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Effective management of the risks posed by lead depends on an understanding of the relationship between exposure (the presence and accessibility of lead in the environment) and dose (blood lead levels). Our paper begins by outlining the type of information most valuable to a decision maker addressing the lead problem. A useful exposure-dose characterisation must address multiple contamination sources simultaneously, provide estimates of the number of people with blood lead levels exceeding critical thresholds, and assess the influence of modifying factors (e.g. the soil and dust ingestion rate) on population blood lead variability. We describe a pilot effort to develop an urban setting lead exposure-dose model, and use this model to compare three approaches for generating model input quantities: (1) worst-case estimates, (2) central estimates and (3) Monte Carlo simulation. Using the criteria outlined above, we find that the Monte Carlo technique provides the most useful model output. We describe the population blood lead level distribution generated by the model, as well as the relative influence of environmental and behavioural factors on the variability of the population distribution. Finally, we assess the impact of parameter uncertainty on the model output, and contend this type of information can help identify areas in which further empirical study would be most valuable.  相似文献   
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Accurate and timely flood inundation maps serve as crucial information for hydrologists, first‐responders, and decision makers of natural disaster management agencies. In this study, two modeling approaches are applied to estimate the inundation area for a large flooding event that occurred in May 2016 in the Brazos River: (1) Height Above the Nearest Drainage combined with National Hydrograph Dataset Plus (NHDPlus‐HAND) and (2) International River Interface Cooperative — Flow and Sediment Transport with Morphological Evolution of Channels (iRIC‐FaSTMECH). The inundation extents simulated from these two modeling approaches are then compared against the observed inundation extents derived from a Landsat 8 satellite image. The simulated results from NHDPlus‐HAND and iRIC‐FaSTMECH show 56% and 70% of overlaps with the observed flood extents, respectively. A modified version of the NHDPlus‐HAND model, considering networked catchment behaviors, is also tested with an improved fitness of 67%. This study suggests that NHDPlus‐HAND has the potential for real‐time continental inundation forecast due to its low computational cost and ease to couple with the National Water Model. Better performance of NHDPlus‐HAND can be achieved by considering the inter‐catchment flows during extreme riverine flood events. Overall, this study presents a comprehensive examination made of remote sensing compared with HAND‐based inundation mapping in a region of complex topography.  相似文献   
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Mainstreaming represents an integrated, cross government agency approach to incorporating an issue into programmes and policies. Mainstreaming of resource efficiency and sustainable consumption and production (SCP and RE) has been identified to be essential to ensuring the development of policies, programmes, actions and initiatives with a wider reaching set of outcomes than if these were to be undertaken on their own. This paper outlines a guidance framework which was developed to support practitioners, champions and UN support teams on mainstreaming of SCP and RE. The framework is based on the programmatic approach to environmental mainstreaming which has been developed through wide-ranging experience on other environment and poverty-environment related topics. The approach presented here is not linear, and each of the elements requires ongoing evaluation and updating. In addition, it is identified that mainstreaming of SCP and RE should form part of overall environmental mainstreaming efforts. Furthermore, unless a country has already developed a national SCP programme, the development of such a programme and the mainstreaming process discussed in this current document should be done in parallel, not as separate processes.  相似文献   
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Abstract

Scientific and regulatory interest in ground water contamination by pesticides increased significantly in 1979. This was prompted by findings of the nematicide 1,2‐dibromo‐3‐chloropropane (DBCP) and the nematicide/insecticide aldicarb (Temik®) in ground water in several states. Since that time, at least 130 pesticides and pesticide metabolites have been detected in ground water in over 150 studies, but detection frequencies are 4–10% nationally. Detection frequencies of pesticides over Health Advisory Levels are generally lower. Screening‐level models and detailed computer simulation models are useful for risk assessments and regulatory decisions. Attenuation Factor, CMLS, PRZM2, GLEAMS, and LEACHM are all useful models.  相似文献   
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The 1992 Earth Summit highlighted the critical role of consumption in affluent nations as a source of global environmental deterioration. While most developed countries have begun over the past decade to grapple with the difficult challenges of reducing household demand for energy and materials, sustainable consumption has yet to attract substantive attention in the United States. There exist, however, several strategic openings that American proponents of more environmentally benign household provisioning could exploit to launch a public dialogue about the environmental implications of contemporary consumption. First, public health professionals have in recent years begun to make significant strides publicizing the nutritional inadequacy of the American diet and the contributory role it plays in elevating incidences of chronic disease. Second, the rapid increase in the rate of obesity in the country is now coming to be understood as a health problem that is attributable to the prevalence of sedentary lifestyles. Finally, there is growing public concern in the United States over the accumulation of unprecedented levels of consumer debt and the epidemic of personal bankruptcies. The intent of this paper is to highlight the need to consider the personal dimensions of everyday life when formulating strategies to foster more sustainable consumption.  相似文献   
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Shortened fetal long bones (SFLB) are usually indicative of a skeletal dysplasia. Our aim in this observational retrospective study was to describe a new association between SFLB, small for gestational age (SGA) fetuses and placental abnormalities, and to suggest an aetiologic explanation. During the last decade we have evaluated nine cases in which SFLB (more than 2SD below the mean) was associated with SGA, abnormal maternal serum placental hormones and abnormal placental sonography. Six cases had significantly increased second trimester maternal serum βhCG and four developed toxaemia of pregnancy or had chronic hypertension. On histology, mature placentas with vascular abnormalities, including chorangiosis, large infarcts and slightly increased syncytial knots were noted. The combination of SFLB, SGA fetuses and placental abnormalities (sonographic, as well as histological) suggested a possible common pathway in the aetiology of this association. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   
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