首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
肖融  楚文海 《环境科学研究》2021,34(6):1328-1337
饮用水水质安全是关乎千家万户的重大民生问题,其中消毒工艺是保障饮用水微生物安全不可或缺的重要措施,然而由消毒剂与前体物反应生成的DBPs(消毒副产物)被发现具有潜在的健康风险,如致癌及引起发育副作用等.随着对饮用水中DBPs的重视程度不断提高,世界上多个国家、地区或组织将DBPs指标纳入标准.为对我国饮用水水质标准中DBPs指标的制定和修订提出可参考的建议,比较了国内外饮用水和再生水饮用回用水质标准中的DBPs指标,包括DBPs种类、对应的浓度限值和监测要求等.结果表明:①我国饮用水水质标准中涵盖的DBPs种类较多,其中地方标准相较于国标而言对DBPs指标的要求更为严格,但较少考虑综合性指标(如总有机卤素)和高毒性含氮DBPs(如卤乙腈);②国外多部饮用水水质标准或准则中包含一些无浓度限值规定但已知具有较高健康风险的DBPs,此举可指导有关部门进一步开展浓度调研和毒性试验,为未来水质标准的制定提供参考依据.研究显示,我国饮用水标准中DBPs指标需要考虑综合性指标的选取与管控以及高风险指标的甄别和筛查,另外还需因地制宜加强地方性标准的建设工作.   相似文献   

2.
Bioaerosols consist of aerosols originated biologically such as metabolites, toxins, or fragments of microorganisms that are present ubiquitously in the environment. International interests in bioaerosols have increased rapidly to broaden the pool of knowledge on their identification,quantification, distribution, and health impacts(e.g., infectious and respiratory diseases,allergies, and cancer). However, risk assessment of bioaerosols based on conventional culture methods has been hampered further by several factors such as:(1) the complexity of microorganisms or derivatives to be investigated;(2) the purpose, techniques, and locations of sampling; and(3) the lack of valid quantitative criteria(e.g., exposure standards and dose/effect relationships). Although exposure to some microbes is considered to be beneficial for health,more research is needed to properly assess their potential health hazards including inter-individual susceptibility, interactions with non-biological agents, and many proven/unproven health effects(e.g., atopy and atopic diseases).  相似文献   

3.
食管癌是一种常见的消化道疾病,在世界许多国家和地区均有发生,其中环境因素是引发地方病食管癌的重要因素。目前,模型被应用于食管癌的研究中,食管癌研究模型主要有食管癌发病率预测模型,食管癌预防模型及食管癌动物模型等。本文主要综述了前人对中国食管癌发病区的土壤、饮用水和食物等环境地球化学因素,以及与食管癌研究相关的土壤模型和食管癌模型的研究进展。  相似文献   

4.
The development of biosensors for analytical purposes has attracted a great deal of attention in recent years. A biosensor is defined as an analytical device consisting of a biological component (e.g., enzyme, antibody, entire cell, DNA) and a physical transducer (e.g., electrode, optical device). Biosensors are mostly designed for routine analysis, such as clinical diagnosis, quality control of food, in-process control of fermentations, and in environmental analysis. Many of these sensors are also suitable for screening purposes in order to find new drugs. Such systems should yield information either about compounds with known bioactivity or about the bioactivity of samples with known or unknown chemical composition. Biosensors intended for the latter purpose are essentially based on whole cells carrying receptors and ion channels at their surfaces. Miniaturization of structures, primarily based on silicon, allows integration of many sensors into arrays, which may be suitable for the screening of natural and chemical products as well as combinatorial libraries. Until now, no commercially available sensors of this kind exist but they are expected in the near future. Different biosensors, based on enzymes, antibodies, cells, artificial membranes and entire animal tissues, which can be used in drug discovery and may lead to efficient screening systems in the future, are described in this review.  相似文献   

5.
Production of biofuels from microalgae   总被引:1,自引:1,他引:0  
The production of biofuels from microalgae, especially biodiesel, has become a topic of great interest in recent years. However, many of the published papers do not consider the question of scale up and the feasibility of the various processes to be operated at the very large scale required if algal biofuels are to make a meaningful contribution to renewable fuels. All the steps in the process must also be very low cost. This paper discusses the unit processes required for algal biofuels production (i.e., growing the algae, harvesting, dewatering, extraction and conversion to biofuel) and their scalability. In many cases, especially in the lipid extraction step, little is known as yet as to the scalability and economic feasibility of the various processes proposed. We also highlight the key engineering and biological issues which must be resolved for the production of biofuels from microalgae to become an economic reality.  相似文献   

