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1.
Life-span studies, using the laboratory mouse, are an efficient means for determining potential chronic toxicity of various materials. However, difficulties that affect the analysis of the data include (1) incomplete and missing observations due to canabilism or autolysis, (b) possible differences in overall mortality rate between treated and control populations that preclude assessments based upon observed final incidence, and (c) potential interaction between specific pathological states. Being aware of these difficulties does not eliminate their consequence, but careful attention to ascertaining the presence or absence of a disease state coupled with an assessment of its significance for each individual can allow greater confidence to be placed in data obtained from survival studies. The question of possible interaction between disease states is better approached experimentally by judicious use of serial killing to define age-specific disease prevalence.Many diseases are difficult to identify in animals as small as the mouse. At the other extreme, too much importance may be attributed to some disease states, not because of their lethality, but because of their ease of detection. One way to minimize the uncertainties introduced by conscious and unconscious observational bias is to adhere to a highly systematic tissue examination of every animal, regardless of condition of apparent cause of death. Through application of well-defined and stable diagnostic criteria a better appreciation can be obtained of the full spectrum of lethal and incidental pathologies observed in animals dying throughout the survival study.  相似文献   

2.
Close to three billion people globally and over 800 million in India are dependent on direct combustion of unprocessed solid biomass fuels in inefficient traditional mud stoves. Current cooking practices, besides causing serious health problems, are also being linked to emissions of climate change and pollution agents such as black carbon and ozone precursors. In India several initiatives have been taken up to tackle the problem but the present trajectory of limited technical and social change in cooking energy use is nonetheless persistent in rural areas. In order to develop and scale up alternative cooking technology options, we have analyzed, using the principles of strategic niche management, two projects implemented by The Energy and Resources Institute (TERI) in nine villages in India. The assessment, while highlighting reasons for stability of the current cooking regime, also points to triggers that can destabilize the regime. The focus is also on assessing the influence of protection in the form of subsidies on the process of transition. User preferences relating to social and technical aspects have been analyzed, pointing to forced draft cookstoves as the preferred option notwithstanding cost reductions to address affordability concerns. The assessment indicates that while it is critically important to understand and address the preferences of users and to improve the technology, scaling up will depend on stove cost reduction through further research. Creativity in effective financing schemes and support structures put in place by fostering public–private partnerships are also needed.  相似文献   

3.
It has been well demonstrated that polycyclic aromatic hydrocarbons (PAHs) can cause reproductive toxicity, and shorter telomere length in sperm may be one of the factors causing male infertility. However, whether exposure to PAHs is associated with sperm telomere length (STL) has never been evaluated. The present study aimed to assess the potential association between PAHs exposure and STL, and to explore potential biomarkers that may predict the effects of low-level exposure to PAHs on human sperm. Questionnaires and biological samples were collected from 666 volunteers participating in the Male Reproductive Health in Chongqing College Students (MARHCS) cohort study in 2014. Semen parameters were measured for 656 participants, while urinary PAH metabolites, STL and sperm apoptosis were successfully measured for 492, 444 and 628 participants, respectively. The linear regression analysis revealed that increased levels of urinary 1-hydroxypyrene (1-OHPyr) and 1-hydroxynapthalene (1-OHNap) were associated with decreased STL (− 0.385; 95% CI, − 0.749, − 0.021 for 1-OHPyr; and − 0.079; 95% CI, − 0.146, − 0.011 for 1-OHNap). The significant negative associations remained after adjusting for potential confounders. However, no significant associations were observed between urinary PAH metabolites and semen quality or sperm apoptosis. We also administrated rats with benzo[a]pyrene (B[a]P; 0, 1, 5, and 10 mg/kg) for 4 weeks and found shorter STL and decreased telomerase expression in germ cells in a dose-dependent manner. In conclusion, environmental exposure to some PAHs may be associated with decreased human STL, and the in vivo animal results also demonstrate the adverse effects of B[a]P on telomere of male germ cells.  相似文献   

4.
With a changing climate and increased urbanisation, the occurrence and the impact of flooding is expected to increase significantly. Floods can bring pathogens into homes and cause lingering damp and microbial growth in buildings, with the level of growth and persistence dependent on the volume and chemical and biological content of the flood water, the properties of the contaminating microbes, and the surrounding environmental conditions, including the restoration time and methods, the heat and moisture transport properties of the envelope design, and the ability of the construction material to sustain the microbial growth. The public health risk will depend on the interaction of these complex processes and the vulnerability and susceptibility of occupants in the affected areas. After the 2007 floods in the UK, the Pitt review noted that there is lack of relevant scientific evidence and consistency with regard to the management and treatment of flooded homes, which not only put the local population at risk but also caused unnecessary delays in the restoration effort. Understanding the drying behaviour of flooded buildings in the UK building stock under different scenarios, and the ability of microbial contaminants to grow, persist, and produce toxins within these buildings can help inform recovery efforts. To contribute to future flood management, this paper proposes the use of building simulations and biological models to predict the risk of microbial contamination in typical UK buildings. We review the state of the art with regard to biological contamination following flooding, relevant building simulation, simulation-linked microbial modelling, and current practical considerations in flood remediation. Using the city of London as an example, a methodology is proposed that uses GIS as a platform to integrate drying models and microbial risk models with the local building stock and flood models. The integrated tool will help local governments, health authorities, insurance companies and residents to better understand, prepare for and manage a large-scale flood in urban environments.  相似文献   

