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 78 毫秒
1.
为准确评估多环芳烃(PAHs)污染土壤对人体的健康风险,解决目前基于总量风险评估导致土壤PAHs修复目标值过严的问题,采用德国标准研究院颁布的生物可给性测试方式研究了石家庄某焦化厂土壤中苯并[b]荧蒽(BBF)、苯并[k]荧蒽(BKF)、苯并[a]芘(BAP)、茚并[1,2,3-cd]芘(IPY)和二苯并[a,h]蒽(...  相似文献   

2.
北京地区表层土壤中多环芳烃的分布特征及污染源分析   总被引:6,自引:0,他引:6  
根据北京地区不同环境功能区62个样品的分析结果,讨论了研究区表层土壤中多环芳烃的分布特征及污染源类型。结果表明:(1)研究区表层土壤中检测到的多环芳烃主要包括萘、苊、菲、惹烯、三芴、荧蒽、芘、、苯并蒽、苯并[b]荧蒽、苯并[k]荧蒽、苯并[e]芘、苯并[a]芘、苝、二苯并[a,h]蒽、茚并[1,2,3–cd]芘、苯并[g,h,i]苝及其同系物;(2)不同环境功能区表层土壤中多环芳烃的组成及质量分数均存在一定的差别,16种优先控制的多环芳烃质量分数为175.1~10 344 ng.g-1,其中城市中心区表层土壤中多环芳烃的质量分数最高,交通干线附近、工矿企业附近表层土壤中PAHs的质量分数较高,林地、果园和农田表层土壤中PAHs的质量分数较低;(3)表层土壤中PAHs既有来源于石油源,也有来源于化石燃料燃烧产物的,但不同功能区二者贡献存在差别,其中农业用地(林地、果园、农田)中PAHs主要来源于石油源(或部分来源于土壤母岩中的有机质),城区、交通干线附近及工矿企业附近表层土壤中PAHs污染源以化石燃料燃烧产物输入为主。  相似文献   

3.
钢铁工业区周边农业土壤中多环芳烃(PAHs)残留及评价   总被引:2,自引:0,他引:2  
对某大型矿业企业周边农业土壤中多环芳烃(PAHs)残留量进行了调查。结果表明,PAHs总残留量范围为312. 2~27 580. 9ng·g-1,且以4环以上多环芳烃组分为主。所有土样中均检出PAHs,单一污染物以芘、艹屈、荧蒽、苯并[a]芘、蒽、菲、苯并[a]蒽、苯并[k]荧蒽、茚并[1,2,3 cd]芘、苯并[g,h,i]苝为主。PAHs残留量与有机质含量相关性较好。不同样区土壤PAHs残留量受常年风向影响明显。以加拿大农业区域土壤PAHs的治理标准值为指标,用内梅罗综合指数法进行评价表明,研究区农业土壤达重污染水平的占37%,中度污染的占19%,轻污染的占25%,另有13%的采样点污染程度处于警戒限,仅有6%的采样点尚处于安全级。  相似文献   

4.
2013年12月在呼和浩特市主城区9个环境空气监测点位同步采集PM_(10)样品,对PM_(10)浓度和16种多环芳烃的浓度、污染特征进行了分析,使用特征比值和主成分分析对多环芳烃来源进行了解析.9个监测点位的PM_(10)浓度介于23.5—322μg·m-3之间,16种多环芳烃总量介于5.34—850 ng·m-3之间.荧蒽、芘、苯并[a]蒽、、苯并[b]荧蒽、苯并[a]芘、苯并[g,h,i]苝和茚并[1,2,3-cd]芘等多环芳烃单体浓度较高,这8种多环芳烃占多环芳烃总浓度的80.4%.主成分分析所获得污染源结果和特征比值法定性判断出的污染源结果一致,燃烧源、机动车尾气源和石油源为主要污染源,分别贡献61.3%、16.0%和10.4%.  相似文献   

