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 62 毫秒
1.
通过对北京市通州污灌区土壤现状调查与蔬菜重金属污染监测,结合土壤环境质量标准、食品卫生标准及污灌区污染历史,分析对比该区土壤和蔬菜重金属污染状况及其变化。结果表明,本次监测通州污灌区土壤中重金属平均含量均达到土壤环境质量标准(GB15618-1995)中二级标准限量。对照土壤中的重金属Cu、Pb、Cr、Cd和As均达到土壤一级标准。凉水河两岸和通惠北干渠中重金属含量均高于对照土壤,说明污灌区污水灌溉已使土壤受到一定程度的污染。与二十世纪70年代末监测结果相比,土壤中多数重金属含量处于上升趋势。污灌区蔬菜重金属含量监测结果表明,其含量水平均达到食品卫生标准,说明污灌区蔬菜尚未受到严重污染。  相似文献   

2.
淮安市环境监测中心站于1999年-2000年对淮安市农产品中重金属以及有机氯、有机磷农药残留量进行了调查。结果表明,粮食和蔬菜作物中,六六六的4种同分异构体只有γ-六六六能检出,检出率分别为24.0%和51.7%,都未超标;DDT的4种同分异要体均未检出;有机磷农药的检出率分别为5%和25%,其中蔬菜中敌敌畏含量出现个别超标现象,倍硫磷、乐果和杀螟松在粮食和蔬菜作物中的含量都不超标。重金属中金属“五毒”在粮食和蔬菜作物中,只有Cr和Pb能检出,Cd、Hg和As都未检出,Cu、Zn和Mn能检出,但不超标。提出,应严格按照农牧渔业部和卫生部颁发的《农药安全使用规定》用药,多使用高效低残留量的“绿色农药”;农业、环保和卫生部门必须加强合作,对蔬菜生产销售的全过程进行监督监测,以确保生产无公害蔬菜。  相似文献   

3.
杭州地区农业土壤中重金属的分布特征及其环境意义   总被引:1,自引:0,他引:1  
为了分析杭州地区农业土壤重金属的分布特征及其环境意义,通过现场采样和室内分析检测的方法,对杭州市各区县不同作物农业土壤表层土中的Hg、As、Cu、Pb、Cr、Cd 6种重金属元素进行检测,并对其分布特征进行了分析。结果表明,杭州地区农业土壤中除As外,其他5种重金属的平均含量均低于且接近浙江省土壤背景值,个别采样点的重金属含量超过了土壤环境质量国家二级标准。总体上,杭州地区农业土壤处于安全水平。通过重金属的区域分布特征分析表明,余杭区和富阳市农业土壤中重金属平均含量普遍高于其他区域。萧山区和建德市部分农业土壤则存在Cu和Hg含量较高的情况,而淳安县农业土壤中重金属含量差异较大,土壤中出现了As、Cr和Cd含量最大值。不同作物的农业土壤重金属含量存在一定的差异,但不明显。水稻田和蔬菜地的土壤中,重金属含量较其他作物种植类型的土壤中含量高;叶菜类(蔬菜、茶叶)作物土壤中的Cd含量要比根茎类(水稻)、茄果类(水果)及其他作物种植类型的土壤中的含量低。目前杭州地区土壤中6种重金属含量均对作物的直接危害不大,但由于萧山区个别采样点Cu含量严重超标,淳安县土壤中Cd受外源性来源影响也已较明显,需要相关部门加大监管力度,防止污染事件发生。同时,为防止农业土壤中重金属含量进一步升高,需要加大大气降尘监测与治理、废气污染监管与控制治理。  相似文献   

