重庆市清水溪底泥中镉污染的潜在生态风险评价

采用地累积指数和Hakanson潜在生态风险指数法,通过分析清水溪18个采样点底泥中典型重金属镉的含量,定量确定了清水溪底泥中重金属镉的污染程度和潜在生态风险程度。结果表明,清水溪流域镉污染比较严重,上游比下游污染严重,而且在新桥到高滩岩段受到重金属镉的中强度污染,对周围环境存在极高的镉生态风险。在清水溪干流上采样点底泥中镉的质量浓度范围在0.38~1.48mg/kg之间,平均值0.88mg/kg,各支流底泥中镉的质量浓度范围为0.51~1.08mg/kg。对于清水溪各支流镉的污染程度与潜在生态风险程度由高到低的排序为杨家沟>金竹沟>芭蕉沟>关井沟>石碾盘沟。     

火焰原子吸收光谱法测定底泥中铜铅镍锌镉铬的10种消解方法的比较

湖泊底泥中重金属含量的多寡对水产养殖业的影响以及其底泥能否作为农田肥料都至关重要。目前有关底泥中重金属的测定,原子吸收光谱法是较理想的一种方法。由于对底泥样品所用的前处理方法不同,有时会使测定结果有明显的差异。为此,今对常用的10种消解法[1-6]进行全面、系统的试验比较,供参考。1　试验1 1　主要仪器与试剂AA6800火焰原子吸收光谱仪,岛津;铜、铅、镍、锌、镉、铬单元素空心阴极灯,上海电光器件公司;混合金属标准溶液:铜、铅、镍各为25 0mg/L,锌、铬各为10 0mg/L,镉2 50mg/L;所用试剂除过氧化氢为分析纯外,其余均为优级…     

TCLP法对天津市农田重金属生态风险评价

TCLP法是用缓冲剂提取重金属的一种方法,该法评价重金属生态风险在美国已开展多年。利用TCLP法对天津市某农田土壤重金属进行生态风险评价,结果表明,在采集的23个样品中有效态铜、铅、锌、镉的含量范围为1.13~5.26、2.11~5.22、2.60~30.6、1.09×10-3~77.9×10-3mg/kg,普遍低于铜、铅、锌、镉在土壤中的总量(22.1~66.8、21.2~50.6、56.8~445、0.04~0.20 mg/kg)。镉的TCLP有效态与总量的差别最大。锌、铅存在轻微污染,污染率分别为21.7%、4.3%。     

攀西区域涉重金属典型企业周边环境特征及潜在生态风险

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。     

典型城市工业区TSP中重金属污染研究

以徐州市北郊工业区作为研究对象,探讨工业型城市大气总悬浮颗粒物中重金属元素的时空分布特征。监测结果表明,该区大气TSP中重金属污染较为严重,单个样品中重金属铅、锌、镉、铬、铜和锰的最高含量分别达350.9、1037.9、5.5、16.3、17.8、238.5mg/kg;元素浓度呈秋冬季偏高,夏秋季偏低的趋势;空间分布充分体现了与污染源地域分布的一致性。     

三峡库区重庆段淹没区土壤重金属分布及评价

三峡库区重庆段淹没区土壤重金属含量均低于国家土壤环境标准三级,其中铜含量范围为10.7~80.2mg/kg,均值为37.0 mg/kg;铅含量范围为14.6~51.8mg/kg,均值为29.3mg/kg;锌含量范围为47.5~93.3mg/kg,均值为72.7mg/kg;镉含量范围为0.084~0.765mg/kg,均值为0.321mg/kg;汞含量范围为0.032~0.204mg/kg,均值为0.059mg/kg;砷含量范围为4.63~12.7mg/kg,均值为8.65mg/kg。三峡库区淹没区土壤主要受镉铜污染和铅镉污染。     

如东滩涂近岸海域沉积物重金属分布特征及风险评价

基于2017和2019年如东滩涂近岸海域沉积物重金属调查数据,探讨该海域沉积物重金属的分布特征,通过重金属与环境因子的相关性分析,研究影响重金属分布的控制因素.采用地累积指数法和潜在生态风险指数法评估其污染程度和潜在生态风险.结果表明,铜(Cu)、锌(Zn)、铅(Pb)、铬(Cr)、镉(Cd)、汞(Hg)、砷(As)平...     