5.
采集我国某大型钢铁企业22个表层土壤(0—20 cm)样品,采用气相色谱-质谱(GC-MS)分析了其中16种多环芳烃(PAHs)的含量,并采用荷兰、加拿大土壤标准及苯并[a]芘的毒性当量浓度(TEQBa P)对PAHs生态风险进行评价.结果表明,土壤中∑16PAHs含量范围为21.0—20062.0μg·kg~(-1),平均值为2564.7μg·kg~(-1),单体以Flu、Pyr的含量最高,较之背景点土壤中PAHs含量,平均富集系数为22.9(Bk F)—304.0(Flu).与国内同类研究相比,该钢铁厂表层土壤中PAHs污染处于中等水平.各采样点中PAHs组成主要以4环为主,占31.9%—100%,5环组分仅次于4环.相关性分析表明,PAHs低环(2—3环)与中环(4环)组分之间相关性更强,且二者与TOC相关性较高环组分显著.50.0%的采样点超过荷兰土壤标准目标参考值,该钢铁厂表层土壤已处于中等风险水平,污染主要集中在球团厂、焦化厂、炼铁厂和厂前交通繁忙区.其土壤潜在风险已呈增加趋势,有必要进行能源结构改造并加强污染监控.  相似文献   

6.
土壤多环芳烃(PAHs)的污染日益受到关注,PAHs是垃圾渗滤液中的主要有害成分之一.以苏北某市城郊结合部露天垃圾堆放场为对象,采用高效液相色谱法分析周边农田土壤中16种PAHs的含量特征及分布规律.结果表明,垃圾场周边农田土壤PAHs含量总体表现为随距垃圾堆体的距离增大而降低的趋势.土壤中PAHs总量(平均值为1 208.5μg·kg-1)明显高于未污染土壤(509.25μg·kg-1),其中显著提高了土壤中难降解、难挥发的4环芳烃的含量,按照欧洲农业土壤PAHs含量与分布标准,达到中等或中等以上PAHs污染水平,说明垃圾堆填场周边农田土壤存在PAHs的污染风险.  相似文献   

7.
土壤的芘污染与土壤酶活性   总被引:2,自引:0,他引:2  
选择芘作为多环芳烃(PAHs)代表污染物、敏感土壤酶作为污染物的生态毒理指标,探讨芘暴露下土壤酶活性的变化。结果表明:芘的添加浓度>50μg·kg-1时,对土壤脲酶、土壤脱氢酶活性有先抑制、后激活的作用,对土壤磷酸酶活性有激活作用;芘的添加浓度为50~1200μg·kg-1时,对土壤过氧化氢酶活性没有影响。土壤脲酶、脱氢酶、磷酸酶活性有可能作为芘污染土壤的生态毒理指标。  相似文献   

8.
将一种新型被动式采样器——三油酸甘油酯-醋酸纤维素复合膜(TECAMs)暴露于10种人工老化土壤中富集萘、菲、芘和苯并[a]芘4种多环芳烃(PAHs),并与土壤模型动物——赤子爱胜蚓(Eiseniafoetida)进行比较以研究该采样器用于评价土壤中多环芳烃生物可利用性的可能性.研究结果表明,TECAMs能有效富集土壤中萘、菲、芘和苯并[a]芘,并在48h内基本达到平衡,远快于赤子爱胜蚓的21d平衡时间.TECAMs内PAHs含量与土壤溶解有机碳(DOC)含量呈正相关(p<0.05),而与土壤中总有机质(TOM)含量呈负相关(p<0.05),土壤pH对TECAMs富集PAHs的影响不显著(p<0.05).TECAMs内PAHs含量与土壤中PAHs含量、赤子爱胜蚓体内PAHs含量均呈显著线性正相关(p<0.05,p<0.01).研究结果表明TECAMs有可能应用于评价土壤中PAHs的生物可利用性.  相似文献   

9.
青岛地区大气气溶胶中多环芳烃的GC/MS分析   总被引:3,自引:0,他引:3  
潘静  周成  郇宁  杨永亮  殷效彩 《环境化学》2003,22(3):311-312
本文采集了青岛5个区的大气气溶胶样品,参照美国EPA610方法,用GC/MS分析鉴定多环芳烃。结果表明,青岛市大气气溶胶中PAHs总量的总趋势是东部高于西部,中部高于南、北部。多环芳烃的环数分布表明,气溶胶中PAHs几乎全部由人类活动产生。16种优先控制多环芳烃化合物中的萘、苊、芴、荧蕙、茚并[1,2,3-cd]芘,苯并[b]荧蒽、苯并[k]荧蒽等有毒有害有机污染物普遍检出于市内五区。苯并[a]芘的大气含量甚微。  相似文献   