4.
西南某省14种尾矿重金属浸出量及总量分析   总被引:1,自引:1,他引:0  
研究中国西南某省不同类型尾矿的重金属浸出量及总量,为尾矿的污染防范、环境管理和综合利用提供参考和建议。采集了14种类型共164个有代表性尾矿进行浸出毒性试验,并分析其中79个典型尾矿样品的9种重金属含量,以评估其污染风险和综合利用价值。结果表明,有5种类型共7个样品出现浸出毒性超标,分别为铅锌矿、镍矿、银矿、铁矿、锰矿,总体超标率为4.3%。超标元素分别为砷、镉、锌、铅、铜、镍等6种元素,最大超标倍数分别为砷18.3倍、锌4.8倍、镉3.0倍、铅0.56倍、铜0.32倍、镍0.16倍;尾矿含有较多重金属,其中砷、锌、铅、铜含量较高,最高分别达到11.75%、2.60%、1.01%、0.29%,不同类型尾矿其重金属含量各有不同,铅锌矿尾矿的重金属总量最高。总体上,该省绝大多数尾矿为普通固废,少部分为危险废物,砷、镉、锌、铅、铜、镍等6种元素存在污染风险,其中砷元素是最主要污染物;尾矿由于重金属含量较高而有一定的综合利用价值。  相似文献   

5.
南京市郊区基本农田保护区土壤重金属污染调查   总被引:5,自引:0,他引:5       下载免费PDF全文
为调查基本农田保护区土壤环境中重金属污染状况,江苏省农业环境监测站于1999年和2001年分别对南京市郊区基本农田土壤环境质量进行了监测,共计布设监测点14个,监项目为镉,铅,砷,汞,铬和pH,结果表明,1999年土壤样品的重金属检出率为97.1%,超标率为5.7%,2001年重金属检出率为100%,超标率为1.4%,1999年土壤样品中超标的重金属元素是镉,超标率为28.6%,2001年超标元素是汞,超标率为7.1%,1999年土壤综合污染指数为1.08,污染等级及污染水平均属轻污染;2001年土壤综合污染指数为0.76,污染等级为警戒线,污染水平达到尚清洁。  相似文献   

6.
采用苔藓植物大灰藓作为监测物种,考察Pb、Zn、Cu、Cd、Cr、Hg等6种重金属元素在大气中的分布情况,分析研究区域内各样点大灰藓和土壤中的6种重金属含量。结果表明,大灰藓中重金属含量依次为ZnPbCrCuCdHg,土壤中重金属含量依次为ZnPbCrCuHgCd。通过Kriging插值运算,得到6种重金属元素含量等值分布图,直观地体现了6种重金属元素的空间分布,说明大气重金属空间分布与区域产业类型及发展状况紧密相关。  相似文献   

7.
测定南京某农药厂附近大米、蔬菜及肉类中11种有机磷农药含量,通过使用气相色谱/质谱联用的方法,建立GC/MS定性定量分析方法,检出限达到0.05μg/kg(肉类)和0.1μg/kg(大米和蔬菜),回收率均符合测定要求。环境样品监测结果显示,大米和蔬菜中有机磷农药的含量高于肉类中的含量,说明在大米和蔬菜表面残留的农药量要高于进入生物体体内的含量。南京蔬菜样品中有机磷农药高于常州蔬菜样品,说明农药厂对蔬菜表面残留农药量有影响。不同的有机磷农药在不同的介质中,检出情况不一样,说明不同的环境介质对有机磷农药的保留水平不一样。  相似文献   

8.
通过对攀西区域安宁河流域的7个断面底泥以及该区域17家典型涉重金属工业周边土壤进行环境质量状况调查和生态风险评价,结果显示,底泥中6种重金属砷、铬、铅、镉、汞和钒含量在凉山州境内特别是冕宁县断面含量最高,污染最重,攀枝花境内米易县部分含量较低;底泥中铅、镉和砷等出现了中重度污染,且钒和铬含量、砷和镉含量之间分别呈极显著和显著相关,同源性特征明显,土壤中镉超标范围最广,超标程度最重且呈面状重度风险,钒和汞超标范围较大,汞出现较重风险,其余为低度风险。  相似文献   

