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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.
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   

4.
调查京津冀地区工业土壤污染的状况及其与土壤生物因子的相互关系,为后续环境监测及修复提供参考。在京津冀地区代表性工业园区采集土壤样品,分析其中半挥发有机污染和土壤生物状况。土壤采集点周边的工业产业涵盖了金属冶炼及压延加工业,石油加工业、炼焦及核燃料加工业,交通运输设备制造业,化学原料及化学制品制造业等北方地区典型重工业产业。结果表明,芘(Pyrene,Pyr)、荧蒽(Fluoranthene,Flu)、邻苯二甲酸二(2-二乙基己基)酯(Bis(2-diethylhexyl) Phthalate,DEHP)检出排名前3,分别有98.4%、98.4%、96.9%的点位浓度高于检出限,其最高质量分数分别为2.84、2.79、5.72 mg·kg-1。土壤中多环芳烃(Polycyclic Aromatic Hydrocarbons,PAHs)以4-6环PAHs为主,∑16PAHs质量分数中位值为0.67 mg·kg-1,约有90.6%的样品中苯并[a]芘(Benzo[a]pyrene,BaP)的浓度高于检出限。荧蒽、芘、苯并[a]蒽(Benzo[a]a...  相似文献   

5.
石油污染土壤中多环芳烃分析及生态风险评价   总被引:1,自引:0,他引:1  
对中原油田石油污染土壤中多环芳烃(PAHs)的残留量进行了调查。结果表明,PAHs总残留量范围为70.8~5 013.2μg.kg-1,且以3环以上多环芳烃组分为主。其中,苯并[a]芘检出率为100%,采油树前地表土壤苯并[a]芘检出量很高,最高可达996.9μg.kg-1。参考加拿大农业区域土壤PAHs的治理标准值,采用内梅罗综合指数法进行评价的结果表明:运行中和停产时间较短的油井周围土壤的生态风险较高;油井运行状态、停产时间及距采油树(污染源)的距离对土壤的生态风险都有影响,油井停产时间越长,其周围土壤的生态风险随之降低,距污染源越远,土壤生态风险越低。  相似文献   

6.
本文采集并分析了新疆准东煤矿开采区域6个采样点的降尘、土壤和植物的样品,对样品中16种多环芳烃(PAHs)的含量进行了分析,结果显示,降尘中∑PAHs在1.07—8.34 mg·kg~(-1)间;土壤中(除1#点位)∑PAHs在0.134—1.06 mg·kg~(-1)间;植物中(除1#点位)∑PAHs在0.163—1.54 mg·kg~(-1)间.降尘中高含量PAHs主要为苯并[b]荧蒽、菲和萘;土壤中高含量PAHs主要为菲、荧蒽和蒽;植物中高含量PAHs主要为萘、菲和芴.降尘、土壤及植物中PAHs均显示出富三环的特征;研究区域土壤中PAHs的苯并(a)芘等效毒性当量结果显示,研究区域土壤中PAHs的污染存在一定的潜在风险.  相似文献   

7.
采用高效液相色谱技术(HPLC)对徐州市大气颗粒物中优控的16种多环芳烃(PAHs)进行定量研究。结果表明:萘、芴、苊等低分子量芳烃的含量相对较低;苯并(g,h,i)苝、茚并(1,2,3-cd)芘、苯并(k)荧蒽、苯并(a)芘等高分子量芳烃的含量相对较高;含量最高的单体为荧蒽,占待检的16种PAHs的19%以上。不同环数多环芳烃含量大小顺序为:4环〉5环〉6环〉3环〉2环。可吸入颗粒物(PM10)中苯并(a)芘和∑PAHs在不同功能区的分布特征大体上一致,并呈现一定规律性:交通干线区〉工业区〉风景文化区〉居民区〉新城区。由此可以初步认为徐州市区PM10中的PAHs主要来源于燃煤和汽车尾气。  相似文献   