6.
The epidemiological implications with respect to climate change and public health (e.g., shifts in disease vectors) are beginning to be acknowledged. Less recognized however, are the potential links between climate, plant biology and public health. In addition to being affected by climate (e.g., temperature determines plant range), carbon dioxide (CO2) represents the raw material needed for photosynthesis and its rapid increase in the atmosphere is expected to stimulate plant growth. While there are a number of means by which plant biology intersects with human health (e.g., plant nutrition), one of the most widely recognized is aerobiology; specifically, the ability of plants to both produce pollen and to serve as a substrate for molds/fungi (e.g., sporulation). The current review represents an initial attempt to coalesce what is known regarding the likely impacts of climate/CO2 on plant pollen/fungal spores and associated allergic disease that are, or could be, specific to the Northeast United States. Although the current results indicate a number of potentially unfavorable effects, we wish to stress that the current data are based on a small number of experiments. Additional data are crucial to both reduce epidemiological uncertainty and to derive a robust set of mitigation / adaptation strategies.  相似文献   

7.
Droughts can have severe negative effects on the environment, society and economy. The drought of 2001–2002 caused severe strain on economic and social activities in western Canada, particularly on rural communities through changes in water resources. This paper examines physical and social vulnerabilities and associated adaptation measures undertaken and the adaptive capacity in communities in the South Saskatchewan River Basin, Canada. Although all of these communities were exposed to the 2001–2002 drought, they had different levels of impacts, resulting in different types of drought adaptation measures, some due to experience with previous droughts and some in response to the 2001–2002 drought. Communities with unreliable water supply were the most vulnerable to these droughts. This vulnerability resulted in historic adaptations being implemented (e.g., Hanna, Alberta) and re-active adaptations (e.g., Cabri, Saskatchewan). It is important to examine the effectiveness of the current adaptive strategies to cope with more extensive and extended drought situations. First Nation communities, such as the Kainai Blood Indian Reserve, have many social and environmental issues but the impacts from the drought were minor. The Reserve had implemented economic changes in the late 1980s to make it less vulnerable to drought but resulted in negative impacts to the Reserve’s social health. It is imperative to determine how vulnerable First Nation communities are and will to improve future adaptive capacity. This paper provides a snap shot view of how Canadian Prairie Communities have adapted to drought and how vulnerable they are to future drought situations.  相似文献   

8.
在对深海中泄漏的油气混合物在海洋环境中的输运过程及行为变化的分析基础上,建立三维深海溢油输移扩散模型。该模型采用拉格朗日积分法模拟溢油在近区的水下浮射扩散过程,应用粒子追踪法模拟油滴在水下远区的对流扩散以及油膜在海面的漂移扩散过程,并考虑了油气分离输移、气体溶解、天然气水合物形成与分解等复杂行为对溢油运动轨迹的影响。应用该模型数值模拟了两个大型深海溢油现场试验,结果显示溢油在水下环境中的时空分布模拟结果与现场监测数据符合较好,表明该模型具有较高的准确性和实用性,能够为深海溢油的防治管理提供理论与技术支持。  相似文献   

9.
宣威地区肺癌发病率居全国首位,并且肺癌与室内燃煤关系密切. 为了解宣威地区室内燃煤排放PM10的微观形貌和粒度特征,使用小流量Minivol采样器,分别于2011年1月、3月和12月对宣威地区6个代表性乡镇的18个农户及对照点——贵州六盘水幸福村2个农户室内、外的PM10进行采样. 采用扫描电子显微镜分析样品的微观形貌,并对颗粒物粒度进行统计分析. 根据微观形貌特征将PM10分为烟尘集合体(链状、蓬松状、密实状)、球形颗粒(燃煤飞灰和焦油球)、矿物颗粒(规则和不规则状)、生物颗粒及超细未知颗粒. 结果表明:宣威地区室内PM10微观形貌差别较大;室、内外PM10的粒度分布在0.1~0.4μm内的颗粒数量所占比例较大,而1μm以上颗粒体积所占比例较大;小粒径颗粒对颗粒物数量贡献较大,而少数大粒径颗粒对体积贡献较大;宣威地区和对照点室内的PM10数量-粒度和体积-粒度分布相似,室外PM10数量-粒度特征相似但体积-粒度分布有所差异. 宣威地区室内的烟尘集合体和球形颗粒分别占颗粒物总数的10.5%和23.6%,高于对照点 (分别为7.7%和11.3%).   相似文献   