9.
以江苏省中部某城镇工业遗留场地为研究区域,采集23件土壤样品,检测土壤中多环芳烃(PAHs)、有机氯农药(OCPs)、总石油烃(TPH)和重金属含量并开展风险评估。结果表明:土壤中有机物检出因子18项均无超标;Zn和Cr最大值均超过浙江住宅及公共用地筛选值,其余重金属未超标。风险评估表明,在第一类用地和第二类用地中Cd的致癌风险分别为2.70×10-8和1.42×10-8,均小于可接受致癌风险10-6;在第一类用地和第二类用地中Cd、Cu、Hg、Zn危害熵范围分别为 0.023~0.542和0.006~0.060,均小于可接受非致癌危害熵1。Cd、Cu、Hg、Zn风险值均在可接受范围内。  相似文献   

10.
于2017年11月,采集了上海市苏州河华漕、松浦大桥、大泖港3个典型水域水葫芦样品,采用电感耦合等离子体质谱法和冷原子吸收分光光度法,分析了水葫芦中14种重金属含量和吸附规律。结果表明:3个典型区域中,苏州河华漕水葫芦中重金属含量最高,且Cr含量超标,不可作为饲料原料应用,松浦大桥、大泖港的水葫芦内重金属含量符合饲料卫生标准,可作为饲料原料进行应用;水葫芦对重金属的吸收含量依次为Mn> Zn> Ni> Cu> Co> V> Pb> Cr> As> Sb> Cd> Hg> Ag> Tl,对Mn具有超富集能力,可考虑作为Mn污染修复植物进行应用;水葫芦不同部位对重金属(除Hg外)的富集能力表现为根>茎、叶,不同水葫芦植株中重金属含量受生长基质、株龄、个体吸附力差异等方面的影响。  相似文献   

11.
An important research area in life sciences is devoted to modeling, prediction, and dynamics of gene-expression patterns. As clearly understood in these days, this enterprise cannot become satisfactory without acknowledging the role of the environment. To a representation of past, present, and most likely future states, we also encounter measurement errors and uncertainties. This paper surveys and improves recent advances in understanding the foundations and interdisciplinary implications of the newly introduced gene–environment networks, and it integrates the important theme of carbon dioxide emission reduction into the networks and dynamics. We also introduce some operational and managerial issues of practical working and decision making, expressed in terms of sliding windows, quadrants (modules) of parametric effects, and navigating (controlling) between such effects and directing them. Given data from DNA microarray experiments and environmental records, we extract nonlinear ordinary differential equations that contain parameters that have to be determined. For this, we employ modern (Chebychevian) approximation and (generalized semi-infinite) optimization. After this is provided, time- discretized dynamical systems are studied. A combinatorial algorithm with polyhedra sequences allows to detect the region of parametric stability. Finally, we analyze the topological landscape of gene–environment networks with its structural (in)stability. By embedding as a module and investigating CO2 emission control and figuring out game theoretical aspects, we conclude. This pioneering work is theoretically elaborated, practically devoted to health care, medicine, education, living conditions, and environmental protection, and it invites the readers to future research.   相似文献   

12.
In this article a comprehensive approach for the evaluation of possible health effects in an environmental impact assessment (EIA) is described, illustrated with the example of Amsterdam Airport Schiphol. Unlike many EIAs, we estimated quantitatively the impact of aircraft-related pollution in terms of the number of affected people for aircraft noise annoyance, odour annoyance and hypertension. In addition, an analysis of health registry data on cardiovascular and respiratory diseases and a short survey on annoyance and risk perception were carried out. The scope of a health impact assessment depends on the situation, available knowledge and data, concern in the population about the impact and the number of people concerned. It is important to pay attention to the perception of risks and concerns from all parties involved. Moreover, the results demonstrate that far more people outside the area for which standards apply were affected than inside.  相似文献   

