宝鸡市街尘重金属元素含量及其环境风险分析

分析了宝鸡市街尘中重金属元素的含量,结果表明:宝鸡市街尘中Cu、Pb、Zn、Cr、Cd、As和Hg的平均含量分别为123.2、408.4、715.1、126.7、5.5、19.8和1.1μg g-1。在工业区、交通区及商业区,除Cr和As略微高于陕西省土壤元素背景值(1.6~2.2倍),其他重金属元素均远远高于陕西省土壤元素背景值(5~64倍)。不同功能分区街尘中重金属元素含量存在显著差异,Hg在交通区含量最高,其他重金属元素均在工业区最高。地累积污染指数法的评价结果表明,宝鸡市街尘中除Cr和As的污染较轻外,其他重金属元素的污染均比较严重,尤其是Cu和Pb在工业区尤为突出。潜在生态风险指数法的评价结果表明,宝鸡市街尘中重金属元素的污染水平和生态危害达到了严重程度,其中,Cr和As属于中等污染,其他重金属元素达到了重度以上污染,Cu、Zn、Cr、As和Pb属于中等潜在生态危害,Hg和Cd达到严重潜在生态危害。     

淮南城区小学校园石楠叶面尘重金属污染特征及健康风险评价

叶面尘能够反映一定区域及时间内近地面大气颗粒物污染情况,可以模拟儿童在特定区域的灰尘暴露情况。以典型煤矿资源型城市淮南城区小学校园中石楠叶面尘及地表灰尘为研究对象,对比分析了其重金属含量、污染特征及来源的差异,并对叶面尘中重金属含量进行健康风险评价。结果表明:叶面尘重金属污染程度为ZnPbAsCuNiCoCr,其中Zn和Pb为中度污染,As和Cu为轻度-中度污染;地表灰尘中重金属污染程度为ZnPbCrCuNiCoAs,其中Zn为中度—强度污染,Pb为中度污染,Cr和Cu为轻度—中度污染。校园地表灰尘中重金属含量一般高于叶面尘。叶面尘主要来源于工业、交通排放、煤炭燃烧,还可能来自于二次扬尘和土壤母质。地表灰尘的来源主要为交通排放,其次是建筑物及公共设施磨损和土壤母质。手-口摄入是儿童灰尘重金属暴露的主要途径,重金属非致癌风险大小为PbAsCrCuZnCoNi,均不构成健康威胁,As、Co、Cr和Ni致癌风险均低于风险阈值,不存在致癌风险。     

三峡库区典型流域水质时空特征及污染防控策略

为了解三峡库区典型小流域不同土地利用类型下水质的变化特征,于2015-2020年对三峡库区长坪小流域开展水质监测,对不同土地利用类型下水体中的总氮（Total Nitrogen,TN）、硝态氮（NO3--N）、氨氮（NH4+-N）、总磷（Total Phosphorus,TP）、可溶态总磷（Dissolved Total Phosphorus,DTP）和颗粒态总磷（Particulate Phosphorus,PP）浓度的时空变化规律进行研究,识别流域内主要氮磷污染源,从而提出针对性的污染防控策略。结果表明：1）不同土地利用类型氮磷输出浓度从大到小依次为村庄、坡耕地、林地和水库,其TN平均浓度分别为8.29、2.88、1.57和1.43 mg/L,TP平均浓度分别为0.25、0.13、0.09和0.07 mg/L。2）不同土地利用类型的水质在汛期和非汛期存在差异,村庄氮磷输出浓度为非汛期高于汛期,坡耕地、林地和水库则表现为汛期高于非汛期。3）内梅罗综合污染指数评价结果表明林地和水库的污染程度均为清洁水平,坡耕地污染程度为轻污染水平,村庄受散养生猪数量的影响,污染程度从污染水平转变为重污染水平。4）长坪小流域TN和TP年输出负荷总量分别为4 278.59和364.93 kg/a。畜禽养殖源是小流域氮磷最主要的污染源,其TN和TP的输出负荷分别占流域总负荷的45.69%和71.77%。坡耕地的TN和TP单位面积污染负荷分别是村庄的7.58%和1.79%,与村庄相比,坡耕地具有显著的低污染特征,因此,以坡耕地消纳村庄污水和畜禽粪便,可促进流域内粪污的就地消纳,达到多源共治的效果。基于小流域不同土地利用类型的水质特征和生态系统服务功能,将流域划分为林草水源涵养区、村庄污染控制区和坡耕地水土保持区,并进行分区协同防控,促进流域农业面源污染系统高效治理。     

