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981.
In 2010, an estimated 400 to 500 children died of acute lead poisoning associated with artisanal gold mining in Zamfara, Nigeria. Processing of gold ores containing up to 10% lead within residential compounds put residents, especially children, at the highest risk. Principal routes of exposure were incidental ingestion and inhalation of contaminated soil and dusts. Several Nigerian and international health organizations collaborated to reduce lead exposures through environmental remediation and medical treatment. The contribution of contaminated food to total lead exposure was assessed during the environmental health response. Objectives of this investigation were to assess the influence of cultural/dietary habits on lead exposure pathways and estimate the contribution of contaminated food to children's blood lead levels(BLLs). A survey of village dietary practices and staple food lead content was conducted to determine dietary composition, caloric intakes, and lead intake. Potential blood lead increments were estimated using bio-kinetic modeling techniques. Most dietary lead exposure was associated with contamination of staple cereal grains and legumes during post-harvest processing and preparation in contaminated homes. Average post-harvest and processed cereal grain lead levels were 0.32 mg/kg and 0.85 mg/kg dry weight, respectively. Age-specific food lead intake ranged from 7 to 78 μg/day. Lead ingestion and absorption were likely aggravated by the dusty environment, fasting between meals, and nutritional deficiencies. Contamination of staple cereal grains by highly bioavailable pulverized ores could account for as much as 11%–34% of children's BLLs during the epidemic, and were a continuing source after residential soil remediation until stored grain inventories were exhausted.  相似文献   
982.
Equity and efficiency should be considered when allocating resources for climate change adaptation. More than a decade after the Least Developed Countries Fund approved adaptation funds for 18 countries in 2003, it is possible to take the stock of investment data and to test empirically whether equity and efficiency have been factored into adaptation investment decision-making. To evaluate equity, one must determine if resources were distributed to areas of greatest need. Vulnerability assessments provide information on the global distribution of the need for adaptation. To evaluate efficiency, one must compare cost and benefit of an investment. Although it is difficult to assess ex-ante the cost and benefit of investment strategies, it is possible to measure efficient use of expenditures with readiness assessment, as a metric of capacity to deploy adaptation resources. We used vulnerability and readiness measures of the Notre Dame Global Adaptation Initiative (ND-GAIN) Country Index as proxies of equity and efficiency. This article quantitatively interrogates—through the lens of public fund allocation—the roles of vulnerability and readiness in shaping adaptation investment decisions. Our findings suggest that countries facing increasing impacts from climate change have received more adaptation investments from international sources than countries with less vulnerability. Further, international investments also preferentially flow to countries that are more ready to deploy adaptation resources. Since the most vulnerable countries are likely to be less ready for investment, our findings support the efforts to improve the investment potential of the most vulnerable countries by investing first to enhance their readiness, in order to unlock adaptation solutions.  相似文献   
983.
We applied a multi-isotope approach to examine aspects of niche partitioning, competition, and mobility for rodents in the Central Highlands of Madagascar. Specifically, we used carbon (δ13C), nitrogen (δ15N), and strontium (87Sr/86Sr) isotope ratios in bone to investigate diet and mobility for endemic tufted tail rats (Eliurus spp.), and introduced black rats (Rattus rattus) and house mice (Mus musculus) within and outside a fragment of montane humid forest in the Ambohitantely Special Reserve. There was a clear spatial segregation in trapping success for different species: Eliurus was only in the forest interior and edge, Mus only outside of the fragment in a marsh and park housing complex, and Rattus in all habitats except the housing complex. We find only moderate support for mobility of rodents among habitats. Mus may routinely move between the marsh and housing complex. However, regular movement between the forest edge and interior, or between the forest fragment and surrounding grassland is not supported. Taxa appear to target different foods: Rattus tends to feed at a higher trophic level than Eliurus, and Mus consumes some C4 resources. To date, strontium isotopes have been underutilized in ecological research. Here, we show that they are highly complementary to carbon and nitrogen isotope data. Even in localities with relatively uniform underlying geology, it may be possible to distinguish individuals that regularly forage in different habitats.  相似文献   
984.
Ionic liquids(ILs) are a class of solvents increasingly used as "green chemicals." Widespread applications of ILs have led to concerns about their accidental entry to the environment.ILs have been assessed for some environmental impacts;however,little has been done to characterize their potential impacts on drinking water if ILs accidentally enter surface water.IL cations are often aromatic or alkyl quaternary amines that resemble structures of previously confirmed N-nitrosamine(NA) precursors.Therefore,this study has evaluated two common ILs,1-ethyl-3-methylimidazolium bromide(EMIm Br) and 1-ethyl-1-methylpyrrolidinium bromide(EMPyr Br),for their NA formation potential.Each IL species was reacted with pre-formed monochloramine under various laboratory conditions.The reaction mixtures were extracted using liquid–liquid extraction and analyzed for NAs using high performance liquid chromatography tandem mass spectrometry.At low concentration of IL(250 μmol/L),the yields of NAs(NMEA or NPyr) increased with increasing doses of monochloramine from both IL species.The total NA yield was as high as 2.5 ± 0.3 ng/mg from EMIm Br,and as high as 8.6 ± 0.8 ng/mg from EMPyr Br.At high concentration of IL(5 mmol/L),the NA yield reached a maximum at 2.5 mmol/L NH_2Cl,and then decreased with subsequent increases in the reactant concentrations,demonstrating ILs' solvent effects.This study re-emphasizes the importance of preventing discharge of ILs to water bodies to prevent secondary impacts on drinking water.  相似文献   
985.