南通市某钢丝绳行业集中区降尘中重金属污染状况评价

针对南通市钢丝绳行业集中区重金属污染问题,分析降尘中的铅、镉、铬、铜、镍、铁、锌、锰等重金属含量,并采用污染指数法和地累积指数法对降尘中重金属污染状况进行评价。结果表明,该集中区降尘中重金属污染程度依次为Zn>Pb>Cd>Cu>Fe>Mn>Ni>Cr,铅、锌为主要污染因子,铅、锌污染级别均处于重污染级别。     

揭西不同土地利用类型土壤重金属污染特征及风险评价

监测分析了以揭西县林地、农业用地和建设用地的331个土壤样品中的重金属含量,运用潜在生态风险指数法、健康风险指数法以及克里金插值法等对镍、锌、汞、砷、铜、镉、铅和铬的潜在生态风险和潜在健康风险进行研究。结果表明：汞超出《土壤破坏质量 农用地土壤污染风险管控标准》风险筛选值,存在一定风险。研究区具有轻微潜在生态风险,汞和镉是主要生态风险因子,高值区主要分布在建设用地,综合潜在生态风险高值区主要分布在建设用地。成人和儿童的单项非致癌风险指数总和（HQ_总）和总非致癌风险指数（HI）均<1,非致癌风险在可接受范围内。铬、砷和铅是主要非致癌贡献因子。砷对成人和儿童具有较高的致癌风险,是主要致癌风险因子。不同土地利用类型下成人和儿童总致癌风险指数（TCR）依次为农业用地>林地>建设用地。单项致癌风险指数总和（CR_总）均为砷>镉>铬。     

辽宁绥中海域海水和表层沉积物中重金属污染评价

根据2009年10月的调查数据对辽宁绥中海域海水和表层沉积物中的重金属(砷、汞、铜、铅、锌和镉)进行了研究。用单因子指数评价法对海水中的重金属进行了评价,结果表明,海水中的Zn、Hg含量均超过《海水水质标准》(GB3097-1997)中Ⅰ类海水水质标准。采用《海洋沉积物质量》(GB 18668-2002)Ⅰ类海洋沉积物质量标准评价,表层沉积物中的As超标一倍以上。采用瑞典科学家Hkanson的潜在生态危害指数法进行评价,生态危害程度As>Hg>Cd>Cu>Zn>Pb。     

Topsoil and Housedust Metal Concentrations in the Vicinity of a Lead Battery Manufacturing Plant

The aim of the study was to determine the extent of heavy metal pollution in the vicinity of a lead battery manufacturing plant in the Czech Republic, both in the general environment and within homes. Topsoils (0–5 cm) were sampled from 100 sites along 4 transects which crossed the battery factory, the town centre and outlying rural areas. Housedust samples were collected from 15 plant-workers' homes and 15 non plant-workers' homes located at various distances from the factory. Samples were analysed for levels of Pb, Zn, Cd, Cu, As and Sb, using ICP-AES. Soil concentrations of Pb, Cd, As and Sb peaked at the perimeter fence of the battery factory with Pb levels of up to 12 650 g g> ^-1. Concentrations of these metals decreased exponentially within 500 m of the plant. Whilst the battery factory does appear to be a source of all the metals with the exception of Zn, emissions do not appear to be transported to any great extent over distances of more than 0.5 km. Topsoil and housedust concentrations of Pb, Zn, Cd, Cu, As and Sb in the general Mlada Boleslav area do not appear to be significantly different from those recorded in a large scale survey of urban soils in the United Kingdom. A comparison of housedust Pb concentrations in homes of plant workers and non-plant workers suggests that there may be a small input of Pb into the home environment by battery plant employees.     