重庆市主城区街道地表物中重金属的污染特征

分析了重庆市主城区街道地表物的基本性质及As、Cd、Cr、Cu、Hg，Ni、Pb，Zn等元索的全置、模拟酸雨（pH4．5）的浸出量。结果表明：各功能区中街道地表物的自然组成均以中等粒径的为主；就元素而言，粒径越细对重金属的贡献率越高；就功能区而言．细粒径与中等粒径的颗粒对重金属贡献率较为接近。街道地表物呈碱性，有潜在的有机物污染。重庆市主城区街道地表物重金属元素含量有较大的差异，受人为活动干扰严重的重金属种类为Cr、Cd、Hg、Cu。内梅罗指数评价结果显示除Ni外，其他元素均有不同程度的污染，各功能区均受到重金属的严重污染。重庆市主城区街道地表物中的重金属只与其中的磷素含量显著正相关。     

淮南市石楠叶片重金属分布特征、来源及对大气污染的指示作用

以典型绿化树种石楠叶片为研究对象,采集了淮南市区6个不同功能区种植的石楠叶片,分析石楠叶片中Cr、Cu、Ni、Pb、Zn的分布特征、来源及对大气污染的指示作用。结果表明:淮南市商业交通区叶片中Pb、Zn平均浓度显著大于公园绿地(P0.05),分别是公园绿地的2.95,1.78倍;煤炭运输区叶片中Cu平均浓度显著大于居住区(P0.05)和公园绿地(P0.05),其分别是居住区和公园绿地的2.30,2.81倍,而叶片中Ni和Cr在各功能区的差异无统计学意义。石楠叶片中Pb、Zn主要来自交通排放,Cu主要来自于煤炭开采、燃煤发电以及交通运输,Ni和Cr主要来自自然源。叶片中Cu、Pb、Zn浓度与叶面尘中Cu、Pb、Zn总量呈显著正相关,说明石楠叶片中Cu、Pb、Zn浓度受到叶面尘中Cu、Pb、Zn总量的显著影响。石楠叶片中Cu、Pb、Zn主要是从大气中吸收,而Ni和Cr主要是从土壤中吸收,利用石楠叶片对大气中Cu、Pb、Zn的监测可以取得良好的效果。     

北运河下游不同土地利用非点源污染负荷估算

选取我国北方地区以圩区为主要形式的北运河下游农业灌溉区——天津武清区和北辰区作为研究对象,针对不同土地利用类型进行降雨径流污染物浓度监测,采用美国土壤通用流失方程（USLE）、降雨径流模型（SCS-CN）、综合径流系数法等,结合GIS技术,分别估算了透水地面和不透水地面的氮磷负荷量。结果表明,非点源污染总氮、总磷的年负荷量分别为2865.04t.a-1和101.22t.a-1,不透水地面所产生的TN、TP负荷量分别占研究区污染负荷总量的81%和67%,透水地面所产生的TN、TP负荷量分别占研究区污染负荷总量的19%和33%（且污染物形态以溶解态为主,分别达到了81%和74%）。对于不同土地利用类型,总氮流失主要来源于村庄（贡献率为49%）、城镇（贡献率为17%）和耕地（贡献率为16%）,而总磷主要来源于村庄（贡献率为31%）、耕地（贡献率为23%）和城镇（贡献率为19%）。从产污强度来看,城镇用地是最高的,是其他土地利用类型的10倍以上。     