13.
The San Francisco Bay estuary isused by over one million shorebirds during springmigration and is home to several hundred thousandduring the winter. Most shorebird use occurs in thesouthern reach of the estuary (South Bay). Thereduced water circulation and discharge fromindustrial sources in the South Bay are responsiblefor the highest levels of some trace elements in theestuary. Wintering shorebirds have been found to havestrong site fidelity to areas as small as a fewkilometers in the South Bay, which may increase theirexposure to contaminants near local point sources. Inaddition, different shorebird species foraging at thesame site have been shown to have differentcontaminant burdens. Thus, our objectives were totest whether contaminant burdens differed by species,or whether contaminant burdens differed in shorebirdscollected at adjacent sites. We examined thecontaminant profiles of two species of shorebirds,long-billed dowitchers (Limnodromus scolopaceus)and western sandpipers (Calidris mauri) thatforage together at two sites, Hayward and Newark,separated by 8 km in the South Bay. We usedmultivariate analysis of variance tests to compare thecomposition of 14 elemental analytes in their livertissues and estimated their molar ratios of Hg and Se. Composite samples were used for contaminant analysesbecause of the small body size of the shorebirds. Seven elemental analytes (Ag, Ba, Be, Cr, Ni, Pb, V)were below detection limits in a majority of thesamples so statistical analyses were precluded. Inthe measurable analytes (As, Cd, Cu, Hg, Mn, Se, Zn),we found no significant intra-site differences ofcontaminant profiles for the two species. We pooledthe samples to examine inter-site differences andfound significant differences in contaminant profilesbetween shorebirds at the neighboring sites (P = 0.03). Shorebirds at Newark had higher (P < 0.05) concentrations of As, Cd, and Se than those at Hayward. Dowitchers at Newark had concentrations of Hg and Se which were highly correlated (P < 0.003) in a mean molar ratio of 1:19, similar tothat reported in other birds. In the larger dowitcherspecies, we also examined exposure to 20organochlorine compounds. Organic analyses showedthat the dowitchers had been exposed to DDE, PCBs,dieldrin and trans-nonachlor, but with no significantdifferences in concentrations between Hayward andNewark (P > 0.05).  相似文献   

14.
土壤和底泥中砷、铬、锰测定的前处理技术   总被引:6,自引:0,他引:6  
试验了土壤和底泥中砷的前处理技术,其目的是能对土壤、底泥中砷、铬、锰在一次前处理中制备成试液,比色法分析。试验表明,用H2SO4-H3PO4-H2O2进行前处理是可行的。方法简单、挥发酸雾少,用标准参考物质检验证明,分解完全,数据准确,有粒较好一致性。  相似文献   

15.
This paper presents the chemical speciation and retention behavior of chromium (Cr), nickel (Ni), and cadmium (Cd) prior to and after the electrokinetic remediation in glacial till soil. The speciation of the metals was predicted using the chemical speciation program MINEQL+. The simulations were performed for single-contaminant with only Cr(VI) or Ni, and multi-contaminants consisting of: (1) Cr(VI), Ni, and Cd; (2) Cr(III), Ni and Cd; (3) Cr(VI), Cr(III), Ni and Cd; (4) Cr(VI), Ni, and Cd with reducing agents; and (5) Cr(III), Ni, and Cd with oxidizing agent (Mn). The results showed that the speciation and distribution of cationic metals [Ni, Cd, and Cr(III)] in glacial till soil remain unaffected or slightly affected during electrokinetics. This is attributed to the high pH buffering capacity of the glacial till, leading the metals to precipitate in the soil prior to and after electrokinetics. This study showed that during electrokinetics, Cr(VI) existed as anionic complex and migrated towards the anode and the migration is maximum in case of a single-contaminant system. The study also showed that near the anode in the absence of any reducing and oxidizing agent, Cr(VI) mostly adsorbed, and some of Cr(VI) reduced to Cr(III) and migrated towards the cathode and finally precipitated due to high pH conditions. Ni and Cd remain adsorbed or precipitated due to the high pH conditions throughout the soil. Among the reducing agents, the sulfide had significant effect on the migration of metals compared to ferrous ions. While in the presence of oxidizing agent (Mn), no noticeable Cr(VI) was found in the soil sample indicating the reduction of Cr(VI) to Cr(III) and the predominance of reducing conditions due to the presence of naturally occurring iron in the glacial till soil. Overall, this study provides a reasonable explanation of the speciation and distribution of chromium, nickel and cadmium during the electrokinetic remediation of glacial till soil.  相似文献   