5.
Rapidly developing countries like India face numerous challenges related to social and environmental sustainability, which are associated with their fast economic growth and rising energy demand, climate change, and widening disparities between the rich and the poor. Recently, a number of claims have been made in the literature that the prospects of alternative development pathways in emerging economies in Asia are becoming more likely, and that these economies might even leapfrog Western initiatives. This paper contributes by reporting on the five most visible and established initiatives in the area of off-grid PV solar energy in India, specifically homing in on the innovative business models that are evolving. We develop a new typology of upscaling dimensions in order to analyze these five initiatives. They are found to be quite successful, but have difficulty in terms of reaching the poorest of the poor (deep upscaling) and bringing about required institutional change (institutional upscaling).  相似文献   

6.
Forest fires represent a serious threat to public security in Europe due to the large burned area. Moreover, smoke pollution due to forest fire events is an important public health issue for the communities directly affected, and particularly for the personnel involved in firefighting operations. Aiming to contribute to the scientific knowledge concerning firefighters exposure to forest fires smoke, data of individual exposure to carbon monoxide, nitrogen dioxide, volatile organic compounds, and particulate matter were obtained during experimental field fires for a group of 10 firefighters equipped with portable “in continuum” measuring devices. Measured values are very high exceeding the Occupational Exposure Standard limits, in particular for peak limit thresholds. These are the first measurements and analysis of firefighter's individual exposure to toxic gases and particles in fire smoke experiments in Europe. However, they already indicate that urgent measures to avoid these levels of exposure are needed.  相似文献   

7.
Quantitative information on the adsorption/desorption of radionuclides by suspended loads is important in the study of their environmental behavior. In this paper, controlled laboratory experiments were directed at studying the kinetic transfer and final distribution of radiostrontium in aqueous suspensions using 85Sr as tracer. The results showed that the uptake of 85Sr in seawater can be properly described by one reversible-reaction model. However, in the absence of competitive cations, it has been shown that two reactions of different characteristic times are unambiguously involved in the kinetic evolution of adsorption. Thus, a modeling approach consisting of three-box model has been applied. The model predicts in a satisfactory way the time evolution of activities in the dissolved phase and two sites in the particles. Experimental evidence showed, through comparison among kinetic and distribution coefficients corresponding to different conditions, that Ca2+ affects strongly the rate and extent of Sr uptake by suspended particles. On the other hand, distribution coefficients were found to be sensitive to changes in suspended particulate matter (SPM) concentration, exhibiting a reverse effect with this parameter on the adsorption. In addition, desorption from particles is important showing that Sr can be easily released due to cation-exchange processes.  相似文献   

8.
Radon gas occurs naturally in the environment with variable distribution, concentrating sufficiently in the built environment in some areas to pose a public health risk. Radon levels can be successfully reduced in affected buildings, and large-scale remediation programmes have been justified in terms of accrued costs and benefits. We present results from a house where radon levels in the main living-room and master bedroom were monitored on an hourly basis over extended periods before and after radon remediation by sub-slab depressurisation. These results were combined with results from a recent occupancy survey to estimate the health impact on occupants spending varying times in the home. Prior to remediation, mean hourly radon exposure is moderately linearly correlated (R(2)=0.66-0.78) with time spent in the house. Following remediation, correlation is significantly enhanced (R(2)=0.91-0.95), but the exposure reduction of an occupant following remediation is less than that predicted using the NRPB protocol.  相似文献   

9.
10.
运用比较分析法指出江苏省在第三产业高度发展的同时主要存在的资源环境问题。在对资源环境问题的特点及原因分析的基础上以餐饮业为例进行进一步说明,最终提高人们对第三产业资源环境问题的重视。  相似文献   