10.
太湖梅梁湾沉积物中多环芳烃的生态和健康风险   总被引:12,自引:4,他引:8  
持久性有机物引起的水质安全性问题日益受到广泛的关注.利用生态和健康风险评价的原理和方法,对太湖梅梁湾水源地沉积物中的多环芳烃可能导致的负面效应进行了分析.首先采用商值法筛选出该地区沉积物中具有潜在风险的多环芳烃,再进一步用建立在暴露浓度分布和物种敏感度分布上的概率法定量表征风险.结果表明,太湖梅梁湾水源地沉积物的多环芳烃中,菲、荧蒽、芘、苯并[a]蒽、屈、苯并[a]芘、二苯并[a,h]蒽7种具有潜在风险;在保护95%的物种水平下,菲的风险最小,而荧蒽和芘风险较高,达20%.健康风险分析表明,美国EPA提出的7种具有遗传毒性的多环芳烃其致癌风险在梅梁湾沉积物中均在10-5水平以下.  相似文献   

11.
A bioblitz inexpensively and quickly generates biodiversity data, but bioblitzes are often conducted with haphazard, unreplicated sampling. Results tend to be taxonomically, geographically, or temporally biased, lack metadata, and consist of lists of observed taxa that do not enable further analyses or correction for imperfect detection. A rapid, recurring, structured survey (RRSS) uses a structured sampling design and temporal and spatial replication to survey randomly selected sites on a conservation property. We participated in a loosely structured bioblitz and a subsequent RRSS at Big Canoe Creek Nature Preserve in Springville (St. Clair County), Alabama (USA) to compare observed richness derived from the 2 survey approaches. The RRSS data structure enabled us to fit models that accounted for imperfect detection to estimate abundances, occupancy probabilities, and habitat associations. The loosely structured bioblitz data could not be used in such models. We present a new integrated multispecies abundance model that we applied to avian RRSS data. Our model extension enables estimation for the community, employs data augmentation to estimate the number of undetected species, and incorporates covariates. The RRSS generated a more comprehensive and less biased list of observed taxonomic richness than the loosely structured bioblitz (e.g., 73 vs. 45 bird species and 104 vs. 63 insect families from the RRSS vs. loosely structured bioblitz, respectively). Models fit to the RRSS data identified seasonal patterns in avian community composition and allowed for estimation of habitat–occupancy relationships for insect taxa. The RRSS protocol has potential for broad transferability as a standardized, quick, and inexpensive way to inventory biodiversity and estimate ecological parameters while providing an outreach opportunity.  相似文献   

12.
Land-use change via human development is a major driver of biodiversity loss. To reduce these impacts, billions of dollars are spent on biodiversity offsets. However, studies evaluating offset project effectiveness that examine components such as the overall compliance and function of projects remain rare. We reviewed 577 offsetting projects in freshwater ecosystems that included the metrics project size, type of aquatic system (e.g., wetland and creek), offsetting measure (e.g., enhancement, restoration, and creation), and an assessment of the projects’ compliance and functional success. Project information was obtained from scientific and government databases and gray literature. Despite considerable investment in offsetting projects, crucial problems persisted. Although compliance and function were related to each other, a high level of compliance did not guarantee a high degree of function. However, large projects relative to area had better function than small projects. Function improved when projects targeted productivity or specific ecosystem features and when multiple complementary management targets were in place. Restorative measures were more likely to achieve targets than creating entirely new ecosystems. Altogether the relationships we found highlight specific ecological processes that may help improve offsetting outcomes.  相似文献   

13.
Protected areas (PAs) are often implemented without consideration of already existing PAs, which is likely to cause an overrepresentation of certain biophysical conditions. We assessed the representativeness of the current PA network with regard to the world's biophysical conditions to highlight which conditions are underprotected and where these conditions are located. We overlaid terrestrial and marine PAs with information on biophysical conditions (e.g., temperature, precipitation, and elevation) and then quantified the percentage of area covered by the PA network. For 1 variable at a time in the terrestrial realm, high temperature, low precipitation, and medium and very high elevation were underrepresented. For the marine realm, low and medium sea surface temperature (SST), medium and high sea surface salinity (SSS), and the deep sea were underrepresented. Overall, protection was evenly distributed for elevation across the terrestrial realm and SST across the marine realm. For 2 variables at a time, cold and very dry terrestrial environments had mostly low protection, which was also the case for low SST and low and medium SSS across most depths for marine environments. Low protection occurred mostly in the Sahara and the Arabian Peninsula for the terrestrial realm and along the Tropic of Capricorn and toward the poles for the marine realm. Although biodiversity measures are of prime importance for the design of PA networks, highlighting biophysical gaps in current PAs adds a frequently overlooked perspective. These gaps may weaken the potential of PAs to conserve biodiversity. Thus, our results may provide useful insights for researchers, practitioners, and policy makers to establish a more comprehensive global PA network.  相似文献   