8.
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   

9.
考察了高铁酸钾对荧蒽和苯并[a]芘两种PAHs(多环芳烃)的降解反应过程,并应用偏振荧光光谱技术研究了荧蒽和苯并[a]芘两种PAHsr降解体系反应过程及其差别的识别,着重探讨了两种PAHs降解体系反应过程中的多种荧光波长模式与偏振度、三维荧光(EEM)与偏振三维荧光(PEEM)变化规律,最后由时间扫描荧光模式直接获得反应动力学拟合方程式.实验结果表明,各荧光识别模式一致地显示出高铁酸钾对荧蒽和苯并[a]芘的显著性降解作用及其对应的各荧光强度变化规律,即反应时间大于40 s后,两种PAHs(多环芳烃)的降解反应均不明显,且降解过程中均无新的荧光发色团结构生成.在高铁酸钾与荧蒽/苯并[a]芘摩尔比为1∶1、1∶4、4∶1的各降解体系的反应过程均符合一级反应动力学规律.荧蒽降解曲线的线性关系更高,苯并芘降解速率更快,多种荧光光谱相结合能够实现对PAHs的降解过程的便捷而有效的追踪,其揭示的结果与分子机理一致,即苯并[a]芘分子较荧蒽分子具有更大的π电子密度,因而在Fe(Ⅵ)夺电子过程中,更易于失去电子而被Fe(Ⅵ)氧化降解.  相似文献   

10.
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   

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.
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   

14.
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   

15.
Parasitic wasps orient to green leaf volatiles   总被引:12,自引:0,他引:12  
Summary Undamaged plants emit low levels of green leaf volatiles (GLVs), while caterpillar-damaged and artificially damaged plants emit relatively higher levels of certain GLVs. Female braconid parasitoids,Microplitis croceipes, oriented to both damaged plants and to individual GLVs in no-choice tests in a wind tunnel, but seldom oriented to undamaged plants. Female ichneumonid parasitoids,Netelia heroica, also oriented to individual GLVs in a wind tunnel. Males of both wasp species failed to orient to the GLVs. These data show that leaf-feeding caterpillars can cause the release of GLVs, and that parasitic wasps can respond to these odors by flying upwind (chemoanemotactic response), which brings the wasps to their caterpillar hosts. This supports the hypothesis that plants communicate with members of the third trophic level,i.e., plants under herbivore attack emit chemical signals that guide natural enemies of herbivores to sites of plant damage. In this interaction, the GLVs serve as tritrophic plant-to-parasitoid synomones. That parasitoids from two different wasp families oriented to GLVs suggests that the response may be widespread among the Hymenoptera.Mention of a commercial or proprietary product does not constitute an endorsement by the U.S. Department of Agriculture  相似文献   

16.
Atlantic sturgeon (Acipenser oxyrhynchus) populations have been declared either endangered or threatened under the U.S. Endangered Species Act. Effective measures to repel sturgeon from fishing gear would be beneficial to both fish and fishers because they could reduce both fishery‐associated mortality and the need for seasonal and area closures of specific fisheries. Some chondrostean fishes (e.g., sturgeons and paddlefishes) can detect weak electric field gradients (possibly as low as 5 Μv/cm) due to arrays of electroreceptors (ampullae of Lorenzini) on their snout and gill covers. Weak electric fields, such as those produced by electropositive metals (typically mixtures of the lanthanide elements), could therefore potentially be used as a deterrent. To test this idea, we recorded the behavioral responses of juvenile Atlantic sturgeon (31–43 cm fork length) to electropositive metal (primarily a mixture of the lanthanide elements neodymium and praseodymium) both in the presence and absence of food stimuli. Trials were conducted in an approximately 2.5 m diameter × 0.3 m deep tank, and fish behaviors were recorded with an overhead digital video camera. Video records were subsequently digitized (x, y coordinate system), the distance between the fish and the electropositive metal calculated, and data summarized by compiling frequency distributions with 5‐cm bins. Juvenile sturgeon showed clear avoidance of electropositive metal but only when food was present. On the basis of our results, we conclude that the electropositive metals, or other sources of weak electric fields, may eventually be used to reduce the interactions of Atlantic sturgeon with fishing gear, but further investigation is needed. El Potencial del Metal Electropositivo para Reducir las Interacciones del Esturión Atlántico con Instrumentos de Pesca Bouyoucos, Bushnell & Brill 13–003  相似文献   