An Overview of Contaminant-Related Issues Identified by Monitoring in San Francisco Bay

The San Francisco Estuary Regional Monitoring Program for Trace Substances (RMP) began in 1993 and is sponsored by 74 local, state, and federal agencies and companies through their discharge or Bay use permits. The RMP monitors water, sediment, toxicity, and bivalve bioaccumulation at 25 sites in the Bay that are considered to represent "background" conditions. Several major environmental issues have been identified by the RMP. Polychlorinated biphenyls and mercury were often above water quality guidelines, and often occurred in fish tissues above U.S. Environmental Protection Agency (U.S. EPA) screening values. Concentrations do not appear to be decreasing, suggesting continuing inputs. Episodes of aquatic toxicity often occurred following runoff events that transport contaminants into the Bay from urbanized and agricultural portions of the watershed. Sediment toxicity occurred throughout the Bay, and has been correlated with concentrations of specific contaminants (chlordanes, polynuclear aromatic hydrocarbons) at some locations; mixtures of contaminants were probably also important. Since the RMP does not monitor all ecosystem components, assessments of the overall condition of the Bay cannot be made. However, in terms of contamination, the RMP samples suggest that the South Bay, and North Bay sites are moderately contaminated.     

Biomagnification factors (fish to Osprey eggs from Willamette River,Oregon, U.S.A.) for PCDDs,PCDFs, PCBs and OC pesticides

A migratory population of 78 pairs of Osprey (Pandion haliaetus) nesting along the Willamette River in westernOregon was studied in 1993. The study was designed to determinecontaminant concentrations in eggs, contaminant concentrationsin fish species predominant in the Ospreys diet, andBiomagnification Factors (BMFs) of contaminants from fish specieseaten to Osprey eggs. Ten Osprey eggs and 25 composite samplesof fish (3 species) were used to evaluate organochlorine (OC)pesticides, polychlorinated biphenyls (PCBs), polychlorinateddibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans(PCDFs). Mercury was also analyzed in fish. Geometric meanresidues in Osprey eggs were judged low, e.g., DDE 2.3 g g^-1 wet weight (ww), PCBs 0.69 g g^-1, 2,3,7,8-TCDD 2.3 ng kg^-1, and generally well below known threshold values for adverse effects on productivity, and the population was increasing. Osprey egg residue data presentedby River Mile (RM) are discussed, e.g., higher PCDDs were generally found immediately downstream of paper mills and eggsfrom the Willamette River had significantly elevated PCBs and PCDDs compared to reference eggs collected nearby in the CascadeMountains. Prey remains at nest sites indicated that the Largescale Sucker (Catostomus macrocheilus) and NorthernPikeminnow (Ptychocheilus oregonensis) accounted for an estimated 90.1% of the biomass in the Osprey diet, and composite samples of these two species were collected from different sampling sites throughout the study area for contaminant analyses. With the large percentage of the fishbiomass in the Osprey diet sampled for contaminants (and fisheaten by Ospreys similar in size to those chemically analyzed),and fish contaminant concentrations weighted by biomass intake, a mean BMF was estimated from fish to Osprey eggs for the largeseries of contaminants. BMFs ranged from no biomagnification(0.42) for 2,3,7,8-TCDF to 174 for OCDD. Our findings for themigratory Osprey were compared to BMFs for the resident HerringGull (Larus argentatus), and differences are discussed. Webelieve a BMF approach provides some basic understanding ofrelationships between contaminant burdens in prey species offish-eating birds and contaminants incorporated into their eggs,and may prove useful in understanding sources of contaminants inmigratory species although additional studies are needed.     