10.
Rooftop agriculture (RA) is an innovative form of urban agriculture that takes advantage of unused urban spaces while promoting local food production. However, the implementation of RA projects is limited due to stakeholders’ perceived risks. Such risks should be addressed and minimized in policymaking processes to ensure the sustainable deployment of RA initiatives. This paper evaluates the risks that stakeholders perceive in RA and compares these perceptions with the currently available knowledge, including scientific literature, practices and market trends. Qualitative interviews with 56 stakeholders from Berlin and Barcelona were analyzed for this purpose. The results show that perceived risks can be grouped into five main categories: i) risks associated with urban integration (e.g., conflicts with images of “agriculture”), ii) risks associated with the production system (e.g., gentrification potential), iii) risks associated with food products (e.g., soil-less growing techniques are “unnatural”), iv) environmental risks (e.g., limited organic certification) and v) economic risks (e.g., competition with other rooftop uses). These risks are primarily related to a lack of (scientific) knowledge, insufficient communication and non-integrative policymaking. We offer recommendations for efficient project design and policymaking processes. In particular, demonstration and dissemination activities as well as participatory policymaking can narrow the communication gap between RA developers and citizens.  相似文献   

11.
This paper investigates how the notion of ‘sustainability’ is strategically framed in the context of Dutch infrastructure governance in the Netherlands. By conducting a frame analysis (based on policy documents, websites and semi-structured interviews), the paper discerns six sustainability frames. These frames concern substantive (e.g., more focus on ecology), process (activating new networks) and organizational (e.g., new practices of work) aspects. The paper also illustrates how these sustainability frames relate to the changing institutional context of infrastructure policy and governance more broadly. The paper discusses some of the productive and challenging implications of the dynamics of sustainability in today’s complex and multi-dimensional world of governance.  相似文献   

12.
Adaptation to climate change is a major challenge facing the viticulture sector. Temporally, adaptation strategies and policies have to address potential impacts in both the short- and long term, whereas spatially, place-based and context-specific adaptations are essential. To help inform decision-making on climate change adaptation, this study adopted a bottom-up approach to assess local climate vulnerability and winegrowers’ adaptive processes in two regulated wine-producing areas in the Anjou-Saumur wine growing sub-region, France. The data used for this study were collected through individual semi-structured interviews with 30 winegrowers. With a focus on wine quality, climate-related exposure, and sensitivity were dependent on many contextual factors (e.g., northern geographical position, wine regulatory frameworks, local environmental features) interacting with the regional oceanic climate. Climate and other non-climate-related variables brought about important changes in winegrowers’ management practices, varying in time and space. This ongoing process in decision-making enhanced winegrowers’ adaptive responses, which were primarily reactive (e.g., harvesting, winemaking) or anticipatory (e.g., canopy and soil management) to short-term climate conditions. Winegrowers described changing trends in climate- and grapevine (Vitis) -related variables, with the latter attributed to regional climate changes and evolving management practices. Regarding future climate trends, winegrowers’ displayed great uncertainty, placing the most urgent adaptation priority on short-term strategies, while changing grapevine varieties and using irrigation were identified as last resort strategies. The study concluded by discussing the implications of these findings in the context of climate change adaptation in viticulture.  相似文献   

13.
The reclamation and disinfection of waters impacted by human activities (e.g., wastewater effluent discharges) are of growing interest for various applications but has been associated with the formation of toxic nitrogenous disinfection byproducts (N-DBPs). Monochloramine used as an alternative disinfectant to chlorine can be an additional source of nitrogen in the formation of N-DBPs. Individual toxicity assays have been performed on many DBPs, but few studies have been conducted with complex mixtures such as wastewater effluents. In this work, we compared the cytotoxicity and genotoxicity of wastewater effluent organic matter (EfOM) before and after chloramination. The toxicity of chloraminated EfOM was significantly higher than the toxicity of raw EfOM, and the more hydrophobic fraction (HPO) isolated on XAD-8 resin was more toxic than the fraction isolated on XAD-4 resin. More DBPs were also isolated on the XAD-8 resin. N-DBPs (i.e., haloacetonitriles or haloacetamides) were responsible for the majority of the cytotoxicity estimated from DBP concentrations measured in the XAD-8 and XAD-4 fractions (99.4% and 78.5%, respectively). Measured DBPs accounted for minor proportions of total brominated and chlorinated products, which means that many unknown halogenated compounds were formed and can be responsible for a significant part of the toxicity. Other non-halogenated byproducts (e.g., nitrosamines) may contribute to the toxicity of chloraminated effluents as well.  相似文献   