11.
Despite the often mentioned environmental benefits associated with transition from fossil fuels to renewable energy sources, their use for electricity production has non-negligible negative environmental impacts. The most commonly mentioned in surveys concern different types of landscape impacts, impacts on the fauna and flora, and noise. These impacts differ by size and location of plants, and by source of energy, rendering the policy decision complex. In addition, there are other welfare issues to take into consideration, as positive and negative environmental impacts are not evenly distributed among population groups. This paper proposes to compare the welfare impacts of renewable energy sources controlling for the type of renewable as well as the specific environmental impact by source. To this end, two discrete-choice experiments are designed and applied to a national sample of the Portuguese population. In one case, only individual negative impacts of renewables are used, and in another case, the negative impacts interact with a specific source. Results show the robustness of discrete-choice experiments as a method to estimate the welfare change induced by the impacts of renewable energy sources. Overall, respondents are willing to pay to reduce the environmental impacts, thus making compensation for local impacts feasible. Moreover, the estimations reveal that respondents are significantly sensitive to the detrimental environmental effects of specific renewable energy sources, being willing to pay more to use these sources of energy relative to others.  相似文献   

12.
Religion in its most ideal form is seen as a powerful force to create ecological transformations to succeeding generations that share similar religious beliefs. This provides an interesting argument for enhancing their role in sustainability transitions. Malaysia is a relevant geographical context in this regard since almost all of its citizens formally embrace some kind of religious belief. However, such ideas are discussed mostly at the theoretical level with little systematic empirical investigation. This paper aims to fill this gap by presenting theoretically informed empirical insights on how a number of religious communities are currently creating successful experiments in recycling within the context of an urban community in Malaysia. The paper argues that such evidence may demonstrate the ‘potential’ role of religious communities to provide localised resources for recycling experiments that can be advantageous for the transition towards a more sustainable municipal solid waste management in Malaysia. The empirical basis of this paper is based on an exploratory multiple case study of successful recycling programmes conducted by selected religious communities from four key religions in Malaysia—Buddhism, Christianity, Hinduism and Islam. The theoretical framework for this research is based on the sustainability transitions literature, particularly the ‘transition experiment’ framework.  相似文献   

13.
对西方环境移民研究中几个基本问题的认识   总被引:2,自引:0,他引:2  
随着全球环境问题的加剧,环境移民问题正日益受到世界各国政府和国际社会的高度重视.由于环境移民问题的复杂性,学术界和政界对环境移民问题一直存在着争议.一些人认为环境移民起因复杂,环境因素只是众多原因之一,因此否认环境移民的存在,另一些人认为环境因素可以成为环境移民的诱导和主要原因,因而环境移民在世界各地大量存在.本文对具有争议的有关环境移民的称谓和定义以及分类等问题进行了评述,认为:为便于对环境移民问题的深入研究和有利于相关问题的解决,应尽可能避免使用"环境难民"一词,而统一采用"环境诱发移民"或"环境移民"等术语;考虑到环境移民的诱因、规模和特点,综合已有各种分类方案,可将环境移民分为环境灾害移民、环境退化移民和环境征用移民三大类.中国学者提出的"环境移民"和"生态移民"与西方学者所讨论"环境移民"和"生态移民"在内涵上并非完全一致.应当引起我国学术界的注意.  相似文献   

14.
在武汉疫情管控期间,企业经济活动和机动车活动水平明显大幅下降,大部分污染源基本停止排放,意味着在此期间全国各地区应该出现优良天气,但是事实上在我国部分地区却出现了严重雾霾天气,这种反预期现象引起人们的普遍关注,甚至怀疑我国大气环境治理是否存在失误。根据这种反预期现象,提出环境污染应当是由流量污染和存量污染共同决定的猜想。为验证这一猜想,分别假设了两种情况:第一种只有流量污染,第二种既有流量污染又有存量污染,并用武汉疫情管控前后的实际排放数据模拟得到空气质量状况,寻找雾霾形成的规律,然后与武汉疫情管控前后实际监测数据进行对比,确定反预期现象的原因。实际数据和模拟数据对比发现,实际情况与假设1不符,与假设2相符。据此认为,大气污染是由当期排放的污染与积累的存量污染共同决定。在此基础上,进一步分析存量污染造成的经济损失,分析表明:2007年被低估1.64亿元,到2017年被低估3.83亿元;在消散率为0.05、贴现率为0.01时,流量、存量和流量与存量损失的差额分别为6.5亿元、50.5亿元和44.0亿元,这意味着2007—2017年总的经济损失被低估44.0亿元。在消散率为0.3、贴现率为0.1时,流量、存量和流量与存量损失的差额分别为4.6亿元、10.5亿元和5.9亿元,这意味着2007—2017年总的经济损失被低估5.9亿元。研究发现,长期累积形成的存量污染是一个被忽视的大气污染源,从而解释了在武汉疫情管控期间低水平经济活动条件下仍然会出现重度大气污染的经验事实。其政策含义在于,制定反污染政策需要根据存量污染的特征进一步完善相关政策设计。  相似文献   