The Draft of the New German Guideline VDI 3782/8 to Model Automobile Exhaust Dispersion

The draft of the German guideline to calculate automobile exhaust dispersion is explained. It contains a two-stage-system: For first quick estimates the guideline contains the simple models MLuS and STREET. In case these models are not applicable or their results shows concentration levels close to the air quality standards, the more complex models PROKAS_V and MISKAM are recommended. PROKAS_V is a Gaussian plume model, MISKAM is a 3-dimensional microscale non hydrostatic flow model for built-up areas with an Eulerian dispersion model. The guideline comprises cases in rural areas without or with few adjacent buildings as well as urban areas with buildings near the roads. The contribution gives information about the models, typical results and some of the problems showing up presently.     

Hydrocarbon Utilization in Yeast Isolates Found to Grow in Association with Petroleum in a Polluted Ultisol of Midwestern Nigeria

The population counts of hydrocarbon-utilising yeasts weremonitored at six sampling stations in the Benin City municipalarea over a four-week period. Although the population countswere relatively constant in each locality, the highest countsoccurred in areas heavily polluted by domestic and industrialeffluents. A total of thirty-five hydrocarbon-degrading yeastswere isolated from soil at the sampling stations usingn-hexadecane as sole carbon source. The isolates were identifiedas belonging to the genera Candida (27 strains), Endomycopsis (4 strains). All the organisms grew on long-chainn-alkane, kerosene, diesel oil and crude oil but failed to growon short-chain n-alkane, aromatic and alicyclic hydrocarbons.Measurement of growth attributes of the isolates usingn-hexadecane, diesel oil and crude oil as substrates showed thatthe Candida species were better utilizers of hydrocarbonsubstrates relative to Endomycopsis and Schizosaccharomyces species.     

火焰原子吸收光谱法测定苏州开发区26种蔬菜中铜锌铁锰镍

用火焰原子吸收光谱法测定了苏州开发区26种蔬菜中的铜、锌、铁、锰和镍的含量。蔬菜样品用硝酸高氯酸混合酸进行消解。4次测定值的相对标准差<5%,加标回收率在92%～107%之间。26种蔬菜中铜、锌、铁、锰、镍的含量基本均在世贸组织规定的范围内。     

Using Multiple Taxonomic Groups to Index the Ecological Condition of Lakes

Biological indicators of communitiestypically reflect a common environmental signalreflecting the general condition of the ecosystem, as well asindividual signals by indicators differentiallysensitive to particular environmental conditions. Wedescribe here a method of integrating and interpretingsuch indicators from 19 New England lakes for fivetaxonomic groups (diatoms, benthos, zooplankton, fish,and birds). Our approach provides a systematicstandardized way to integrate multiple metrics fromdifferent taxonomic groups by addressing four elementscrucial to analyzing data from multiple indicators: covariate control, re-scaling of data, standardizing the sign of responses, and dimensional reduction. We evaluated the biologicalmetrics against individual environmental stressors andagainst multivariate physicochemical metricscharacterizing general anthropogenic stress among thelakes. The method detected a response to variationin the gross environmental condition of the lakes thatwas correlated across taxa and metrics. In addition,a differential response to near shore conditions wasdemonstrated for fish. The success of the approach inthis study lends support to its general application toecological monitoring involving complex data sets.     

Concentrations of Cadmium, Mercury and Selenium in Blood, Liver and Kidney of Common Eider Ducks from the Canadian Arctic

We determined concentrations of selected trace elements inlivers, kidneys and blood samples from common eiders (Somateria mollissima borealis) from the eastern Canadianarctic during 1997 and 1998. Concentrations of totalmercury and organic mercury were generally low in the liversof these birds (less than 6 and 4 g g^–1 dry wt,respectively). Selenium ranged between 11–47 g g^–1 inlivers. Renal cadmium concentrations were among the highestever published for this species (range: 47–281 g g^–1). The regressions of log-transformed concentrations ofthese trace elements in blood samples on those in liver orkidney were significant (all P-values < 0.05) andpositive. However, except for organic mercury (RM ² = 0.83), the co-efficients of determination were low tomoderate (range of R ²: 0.26–0.52), suggesting poorto moderate predictive capability. Furthermore, therelationships between total mercury in blood and liverchanged between 1997 and 1998, suggesting that it would notbe possible to predict consistently, concentrations ofmercury in blood from those in liver based on samples takenin one year. Blood samples can be used to determineconcentrations of these trace elements in common eiders (andprobably other sea duck species as well). The use of bloodsamples is especially warranted when it is undesirable tokill the animal such as when working with rare or endangeredsea duck species or when the objective is to relate traceelement exposure to annual survival rates. However, thepredictive equations developed here should not be used topredict expected concentrations in one type of tissue fromthose in the other.     