不同污染方式下铅对茶园土壤氮素转化及其相关微生物和酶活性的影响

为探讨不同污染方式的Pb对茶园土壤氮素转化的影响，采用盆栽试验对累积和一次性添加不同浓度Pb条件下茶园土壤中氮素含量、相关微生物和酶活性进行了研究。结果表明：累积污染处理的土壤中Pb全量和有效态含量高于一次污染处理。Pb污染对土壤、茶苗植株的氮含量影响表现为：增加土壤中全氮和¹⁵N含量，减少茶苗地上部全氮和¹⁵N含量。添加Pb浓度为900 mg/kg时，累积污染处理促进根系全氮和¹⁵N含量，一次污染则显著抑制；累积污染处理的茶苗根和地上部中的氮含量显著高于一次污染(P<0.05)。Pb污染对氮循环相关微生物的影响表现为：氨化细菌、自生固氮菌、亚硝酸细菌和硝酸细菌的数量减少，反硝化细菌的数量增加。Pb的不同污染方式对茶园土壤与氮循环相关微生物数量的影响不显著(P>0.05)。Pb污染抑制脲酶、亚硝化还原酶和硝酸还原酶活性，对蛋白酶活性存在“低促高抑”现象；高浓度Pb(900 mg/kg)污染时，累积处理显著增加土壤羟胺还原酶活性，一次处理则显著抑制。两种污染方式对土壤脲酶、硝酸还原酶和羟胺还原酶活性的影响因Pb...     

红透山铜尾矿重金属分布及其对土壤重金属污染的影响

通过对红透山铜尾矿重金属分布及尾矿区和农田区土壤重金属污染状况进行研究,结果显示:尾矿中四种重金属Cu、Zn、Pb、Cd均出现不同程度的淋滤-富集现象,对周围土壤存在较大的环境威胁。尾矿区土壤综合污染指数16.27,达重污染程度;周围农田土壤为轻度污染,综合污染指数1.29。四种重金属的污染状况分别为:Cd、Cu为重度污染,Zn为轻度污染,Pb为安全级别。     

西安市区不同绿化植物的滞尘效应季节变化研究

以西安市区乔木(山槐)、灌木(丁香)、草本(马蔺)3种植物为试材,研究比较了滞尘量的差异及蒙尘后的生理响应。结果表明:不同绿化植物的滞尘能力差异显著(p0.05),3种植物平均单位面积滞尘量大小顺序依次为:乔木灌木草本;春季和夏季不同绿化植物叶面滞尘量达到饱和时间约为12d,秋季和冬季不同绿化植物叶面滞尘量达到饱和时间约为9d,并且3种植物叶片平均滞尘量依次表现为夏季春季秋季冬季;对叶面尘粒径分析表明,叶面尘中滞留的颗粒物中大多数是TSP(悬浮颗粒物),同时对PM10和PM2.5均有一定量的吸收,降尘物中PM2.5,PM10和TSP相对含量均以乔木最高,灌木和草本较低,其中PM2.5和PM10在乔木、灌木和草本均达到显著差异水平(p0.05),而3种植物TSP差异并不显著(p0.05);随着叶片蒙尘时间的延长,相对含水量出现先下降后上升的趋势,比叶重和脯氨酸含量则呈现先增加后降低趋势,并且3种植物叶片秋季和冬季相对含水量、比叶重和脯氨酸含量均高于春季和夏季。相关性分析表明,3种植物滞尘能力与车流量呈极显著正相关(p0.01)。     