15.
In four types of newly built single family dwellings and in apartments of a block of flats in the Netherlands, the behaviour and motivations of the occupants are studied with respect to their response to heating and ventilation, as well as their judgment on indoor air and climate variables such as tobacco smoke, cooking smells, vapour, mould, dryness, draft and temperature. Knowing the behaviour of the occupants and the building characteristics, estimates are made on the air flows through the dwellings and these air flows are related to stated indoor air and climate problems. The results from the field studies provide recommendations for architects and developers of dwellings and installations and to researchers working on this type of field study. A thesis is proposed that people still define something as a problem, if the resolution offered to solve the problem is also experienced as undesirable.  相似文献   

16.
The general methodological approach to the conservation of Earth’s natural biota in a developing civilization based on mineral resources of the lithosphere is substantiated. The principles of interaction between the technosphere and biosphere that ensure their combined development are formulated on the basis of the concept of coevolution of antagonistic systems.  相似文献   

17.
As environmental issues changed its focus from pollution and endangered species to fulfilling basic human needs, such as health, education, shelter, sanitation, hygiene, on the one hand and social justice on the other hand, it widened in its scope. People questioned about adequacy of ecological knowledge in solving daily questions in their life, and also contribution of their values, objective life situations and idea of quality of life for ecological well-being. Two core and complimentary values strongly emerged from the concept of sustainable development; namely environmental protection and justice. Unfortunately, there is lack of awareness on dimensions of human life and its linkages with the wider environment. To combine the values, dimensions of human life and its linkages with external environment, fundamental changes in human behaviour for human development is required. Present article reflects on dimensions of life, essential skills and practical tools for environmental protection and human development.  相似文献   

18.
The Hudson River is contaminated with PCBs and a remedial program has been formulated by New York State in order to cope with this toxic pollutant. Over $3 million has been spent to document fully the extent of the PCB contamination in the Upper Hudson River. It appears that over 60% of the PCBs in the riverbed are contained within 40 so called “hot spot” areas, that is, those areas that have PCB concentrations greater than 50 ppm. After evaluating all alternatives, the PCB Reclamation Project was formulated which consists of mechanically or hydraulically dredging the 40 “hot spot” areas and placing the contaminated sediments in a encapsulated land burial facility. Such a facility would meet all federal and state criteria for PCBs disposal. New York is seeking to finance this remedial project through the use of federal funds, that could be obtained either through, the Clean Water Act or through special Congressional legislation or through the Superfund Bill, once it is enacted. The PCB Reclamation Project, if funded this spring, as is presently anticipated, could be completed ny 1983.  相似文献   

19.
For the first time, zooplankton and environmental factors have been studied in winter in the deep stratified lakes Siverskoe, Borodaevskoe, and Vydogoshch. The zooplankton consists of 18–22 species of rotifers, copepods, and cladocerans, including 15–18 specifically winter, cryophilic and eurythermic forms. The populations of zooplankters reproduce actively: males and egg-bearing females (in copepods), females with embryos and eggs in brood pouches (in cladocerans), and females with attached eggs (in rotifers) are present. In lakes Siverskoe and Borodaevskoe (depth 20–24 m), where oxygen deficiency is observed only in the bottom water layer, the zooplankton populates the greater part of the water column and forms a large aggregation in the oxycline and near the bottom. The abundance of bacteria in these zones is high (up to 4–6 × 106 cells/ml). In Lake Vydogoshch (depth 16 m), oxygen deficiency extends to the middle layers, and all zooplankton is distributed above the oxycline. The biomass of winter zooplankton in Lake Siverskoe in 1983 averaged 1.26 g/m3, with a maximum of 4 g/m3; in 1993, 1.4 and 8.04 g/m2; the respective values in Lake Borodaevskoe were 0.98 and 3.1 in 1983 and 0.14 and 1.6 in 1993; in Lake Vydogoshch, 0.15 and 0.24 in 1983 and 1.25 g/m3 in 1993. The development of winter zooplankton is limited by the size of the zone of oxygen deficiency and depends on the amount of food (bacterioplankton). The distribution of zooplankton in the water column and its biomass in individual layers is determined by the rate of methane formation and oxidation.__________Translated from Ekologiya, No. 3, 2005, pp. 201–214.Original Russian Text Copyright © 2005 by Rivier.  相似文献   

20.
《Environment international》1999,25(6-7):853-860
The ArcInfo Geographical Information System (GIS) was used to develop spatial databases for recording spatial data. The databases developed in this study provide a graphic and mapping display interface to assist the management of the Namoi Basin in New South Wales, Australia. In addition, the databases are used in the investigation of the impacts of spatio-temporal changes in landuse/management on hydrologic processes from catchment to basin scales. Climate, stream flow, and water quality data are being incorporated into the ArcInfo dataset to drive and test hydrologic models.  相似文献   

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