16.
We evaluated exposure of aquatic biota to lead (Pb), zinc (Zn), and cadmium (Cd) in streams draining a Pb-mining district in southeast Missouri. Samples of plant biomass (detritus, periphyton, and filamentous algae), invertebrates (snails, crayfish, and riffle benthos), and two taxa of fish were collected from seven sites closest to mining areas (mining sites), four sites further downstream from mining (downstream sites), and eight reference sites in fall 2001. Samples of plant biomass from mining sites had highest metal concentrations, with means 10- to 60-times greater than those for reference sites. Mean metal concentrations in over 90% of samples of plant biomass from mining sites were significantly greater than those from reference sites. Mean concentrations of Pb, Zn, and Cd in most invertebrate samples from mining sites, and mean Pb concentrations in most fish samples from mining sites, were also significantly greater than those from reference sites. Concentrations of all three metals were lower in samples from downstream sites, but several samples of plant biomass from downstream sites had metal concentrations significantly greater than those from reference sites. Analysis of supplemental samples collected in the fall of 2002, a year of above-average stream discharge, had lower Pb concentrations and higher Cd concentrations than samples collected in 2001, near the end of a multi-year drought. Concentrations of Pb measured in fish and invertebrates collected from mining sites during 2001 and 2002 were similar to those measured at nearby sites in the 1970s, during the early years of mining in the Viburnum Trend. Results of this study demonstrate that long-term Pb mining activity in southeast Missouri has resulted in significantly elevated concentrations of Pb, Cd, and Zn in biota of receiving streams, compared to biota of similar streams without direct influence of mining. Our results also demonstrate that metal exposure in the study area differed significantly among sample types, habitats, and years, and that these factors should be carefully considered in the design of biomonitoring studies.  相似文献   

17.
18.
The present study demonstrates comparison of Cr accumulatingpotential by the plants of Najas indica Cham. (submerged),Vallisneria spiralis L. (rooted submerged) and Alternanthera sessilis R. Br. (rooted emergent) under repeatedmetal exposure and its effect on chlorophyll and protein concentrations. These plants were treated with different concentrations of Cr under repeated exposure in controlled laboratory conditions to assess the maximum metal accumulationpotential. The plants of V. spiralis accumulated significantly high amount of Cr under laboratory conditions incomparison to N. indica and A. sessilis. The maximumaccumulation of 1378, 458 and 201 g g-1 dw Cr was found in the leaves of V. spiralis, N. indica and A. sessilis, respectively at 8 mg L-1 after 9 day of Cr exposure. These plants have shown a decrease in chlorophyll andprotein concentrations with increase in Cr concentrations. In view of high accumulation of Cr in V. spiralis, the plantswere treated with different concentrations of tannery effluent collected from Common Effluent Treatment Plant, Unnao (UP). Theplants of V. spiralis treated with 100% tannery wastewatershowed the maximum accumulation (57.5 g g-1 dw) of Cr in the roots after 10 days of exposure. The plants were foundeffective in removing Cr from solution and tannery effluent.  相似文献   

19.
一起河流砷污染事故的处置与监测分析   总被引:2,自引:1,他引:1  
介绍了大沙河砷污染事故的处置和监测分析。多介质排查监测摸清了污染的范围和程度,为治理工作提供了科学依据,污染治理措施有效控制了污染的扩散;监测数据表明,治理措施将水中砷污染物沉降至河床使污染水质达标排放。吸附了大量砷化合物的底泥被清理并进一步处置,多介质跟踪监测应持续进行直至不存在潜在危害。  相似文献   

20.
日本核泄漏事故引发的核危机为人类安全和平地利用核能又一次敲响了警钟.核事故应急工作作为减小核电站危害环境和公众安全的最后屏障,将起到重要的作用,必须做好相关的准备和响应工作.核应急辐射环境监测工作是核应急工作的重要组成部分,在对核应急辐射环境监测进行准备和响应时主要遵循实用性、适用性和适度性并兼顾常规和应急监测的“平战...  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