14.
农田土壤除草剂污染的修复技术研究进展   总被引:1,自引:0,他引:1  
除草剂主要用于保护农作物免受杂草的侵害,是现代农业生产中用量最多的一类农药.然而,随着全球粮食需求的增加,除草剂的用量逐年增大,药效也不断增强,导致除草剂在农田土壤中出现累积、迁移转化和毒害作用等问题.为了降低除草剂给土壤-作物系统带来的生态风险,根据除草剂污染特征和区域农业生产规律研发绿色低碳修复技术,是目前生态环境领域需要关注的问题.基于此,整理了近年来关于农田土壤除草剂污染治理的相关报道,重点分析了修复技术的研究进展和应用案例,并对除草剂修复领域未来的发展动态进行了展望.目前应用于农田除草剂的修复技术主要有基于微生物修复、酶修复和植物修复的生物修复技术,以及基于生物炭基材料的吸附固定技术.其中,生物修复技术的发展相对成熟,已经应用于实际农田除草剂的修复治理工作,并形成了成功的修复案例.为了提升对农田土壤除草剂污染的修复效果,修复技术逐渐从单一模式向物理化学-生物多技术耦合模式发展,以充分发挥多技术集成应用的协同作用.  相似文献   

15.
昆山市水污染控制研究   总被引:1,自引:1,他引:0  
由于城市化进程的不断加速和人口规模的迅速扩张,昆山市区域水污染不断加剧。根据昆山市水污染现状、未来市域人口规模及城市用地情况,采用分项定额法对昆山市污水量及水污染负荷进行了预测,水污染负荷预测结果及昆山市水域的敏感性表明昆山市已无力承受将来尾水的总负荷。针对这种情况,论文提出了系统集成的“三级控制,三级标准”区域水污染控制模式,提出了从源头控制、污水处理厂建设到尾水导流的全过程水污染控制对策。  相似文献   

16.
The brown mussel Perna perna (Linnaeus, 1758) is a valuable resource for aquaculture in tropical and subtropical coastal regions. It presents desirable characteristics for biomonitoring, including being sessile, widely distributed and abundant, and is a filter-feeder able to accumulate several classes of pollutants (e.g., metals, hydrocarbons, among others). Mussels’ biological responses to pollution exposure can be measured as biomarkers, which include alterations ranging from molecular to physiological levels, to estimate the degree of environmental contamination and its effects on biota. This full review compiles two decades (2000–2020) of literature concerning biological effects on P. perna mussel caused by environmental pollutants (i.e., metals, hydrocarbons, and emerging pollutants), considering environmental and farm-based biomonitoring. Biochemical markers related to mussels’ oxidative status were efficient for the biomonitoring of metals (i.e., antioxidant enzymes associated with oxidative damage in biomolecules). Genotoxicity and cytotoxicity indicators (i.e., comet, micronucleus, and neutral red assays) provided a depiction of hydrocarbon contamination. The neutral red assay gave a time-concentration cytotoxic response to a wide range of pollutants, including emerging pollutants (e.g., pharmaceuticals and biocides) and hydrocarbons. Perna perna hemocyte parameters provided a useful approach for biocide biomonitoring. This paper summarizes useful biomarkers from molecular to physiological levels in this mussel species used to identify and quantify the degree of coastal pollution. An integrated biomarker analysis may provide a way to overcome possible biomarker variations and assess multi-polluted sites. Nevertheless, it is necessary to investigate biomarker variations according to natural factors (e.g., season and gonad maturation stage) to standardize them for trustworthy biomonitoring.  相似文献   