南宁市典型园林植物滞尘效应及生理特性研究

以南宁市典型园林植物（樟树、桂花、冬青、杜鹃）为试材,连续3 a研究和比较了南宁市典型园林植物滞尘效应及生理特性,并探讨了典型园林植物滞尘量及滞尘能力大小。结果表明:南宁市不同典型植物滞尘效应存在显著差异（p < 0.05）,滞尘效应大小依次表现为樟树 > 冬青 > 桂花 > 杜鹃;季节变化对植物的滞尘效应影响显著,春、冬两季滞尘量较大,而夏、秋两季滞尘量较小,相同季节基本表现为樟树 > 冬青 > 桂花 > 杜鹃;南宁市典型园林植物降尘粒径主要分布在2.5～100 μm,叶面降尘中颗粒物粒径集中分布在100 μm以下（占99%以上）;比叶重（x）与叶片滞尘能力（y）之间的幂函数关系最佳（p < 0.001）,即比叶重较大的植物滞尘能力则较大;南宁市典型园林植物叶片保护酶（SOD,POD,CAT）和非保护酶（PAL,PPO）活性均表现为樟树 > 冬青 > 桂花 > 杜鹃,与植物滞尘能力变化趋势相一致,叶绿素a、叶绿素b、可溶性蛋白和可溶性糖呈现出一致的变化规律,均表现为樟树 > 冬青 > 桂花 > 杜鹃;相关性分析表明南宁市典型园林植物滞尘量与叶片酶活性基本呈显著或极显著正相关。     

上海市区街道灰尘重金属污染研究

对上海市区街道灰尘重金属的分布特征、赋存形态及其生物有效性进行了研究,结果表明,市区街道灰尘中Pb、Cu、Ni和Zn的平均含量分别为264、182、86和673 mg kg-1,远高于上海市土壤环境背景值;重金属含量空间分布差异较大,Cu、Pb和Zn污染中心区主要位于商业区和内环线附近,Ni污染中心区主要位于外环线附近;市区街道灰尘中Pb主要以铁锰氧化物结合态存在,Cu主要以有机物结合态存在,Ni主要以残渣态和铁锰氧化物结合态存在,Zn主要以残渣态存在;其生物有效性表现为:Ni≈Pb>Zn>Cu。     

First Study of Anthropogenic Platinum Group Elements in Roadside Top-Soils in Athens, Greece

Concentrations of Pt and Pd in roadside top-soil samples, collected in May 2003, at four types of sites (urban, suburban, rural and highway) in the greater Athens area as well as concentrations of Pb, Cu, Zn, Fe and Ca, were determined. Our results show high concentrations of “classic” (Pb, Cu, Zn) and “new” (Pt, Pd) traffic related elements in top-soils on a highway and a representative urban street in Athens. In the highway samples, the average concentrations of Pt and Pd were 141.1 and 125.9 ng/g respectively, while in the urban street samples they were 35% lower. In the samples of the rural and suburban roads the Pt and Pd levels were very low 2.0 and 1.4 ng/g respectively. These data show an increased accumulation of Pt and Pd in top-soils during the last decade as a result of the gradual increase in the use of vehicles with catalytic converters. The Pt:Pd ratios (average: 1.2) were consistent with known catalytic converters composition (1–2.5), suggesting that the common source of these metals is catalytic converters. The levels of the traffic related elements in suburban and rural roads were very low, suggesting the negligible impact from emission sources. Principal component, biplot and cluster analysis discriminated the traffic related metals from Fe, Mn and Ca, which are abundant in soils, related mainly to the soil parent materials.     

Heavy metals in street and house dust in Bahrain

A total of 106 street and household dusts have been sampled throughout Bahrain and analyzed for Pb, Zn, Cd, Ni and Cr using the atomic absorption spectrophotometric method. The sampling sites were divided into seven categories, including the control site. Results showed that dust samples contained significant levels of the metals studied compared with the control values. The mean values for Pb, Zn, Cd, Ni and Cr in street dust were 697.2, 151.8, 72.0, 125.6 and 144.4 μg g^?1 respectively, whereas for household dust they were 360.0, 64.4, 37.0, 110.2 and 144.7 μg g^?1. These values suggest that motor vehicles form a major source of these metals in dust samples. The values of heavy metals in dust samples in this study were compared with values found in other investigations in various countries. With respect to Ni, elevated concentration could be attributed to smoke from the burning of Kuwait oil fields. Also correlations between metal levels in dust samples for all the metals were investigated. Our results show that heavy metal levels in various sites in Bahrain are similar, which indicate that Bahrain can be considered as one big urban center with high population and traffic density.     