Impact of Pollution Caused by Uranium Production on Soil Macrofauna

Thirty years of mining and milling activities of the Priargunsky Mining-Chemical Production Company (South-Eastern Siberia, Russia) have resulted in an enrichment of uranium in adjacent steppe soils by a factor of up to 600. A number of attendant pollutants (thorium, arsenic and heavy metals) also have high concentrations in the soil. To estimate the effects of this pollution on soil-living macroinvertebrates, pitfall trapping and core sampling were applied. The element composition of four beetle species was analysed. Soil macroinvertebrates had 3–37 times lower abundance and biodiversity at the contaminated sites compared with the control. Ground beetle communities at the contaminated sites were reduced compared to the control site. The concentrations of uranium and arsenic in beetles collected at the contaminated sites were 2–41 and 2–26 times higher, respectively, than at the control site. There is strong evidence that the contamination caused by uranium production has severe negative biological effects on important groups of the soil food web.     

Eutrophication and Sedimentation Patterns in Complete Exploitation of Water Resources Scenarios: An Example from Northwestern Semi-arid Mexico

Water requirements to supply human needs lead water stakeholders to store more water during surplus periods to fulfil the demand during – not only – scarcity periods. At the reservoirs, mostly those in semi-arid regions, water level then fluctuates extremely between rises and downward during one single year. Besides of water management implications, changes on physical, chemical and biological dynamics of these drawdown and refilling are little known yet. This paper shows the results, throughout a year, on solids, nutrients (N and P), chlorophyll-a, and sedimentation changes on the dynamics, when the former policy was applied in a reservoir from the semi-arid Northwestern Mexico. Water level sinusoidal trend impinged changes on thermal stratification and mixing, modifying nutrient cycling and primary producer responses. According to nitrogen and phosphorus concentration as well as chlorophyll-a, reservoir was mesotrophic, becoming hypertrophic during drawdown. Nutrient concentrations were high (1.22 ± 0.70 and 0.14 ± 0.12 mg P l⁻¹), increasing phosphorus and lowering N:P significantly throughout the study period, although no intensive agricultural, no urban development, neither industrial activities take place in the watershed. This suggests nutrient recycling complex mechanisms, including nutrient release from the sediment–water interface as the main nutrient pathway when shallowness, at the same time as mineralization, increases. Outflows controlled nitrogen and phosphorus availability on the ecosystem while organic matter depended on river inflows. As on other subtropical aquatic ecosystems, nitrogen limited primary productivity (Spearman correlation R = 0.75) but chlorophyll-a seasonal pattern showed an irregular trend, prompting other no-nutrient related limitants. Shallowness induced a homogeneous temporal pattern on water quality. This observed temporal variability was mainly explained statistically by changes on solids (mineral and organic), chlorophyll-a and flows (62.3%). Annual sedimentation rates of total solids ranged from 11.73 to 16.29 kg m⁻² year⁻¹ with organic matter comprising around 30%. N:P ratio on sedimentation rates were as high as could be expected in a resuspension dominated ecosystem, and spatially inverse related with N:P ratio on bottom sediments. Distance from river inlet into the reservoir reveals a marked spatial heterogeneity on solid and nitrogen sedimentation, showing the system dependence on river inflows and supporting resuspension as the main phosphorus pathway. Accretion rates (2.19 ± 0.40 cm year⁻¹) were not related to hydrological variability but decreased with the distance to the river input. Total sediment accumulation (9,895 tons km⁻² year⁻¹) denotes siltation as other serious environmental problem in reservoirs but possibly not related with operational procedures.