17.
Many conservation actions are justified on the basis of managing biodiversity. Biodiversity, in terms of species richness, is largely the product of rare species. This is problematic because the intensity of sampling needed to characterize communities and patterns of rarity or to justify the use of surrogates has biased sampling in favor of space over time. However, environmental fluctuations interacting with community dynamics lead to temporal variations in where and when species occur, potentially affecting conservation planning by generating uncertainty about results of species distribution modeling (including range determinations), selection of surrogates for biodiversity, and the proportion of biodiversity composed of rare species. To have confidence in the evidence base for conservation actions, one must consider whether temporal replication is necessary to produce broad inferences. Using approximately 20 years of macrofaunal data from tidal flats in 2 harbors, we explored variation in the identity of rare, common, restricted range, and widespread species over time and space. Over time, rare taxa were more likely to increase in abundance or occurrence than to remain rare or disappear and to exhibit temporal patterns in their occurrence. Space–time congruency in ranges (i.e., spatially widespread taxa were also temporally widespread) was observed only where samples were collected across an environmental gradient. Fifteen percent of the taxa in both harbors changed over time from having spatially restricted ranges to having widespread ranges. Our findings suggest that rare species can provide stability against environmental change, because the majority of species were not random transients, but that selection of biodiversity surrogates requires temporal validation. Rarity needs to be considered both spatially and temporally, as species that occur randomly over time are likely to play a different role in ecosystem functioning than those exhibiting temporal structure (e.g., seasonality). Moreover, temporal structure offers the opportunity to place management and conservation activities within windows of maximum opportunity.  相似文献   

18.
Summary. Myrmecophytic plants use obligate ant mutualists as a constitutive indirect defence mechanism. These plants often produce cellular food bodies (FBs) to nourish their resident ants. Lipids, proteins, and even highly specialised compounds such as glycogen have been reported from FBs, but detailed chemical analyses of FB composition have so far been presented only for Southeast Asian Macaranga and Central American Piper myrmecophytes. Here we report the chemical composition of FBs of five myrmecophytic Acacia (Fabaceae) species from Mexico using HPLC (carbohydrates and proteins) and GC-MS (lipids). Feeding experiments revealed no hints on any use of external food sources by the inhabiting Pseudomyrmex ants. These ants obviously rely completely on FBs and extrafloral nectar provided by their hosts. The total content of nutrients in Acacia FBs was 15-25% of FB dry mass, being much lower than in Macaranga or Piper FBs. Proteins were dominating (8-14 % dm) in Acacia FBs and thus were present in higher amounts than in Macaranga FBs, yet in lower amounts than in Piper. Lipids contributed 1-9 % of dry mass, showing a lower proportion than in FBs of Macaranga or Piper. Carbohydrates made up 3-11 % dm, reaching in most Acacia species the same range as observed in Macaranga and in Piper FBs. Water content was 18-24 % of FB fresh mass, and structural tissue obviously made up a much higher proportion in Acacia FBs than in Macaranga or Piper FBs. Both characters might represent an adaptation to producing FBs unprotected at the leaf tips under dry conditions. Acacia FBs contain all amino acids and all fatty acids that are considered essential for insects, and their contents of lipids and proteins are higher than in the leaves from which they are ontogenetically derived. This indicates a putatively adaptive enrichment of nutritionally valuable compounds in structures functioning as ant-food.  相似文献   

19.
Conservation biologists are generally united in efforts to curtail the spread of non‐native species globally. However, the colonization history of a species is not always certain, and whether a species is considered non‐native or native depends on the conservation benchmark. Such ambiguities have led to inconsistent management. Within the Tongass National Forest of Alaska, the status of American marten (Martes americana) on the largest, most biologically diverse and deforested island, Prince of Wales (POW), is unclear. Ten martens were released to POW in the early 1930s, and it was generally believed to be the founding event, although this has been questioned. The uncertainty surrounding when and how martens colonized POW complicates management, especially because martens were selected as a design species for the Tongass. To explore the history of martens of POW we reviewed other plausible routes of colonization; genetically and isotopically analyzed putative marten fossils deposited in the late Pleistocene and early Holocene to verify marten occupancy of POW; and used contemporary genetic data from martens on POW and the mainland in coalescent simulations to identify the probable source of the present‐day marten population on POW. We found evidence for multiple routes of colonization by forest‐associated mammals beginning in the Holocene, which were likely used by American martens to naturally colonize POW. Although we cannot rule out human‐assisted movement of martens by Alaskan Natives or fur trappers, we suggest that martens be managed for persistence on POW. More generally, our findings illustrate the difficulty of labeling species as non‐native or native, even when genetic and paleo‐ecological data are available, and support the notion that community resilience or species invasiveness should be prioritized when making management decisions rather than more subjective and less certain conservation benchmarks.  相似文献   

20.
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