Influence of Airborne Pollution on Cd, Zn, Pb, Cu, and Al Accumulation and Physiological Parameters of Plant Leaves in Antakya (Turkey)

In this study, the effects of industrial and urban pollution on Pb, Al, Cd, Cu, and Zn accumulation, peroxidase activity, and pigment and protein contents were investigated in shrub and tree leaves in Antakya, Turkey. We determined that industrial and traffic activities produce the most plant-incorporated air pollutants in Antakya City. Cu and Al amounts were high in plants in the urban street location and Cd, Pb, and Zn amounts where high for all plants in the industrial site. Acer negundo L. showed maximum Pb and Zn accumulation at the industrial site and Al accumulation for the urban street site. Higher Cd and Cu amounts were detected in Platanus orientalis L. and Nerium oleander L. in the industrial and urban street sites, respectively. Compared to the control site, decreases in pigment and total soluble protein contents and increases in peroxidase enzyme activity were more evident in industrial and urban street sites. Our results indicated that industry and urban air pollution is high in Antakya City and Pb pollution was at an especially alarming level for vegetation and human health.     

Evaluating baseline data for trace elements,pH, organic matter content,and bulk density in agricultural soils in Nigeria

Agricultural soil samples were collected about 1 km apart over 21 km from 32 tilled/cultivated plots of yam, rice, and cassava in urban, rural, and the derelict Enyibga lead-zinc mine (EM) in the Abakaliki area, Nigeria during the rainy season in September, 1992. In the derelict mine, mean elemental contents increased in the order Cd < Ni < Cu < Mn < Pb < Zn; while in the urban, rural, and all soils combined, the order increased as follows: Cd < Cu < Ni < Pb < Zn < Mn. The overall mean distribution of all soils shows Mn and Zn to approach and exceed toxic levels, respectively. In all soils, the total mean concentrations of Cu and Ni are well below toxic levels. The Abakaliki area is less likely to be subjected to Cd-contaminated soils. Pb was excessively high at EM and, moderately high at Mgbowo Street in the urban area, but very less so in the rural areas. The rural agricultural areas of Agbaja, Nkwaegu, and Amaegu, including the isolated Ezza Road as well as the peripheral Expressway had relatively lower levels of heavy metals, pH and organic matter content than the urban conglomeration of Mile 50, Mgbowo Street, and Azuiyiokwu including the derelict mining village of Enyigba and EM; except that Ezza Road had pH and organic matter as high as the densely populated urban cultivated areas. The relationship between bulk density and organic matter was highly dependent on pH.     

乡村振兴战略下农村环境协同治理关键因素识别研究

农村环境治理体系创新和治理路径有效是党的十九大全面部署实施乡村振兴重大战略中核心问题之一。现有关于农村环境问题研究大多是对乡村环境治理模式及多元治理模式中社会资本因素探讨,缺乏多元治理模式中环境治理失灵的实证研究。本研究首先基于利益相关理论,从政府、企业、城市、村民、环保组织、科研院校等不同主体的利益诉求和行为导向定性分析了农村环境目前现实困境,调研梳理出农村环境协同治理的影响因素指标体系;其次为降低决策试验与实验室评估法（DEMATEL）模型中专家打分建立关联矩阵的主观性,引入灰数理论,基于Grey-DEMATEL定量识别影响泉州市农村环境协同治理的原因、结果和综合影响因素,以及研究因素之间的关系和相互影响程度。结果表明：地方保护主义、城市发展汲取农村资源是农村环境协同治理的根本制约因素,忽视农村环保技术有别、重视事前环保技术研发而忽视之后的应用和改进是起关键驱动作用的原因因素;城市污染企业为转嫁排污成本转入偏远农村、农村承载城市发展中一些污染转移是直接障碍因素,是短期内有效改善农村环境治理困境的结果因素;农村基本公共卫生设施建设的资金投入有限是最活跃的影响因素,容易影响其他因素,也容易受其他因素影响,是农村环境协同治理实施的核心因素。最后根据各因素之间的因果关系和综合影响程度分析结果,厘清农村环境治理行动中政府、企业、城市、村民、环保组织、科研院校等不同利益相关者主体之间的博弈关系,明确农村环境治理中各个利益相关者的角色定位,提出泉州市农村环境协同治理的长短期和重点措施等建议,为乡村振兴战略部署中创设利益均衡的农村环境多元协同治理的有效途径提供参考。     