14.
Summary The adaptation of defensive secretions to their target organisms was examined for the abdominal gland secretions ofBledius furcatus, B. spectabilis andB. arenarius. Therefore the target organisms of the secretion of theseBledius species (i.e. their predators) had to be identified. At the collection sites examined these were the earwigLabidura riparia, the antCataglyphis bicolor, the flyLispe candicans, different carabids of the generaPogonus, Dichirotrichus, Dyschirius, Bembidion andCalathus and the wading birdsHaematopus ostralegus andCalidris alba. The secretion of the abdominal glands contains the toxin ptoluquinone dissolved in either-dodecalactone and 1-undecene (B. furcatus andB. spectabilis) or in octanoic acid and octyloctanoate (B. arenarius). The ratio of these solvents is species-specific. Application experiments using some of the natural insect predators (L. riparia, C. bicolor, Pogonus, Di. gustavii, Dyschirius) revealed that these solvent ratios provided a more effective deterrent than other possible ratios. Thus by combining the solvents in certain ratios, the capability of cuticular penetration and therefore the effectiveness of the defensive secretions are adapted to their natural targets.  相似文献   

15.
The politics of development includes subtexts of choice, as underpinned by community consensus (or lack of it), against the larger backdrop of a liberal democracy, with its intricate power structures that influence the choice of concepts and often lead to complicity rather than consent. A dilemma exists between the understanding of field-level practitioners and that of academics, whose understandings of progress differ. Progress can (and often does) imply long-term change across generations whereas development is often more a matter of crisis management and delivering tangible results to end-users. This makes it a bone of contention across political systems, irrespective of local or global dynamics. Development can emerge as a tool to be wielded for power and further political mileage at the expense of progress. Progress cannot be studied as a counterpoint to development as the sense of history is often missing in development interventions. Development tends to be piecemeal as its very logic often stems from the rationale of power. This is not to suggest, however, that development is only about politics; it is definitely more than the politics of everyday life and involves all of civil society that requires its critical and immediate attention. In this sense, it has become a priority for politicians with an underlying agenda designed to out-manouevre dissent and all statements of protest.  相似文献   

16.
An argument is presented in which areas of natural arsenic contamination of modern groundwaters throughout Asia have a common origin. Arsenic originally accumulated in oceanic ferro-manganoan sediments of the eastern Palaeo-Tethys. This was further concentrated through oceanic crustal extinction in what later became the south-east Chinese accreted mineralised terrain. Proto-Himalayan uplift of this area created the palaeo-drainage systems of the Ganges – Brahmaputra, Irrawaddy, Mekong, and Red Rivers, with consequent headwater erosion of arsenic-rich sediments. Their downstream deposition as immature and easily redistributed Neogene sandstones, silts, and iron-rich clays has created secondary and tertiary reservoirs of adsorbed and authigenic arsenic, from which the current arsenic-rich groundwaters have evolved. Considering river basins within the above palaeo-hydrogeological framework provides a basis for assessing the risk of arsenic in groundwater basins of south and south-eastern Asia.  相似文献   

17.
As landscapes continue to fall under human influence through habitat loss and fragmentation, fencing is increasingly being used to mitigate anthropogenic threats and enhance the commercial value of wildlife. Subsequent intensification of management potentially erodes wildness by disembodying populations from landscape-level processes, thereby disconnecting species from natural selection. Tools are needed to measure the degree to which populations of large vertebrate species in formally protected and privately owned wildlife areas are self-sustaining and free to adapt. We devised a framework to measure such wildness based on 6 attributes relating to the evolutionary and ecological dynamics of vertebrates (space, disease and parasite resistance, exposure to predation, exposure to limitations and fluctuations of food and water supply, and reproduction). For each attribute, we set empirical, species-specific thresholds between 5 wildness states based on quantifiable management interventions. We analysed data from 205 private wildlife properties with management objectives spanning ecotourism to consumptive utilization to test the framework on 6 herbivore species representing a range of conservation statuses and commercial values. Wildness scores among species differed significantly, and the proportion of populations identified as wild ranged from 12% to 84%, which indicates the tool detected site-scale differences both among populations of different species and populations of the same species under different management regimes. By quantifying wildness, this framework provides practitioners with standardized measurement units that link biodiversity with the sustainable use of wildlife. Applications include informing species management plans at local scales; standardizing the inclusion of managed populations in red-list assessments; and providing a platform for certification and regulation of wildlife-based economies. Applying this framework may help embed wildness as a normative value in policy and mitigate the shifting baseline of what it means to truly conserve a species.  相似文献   