This paper examines controversy during the 2001 foot-and-mouth outbreak after mass carcass burial sites were selected at two sites in northeast England, and focuses on shortcomings in public consultation surrounding the carcass disposal policy. The slaughter of six million animals necessitated a national disposal strategy on a hitherto unknown scale. The belated decision to concentrate carcass disposal in a small number of mass burial sites provoked more opposition in the two ex-mining localities selected in the northeast than anywhere else. In both cases local liaison committees were established to manage dialogue between residents and public authorities. We argue that, although seen by the authorities primarily as a vehicle for risk communication and public reassurance, for residents these functioned chiefly as a vehicle for holding public authorities to account. These divergent purposes were overshadowed by the chaotic circumstances in which the early stages of the mass burial policy were implemented, and the way in which the carcass disposal policy was dictated by the operation of the slaughter policy, whose draconian form precluded any but the most cursory public consultation.  相似文献   
986.
987.
ABSTRACT: Irrigated agriculture is one of the most important water-use sectors in terms of total water diversion and consumptive use. For at least the last 25 years, improving irrigation efficiency has been a widely advocated and accepted goal. This paper uses a sample of 16 Bureau of Reclamation irrigation projects to examine the pattern of average irrigation efficiency and change in efficiency over time. In general, the highest average efficiencies are found in the arid Southwest while the lowest are found in the semi-arid to sub-humid Great Plains region. Over the 22-year period of analysis, there has been no observable trend toward improvement in efficiency at any of the projects.  相似文献   
988.
ABSTRACT: A present concern in decision making processes for forest land use is the environmental effects of land use activities on water, air, and the land itself. Criteria for evaluating the magnitude and detriment of environmental impacts are not definite since it is often difficult to isolate a particular activity as the cause of a particular impact. Instead, interactions between various forest practices must be considered along with their integrated impacts. In order to provide an effective decision tool, the College of Forest Resources, University of Washington, is modeling the forest ecosystem of the Snohomish River Basin located in the Cascade Mountains of western Washington. The project consists of a general system model comprised of subsystem models dealing with product conversion processes, forest production processes, recreation supply processes, wildlife and fisheries supply processes, and the interactions of these processes with water and the atmosphere. The system model is interfaced with a computerized multiple player management game which enables land managers, manufacturing managers, and regulation agency personnel to make management decisions and respond to indications of lack of environmental control. Responses of the hydrologic system to various management decisions are simulated by the water subsystem model. The responses being considered include surface flow quantity and water quality. The model emphasizes the monitoring of non-point as well as point source impacts rather than predicting short-term hydrographs. The significance of impacts vary with land use patterns and the goals of the game player. Therefore, the model has flexible resolution and is able to predict hydrologic conditions for both large and small scale. The water subsystem model responds to management decisions by interpreting the effects of management options selected by game players for 40-acre cells within the Basin. The model then determines which streams are immediately affected, defines the watersheds contributing to these streams, and extracts from a resource data bank the information needed to define model parameters. Using these parameters and precipitation inputs, mean flow discharge on a montly and annual basis is calculated for the impactcd sub watersheds as well as 21 major watersheds of the Basin. Water quality responses predicted for these watersheds include suspended sediment concentration, temperature increases due to stream exposure, dissolved oxygen concentrations, the effects of fertilization on nitrogen content, biocide and herbicide effects, and residues from product conversion processes.  相似文献   
989.
A noticeable push toward using agricultural crops for ethanol production and for undertaking research to expand the range of possible biofuels began to dominate discussions of agricultural science and policy in the United States around 2005. This paper proposes two complementary philosophical approaches to examining the philosophical questions that should be posed in connection with this turn of events. One stresses a critique of underlying epistemological commitments in the scientific models being developed to determine the feasibility of various biofuels proposals. The second begins with a broader set of questions about the philosophical goals of agriculture, then queries the place that a turn to biofuels might have within the philosophy of agriculture. Both are portrayed as viable and important. The paper itself is a preliminary stage-setting reflection on the need for these two types of philosophical inquiry.  相似文献   
990.
Today, over-consumption, pollution and resource depletion threaten sustainability. Waste management policies frequently fail to reduce consumption, prevent pollution, conserve resources and foster sustainable products. However, waste policies are changing to focus on lifecycle impacts of products from the cradle to the grave by extending the responsibilities of stakeholders to post-consumer management. Product stewardship and extended producer responsibility are two policies in use, with radically different results when compared for one consumer product, refrigerators. North America has enacted product stewardship policies that fail to require producers to take physical or financial responsibility for recycling or for environmentally sound disposal, so that releases of ozone depleting substances routinely occur, which contribute to the expanding the ozone hole. Conversely, Europe's Waste Electrical and Electronic Equipment (WEEE) Directive requires extended producer responsibility, whereby producers collect and manage their own post-consumer waste products. WEEE has resulted in high recycling rates of greater than 85%, reduced emissions of ozone-depleting substances and other toxins, greener production methods, such as replacing greenhouse gas refrigerants with environmentally friendly hydrocarbons and more reuse of refrigerators in the EU in comparison with North America.  相似文献   
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