Organic compounds and heavy metals in the atmosphere of the city of Caracas,Venezuela — I: Atmospheric particles

Aliphatic and aromatic hydrocarbons, fatty acids and heavy metals (Pb, Cu, Ni, Zn, Fe and Cd) were analyzed in atmospheric particulate matter in the city of Caracas, Venezuela. Samples were taken from 6 stations within the metropolitan area of Caracas, characterized as industrial (one), urban (two), suburban (two) and rural (one). In addition, the concentration and composition of the organic compounds was monitored over a 5 month period at an urban site to determine seasonal and temporal variabilities. In general terms, the concentrations of pollutants decreased from industrial and urban sites to suburban to rural. A similar trend was observed for preliminary toxicity tests carried out on the particulate extracts. The concentration levels of most of the pollutants were high for the industrial and urban sites, and comparable with those of other major cities worldwide.     

Temporal Variability of Metal Contamination in Urban Road-deposited Sediment in Manchester, UK: Implications for Urban Pollution Monitoring

An important component of monitoring pollution of urban road-deposited sediment (RDS) is an understanding of the temporal variability in its composition and physical characteristics. This study set out to determine what the monthly variability in metal concentrations, organic matter content, grain-size and grain-size fraction metal-loadings are in inner city sites in Manchester, northwest England. The results show that there is significant temporal variability in metal (Pb, Zn, Fe, Mn) concentration in RDS from inner city Manchester. There was no significant temporal variability in grain-size characteristics or organic matter content, indicting that these metal variations were the result of variation in sources and accumulation processes. Pb and Zn displayed local variability, suggesting local controls on variability, whereas Fe and Mn displayed consistent variability across all sites, suggesting a common, larger-scale control on variability. The finest grain-size fraction (<63 μm) contained the highest Pb, Cu and Zn concentrations, but for the case of Fe and Mn, the coarser fractions (>300 μm) commonly contained the highest concentrations, again suggesting differing controls. For all metals, due to the weight percent dominance of the coarser fractions, the dominant loading of metals is in the coarser fractions. This has implications on management strategies, via street sweeping and the subsequent waste disposal, and on the modelling of the input of RDS and associated metals into surface waterways. The recognition of significant temporal variability of metal concentrations in RDS, independent of grain-size changes, implies that the monitoring of urban road sediment pollution will require not just consideration of spatial variability, but the design of schemes that will capture temporal variability also.     

Heavy metals in the lichen Caloplaca aurantia from urban,suburban and rural regions in Israel (a comparative study)

The content of eight heavy metals: Mn, Zn, Fe, Pb, Ni, Cu, Cr and Cd in the lichen Caloplaca aurantia growing on roof-tiles in urban, suburban and rural settlements in Israel has been evaluated. The data obtained and their statistical analysis indicated the following: (1) The content of all the above listed metals was generally higher in the lichen growing in ‘town’ than in ‘village’ areas; among these metals Ni and Zn were found most suitable for the distinction between ‘town’ and ‘village’ settlements. (2) Comparisons of the coefficient of variation of metal content values in ‘town’ versus ‘village’ furnished indications on the dispersion capacity of the metal particles. (3) Correlation analysis among the metals in ‘town’ and ‘village’ resulted in suggestive information on the emission sources. (4) Leaching tests indicated the tenacity of metal retainment and incorporation efficiency into the lichen tissue. Lichen species like C. aurantia, which grow both in ‘clean’ and metal contaminated areas are suggested as comparative monitors and for assessing periodical changes in metal output and concentrations.