18.
Abstract: In the United States, as elsewhere, a growing debate pits national energy policy and homeland security against biological conservation. In rural communities the extraction of fossil fuels is often encouraged because of the employment opportunities it offers, although the concomitant itinerant workforce is often associated with increased wildlife poaching. We explored possible positive and negative factors associated with energy extraction in the Greater Yellowstone Ecosystem (GYE), an area known for its national parks, intact biological diversity, and some of the New World's longest terrestrial migrations. Specifically, we asked whether counties with different economies—recreation (ski), agrarian (ranching or farming), and energy extractive (petroleum)—differed in healthcare (gauged by the abundance of hospital beds) and in the frequency of sexual predators. The absolute and relative frequency of registered sex offenders grew approximately two to three times faster in areas reliant on energy extraction. Healthcare among counties did not differ. The strong conflation of community dishevel, as reflected by in‐migrant sexual predators, and ecological decay in Greater Yellowstone is consistent with patterns seen in similar systems from Ecuador to northern Canada, where social and environmental disarray exist around energy boomtowns. In our case, that groups (albeit with different aims) mobilized campaigns to help maintain the quality of rural livelihoods by protecting open space is a positive sign that conservation can matter, especially in the face of rampant and poorly executed energy extraction projects. Our findings further suggest that the public and industry need stronger regulatory action to instill greater vigilance when and where social factors and land conversion impact biological systems.  相似文献   

19.
How should managers choose among conservation options when resources are scarce and there is uncertainty regarding the effectiveness of actions? Well‐developed tools exist for prioritizing areas for one‐time and binary actions (e.g., protect vs. not protect), but methods for prioritizing incremental or ongoing actions (such as habitat creation and maintenance) remain uncommon. We devised an approach that combines metapopulation viability and cost‐effectiveness analyses to select among alternative conservation actions while accounting for uncertainty. In our study, cost‐effectiveness is the ratio between the benefit of an action and its economic cost, where benefit is the change in metapopulation viability. We applied the approach to the case of the endangered growling grass frog (Litoria raniformis), which is threatened by urban development. We extended a Bayesian model to predict metapopulation viability under 9 urbanization and management scenarios and incorporated the full probability distribution of possible outcomes for each scenario into the cost‐effectiveness analysis. This allowed us to discern between cost‐effective alternatives that were robust to uncertainty and those with a relatively high risk of failure. We found a relatively high risk of extinction following urbanization if the only action was reservation of core habitat; habitat creation actions performed better than enhancement actions; and cost‐effectiveness ranking changed depending on the consideration of uncertainty. Our results suggest that creation and maintenance of wetlands dedicated to L. raniformis is the only cost‐effective action likely to result in a sufficiently low risk of extinction. To our knowledge we are the first study to use Bayesian metapopulation viability analysis to explicitly incorporate parametric and demographic uncertainty into a cost‐effective evaluation of conservation actions. The approach offers guidance to decision makers aiming to achieve cost‐effective conservation under uncertainty.  相似文献   

20.
Summary Acanthoscelides obtectus (Say) is one of the most damaging pests of kidney beans,Phaseolus vulgaris L. worldwide. However, aromatic plants from the families Lamiaceae, Lauraceae, Myrtaceae and Poaceae can protect kidney beans by direct or delayed insecticidal effect, through increased adult mortality and inhibition of beetle reproduction (both oviposition and adult emergence). The efficiency of hydrodistillated and intact plants fromThymus vulgaris andT. serpyllum, Mentha piperata, Rosmarinus officinalis, Satureia hortensis, Eucalyptus globulus, Laurus nobilis, Origanum vulgare, andCymbopogon nardus was compared. For both extracts,Origanum vulgare had the best effect. The insecticidal effect was induced by more than the essential oils because no significant difference was noticed between distilled and intact plants extract. Inhibition of reproduction was particularly important. These results suggest that lipidic as well as non lipidic, allelochemicals, such as phenolics, or non-protein amino-acids, or flavonoids may be involved in the toxicity of aromatic plants to this beetle.  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