17.
Municipal wastewater discharge is considered as one of the main sources of N-nitrosamine precursors which can impact the qualities of downstream source waters and reclaimed wastewaters for potable reuse. NNitrosamine precursors can be removed to various degrees during biological wastewater treatment (e.g., the activated sludge (AS) process). So far, little is known about the impact of the AS process on N-nitrosamine formation under practical disinfection condition (e.g., uniform formation condition (UFC)). In this study, N-nitrosamine UFC from selected model compounds, sewage components (i.e., blackwaters and greywaters) and sewage samples were comprehensively investigated during batch AS treatment tests. NNitrosodimethylamine (NDMA) formation from the tested precursor compounds (i.e., trimethylamine (TMA) and sumatriptan (SMTR)) under UFC chloramination decreased mostly after 6 or 24 hr treatment with different types of AS (i.e., domestic rural AS, domestic urban AS, and textile AS), and the reductions in NDMA UFC were comparable to their NDMA formation potential (FP) reductions. In urine and feces blackwaters, NDMA UFC increased after 6 or 24 hr treatment with the domestic (i.e., rural and urban) AS, while NDMA FP decreased substantially. The increases in NDMA UFC after AS treatment was presumably attributed to the removal of bulk organic matters (e.g., dissolved organic carbon (DOC)) which favored NDMA formation under UFC. On the other hand, in laundry greywaters having relatively abundant DOC, N-nitrosamine UFC was less affected by DOC removal before or after AS treatment, but decreased to similar degrees with N-nitrosamine FP. In sewage samples collected from wastewater treatment plants, N-nitrosamines UFC tended to increase or remain constant during AS treatment, despite the decreases in their FPs. These results suggest that biological wastewater treatment (e.g., the AS process) may not effectively reduce N-nitrosamine formation (e.g., measured under UFC) partially because the concurrent removal of bulk organic matters (e.g., DOC) favored N-nitrosamine formation in s econdary effluents.  相似文献   

18.
Natural forest re-growth reflects a decline in traditional agricultural practices that can be observed worldwide. Over the last few decades, natural forest re-growth has replaced much of the agricultural land in the Swiss mountains. This is a region where forms of traditional cultivation have preserved unique landscapes and habitats of high ecological value. This study aimed to characterise the locations in the Swiss mountains where agricultural land has been abandoned and overgrown by trees and bushes. Therefore, multivariate statistical models based on geo-physical and socio-economic variables were developed. Land-use change data were taken from two nationwide land-use surveys carried out in the 1980s and 1990s. In order to obtain reliable models, neighbourhood effects and the group structure in our data were accounted for. For the latter a robust estimation technique known as cluster-adjustment was used.Results show that forest re-growth is largely restricted to former alpine pastures, land with grass and scrub vegetation and agricultural land with groups of trees at mid to high altitudes, steep slopes, stony ground and a low temperature sum. Some relationships were not as expected, e.g. many of the new forest areas were found to be relatively close to roads. A new finding from this study was that forest re-growth is largely restricted to regions with immigration, higher proportions of part-time farms as opposed to full-time farms and high farm abandonment rates. By accounting for neighbourhood effects, the model fit was improved. The considerable residual deviance of the models was interpreted as the result of undetected local characteristics, such as poor water availability, small-scaled topographic peculiarities (e.g. small trenches, stonewalls, soil damages by cattle) and the individual's motivation to abandon or maintain cultivation. The conclusion made was that general policy measures for the whole mountain area are not suitable for the prevention of land abandonment and forest re-growth, and that policy measures must pay more attention to local characteristics and needs.  相似文献   

19.
An adult man contains roughly 4-5 g of iron. Nearly 70% of this amount is present in hemoglobin and myoglobin. About 11% is accounted for by iron enzymes, e.g., heme enzymes that play a decisive role in cellular metabolism. Almost 19% of the body iron are deposed in iron stores. The distribution of iron in the body to the tissues and organs is handled by transferrin, a protein that binds iron so tightly that scarcely any free, i.e., ionized and hence toxic iron can exist. Since iron can only be excreted to an insignificant extent either in the urine or bile, the metabolism of iron is balanced almost exclusively by the absorption of this metal from food. This is especially true in the case of iron deficiency, e.g., in the young and growing organism, in pregnant females, or after iron loss.  相似文献   

20.
Nucleic acid hybridization techniques (e.g., Southern blotting and in situ hybridization) gain increasing importance in laboratory medicine, as demonstrated by examples in this paper. The molecular basis of this approach to detect nucleic acids homologous to known DNA probes is explained. It is concluded that this technique has advantages in the detection of pathogens compared to other methods used in laboratory medicine.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号