that benefits consist of market and nonmarket components. Cost of control is estimated from historical and projected data as published in the literature. The results of the analyses indicate that even with a high estimate of benefits, the economically optimal vehicle emission levels are strikingly less severe than those required by the 1970 Clean Air Act. 相似文献
168.
This paper examines the flow of cadmium through the global economy, with the aim of quantifying emissions of cadmium into the environment as a result of anthropogenic activities. First, a materials balance methodology is presented as the most appropriate means of assessing cadmium emissions from a wide range of anthropogenic sources. This is then applied to the best available data, from a variety of sources, to arrive at estimated flows of cadmium. Results are presented for 10 geo-political world regions and for a range of economic activities including non-ferrous metals production, iron and steel production, combustion of fossil fuels, fertilizer manufacture and use, cement production and the manufacture, use and disposal of cadmium containing products. Initially, this analysis partitions the total flow of cadmium into three major categories: atmospheric emissions, water-borne effluents and solid or bulked waste arisings. the paper then suggests a probable further partition of the initial emissions into different environmental media. 相似文献
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