青岛市不同功能区常见绿化植物及土壤汞污染特征

城市植物汞的污染特征,能够反映其生境特性,并能为城市汞污染防治提供科学依据.为了解青岛市植物及土壤汞污染特征,采集了青岛市不同功能区植物包括柏树(Cyparissus)、落叶松(Pinus)、法桐(Platanus)、黄杨(Euonymus)、冬青(Ilex),并同步采集相应表层土壤样品,采用冷原子吸收法测定总汞含量,研究汞的含量及分布.结果表明,不同的植物对汞的吸收累积能力不同,汞含量范围为7.2～95.7 ng·g-1,其中冬青和黄杨对汞的吸收累积能力高于其他植物,分别达到59.79 ng·g-1和51.85 ng·g-1.植物的不同器官对汞的吸收能力不同,一般表现为树茎<树叶.不同功能区植物含汞量有很大的差异,植物在老工业区的汞含量最高,在新经济技术开发区的含量较低.道路两旁的植物中汞含量较高,说明交通是影响植物汞含量的一个重要因素.老工业区土壤汞含量最高于其它功能区,但植物中的汞含量和土壤中的汞含量没有显著的相关性.青岛市表层土壤汞含量低于中国其他城市的汞含量水平.青岛市常见绿化植物只有老工业区为中度污染,其它地区均为轻度污染.     

广州市区植物叶片重金属元素含量及其大气污染评价

文章通过对广州市区植物叶片中重金属元素含量的分析，研究了植物大气环境污染指数，探讨了植物叶片重金属元素含量与城市大气环境污染之间的关系。结果表明，植物叶片中Cu,Pb,Cd,Cr元素污染都较严重，在重污染区这些元素的含量明显高于清洁对照区；用植物污染指数可以综合评价大气环境质量状况；利用植物叶片内的重金属含量变化，为大气污染生物监测和环境质量评价提供了科学依据。     

珠三角某垃圾焚烧厂周边植物叶片汞含量空间格局影响因素影响因素

为研究珠三角某城市生活垃圾焚烧厂周边汞污染空间格局及影响因素,于2014年1月,采集了马占相思、荔枝和芒萁等优势种的叶片样品192份,并同步采集相应表层土壤样品64份,采用冷原子吸收法测定样品总汞含量,并运用ADMS模型对2013年大气汞年均浓度进行模拟,分析了植物叶片汞含量与土壤和大气汞浓度之间的关系。结果表明,植物叶片的汞含量范围为0.0029~0.1741 mg·kg-1,荔枝叶片汞含量最高,为(0.0766±0.0395)mg·kg-1,其次为芒萁((0.0599±0.0370)mg·kg-1)和马占相思((0.0556±0.0396)mg·kg-1)。植物叶片汞含量与土壤汞含量无显著相关性,而受风向和距污染源的距离影响显著,与ADMS模拟的大气年均汞浓度存在显著相关性。研究表明,植物叶片汞含量变化与烟气扩散浓度的空间分异格局基本吻合,叶片对大气中汞的吸收在植物与环境的汞交换中占据主导地位,对叶片的生物监测可以反映城市生活垃圾焚烧厂汞排放对生态环境的实际影响。     

招远市区土壤及常见绿化植物汞污染特征

为查明长期黄金开采冶炼对城市汞污染的影响,以"金都"招远为研究对象,于2011年4月,采集了招远市区常见绿化植物柏树、落叶松、冬青的茎叶样品30份,并同步采集相应表层土壤样品34份。采用冷原子吸收法测定样品总汞含量,分析了土壤的理化性质。结果表明,招远市区表层土壤中汞含量范围为0.002~0.815 mg·kg-1,平均值为0.149 mg·kg-1。土壤汞含量与有机质呈极显著正相关,与p H、粗颗粒比例呈显著正相关关系,而与阳离子交换量、黏粒比例呈显著负相关。不同城市区域相比,处于金矿区污染源下风向、且与矿区距离较近的梦芝区土壤汞含量要显著高于其它区域。常见绿化植物茎叶汞含量范围为0.021~0.782 mg·kg-1,不同植物中的汞含量没有显著差异,但同种植物中茎、叶中汞含量存在极显著正相关。植物中的汞在各城市区域没有显著差异,与土壤汞含量也不存在显著相关性。研究结果显示,招远市区土壤和植物受周边金矿开采和黄金冶炼的影响,存在一定程度汞污染。     

珠江三角洲典型地区蔬菜重金属污染现状研究--以中山市和东莞市为例

以珠江三角洲典型地区中山市与东莞市为研究对象，通过对其大型蔬菜生产基地中10种蔬菜76个样品中重金属元素铬、铅、镉和汞的含量进行分析，初步摸清了珠江三角洲典型地区中山市与东莞市蔬菜中的重金属污染状况，并在不同城市不同蔬菜品种之间的污染程度进行了比较。结果表明，蔬菜中铬、铅、镉、汞的平均含量分别为0．1719、0．0962、0．0257和0.0014mg/kg，其中铬、铅、镉含量超出了国家卫生标准的允许量的蔬菜样品分别有1．3％、13，2％与13．2％；4种重金属在10种蔬菜中的平均残留量由大到小依次为：铬→铅→镉→汞；铅、镉是珠江三角洲典型地区中山市与东莞市蔬菜中的主要污染元素。     

天然石生苔藓汞含量及对大气汞污染的生物指示

采集贵州万山汞矿区6属7种优势种类苔藓84个样品,测定其汞含量,同时现场监测部分苔藓采样点近地表大气汞,定量分析苔藓汞和大气汞质量浓度之间的关系.结果显示,研究区苔藓汞质量浓度范围为0.96—126μg·g~(-1),平均值80±46μg·g~(-1),受触媒生产、废触媒回收等涉汞化工厂生产活动影响显著;苔藓汞与大气汞呈正相关关系,表现为线性拟合相关性系数r=0.93(n=12,P=0.01030),多项式拟合相关性系数r=0.96(n=12,P=0.01169),对数拟合相关性系数r=0.96(n=12,P=0.00469);选择对数拟合方程估算苔藓采样点大气汞浓度,发现拟合得到的大气汞空间分布特征和实测苔藓汞空间分布特征基本一致,从而通过定量/半定量方法证明了可以利用苔藓汞指示大气汞污染,为汞污染场地修复过程中的大气汞污染评价提供了新思路.     

青藏高原林线森林汞的空间分布格局及对大气环境汞污染的指示

汞是引人关注的全球性污染物,偏远地区汞的源汇关系是当前研究的重点.由于其特殊的地理环境与大面积在线监测的不便,青藏高原大气汞的污染特征尚不明确.本研究根据青藏高原季风的传播路径,设置了云南-西藏与四川-西藏两条采样带,通过测定样带上林线森林各个组分的汞含量,来反演大气汞的污染状况.研究结果表明,青藏高原林线区域的冷杉凋落物、树叶树皮与表层土壤的汞含量均表现为越靠近青藏高原腹地,汞浓度越低.特别冷杉凋落物在云南与西藏、四川与西藏的交界区域汞浓度为60—70 ng·g~(-1),而昌都地区汞浓度仅为20—30 ng·g~(-1).此外还发现,凋落物与表层土壤的总汞含量在空间分布上与经度正相关,与纬度负相关.通过综合分析排放清单与大气环流资料,其原因可总结为:越靠近青藏高原腹地,局地源的汞排放与大气环流输送的汞均显著减少,使得大气环境汞含量降低,进而导致植被与土壤汞含量相应下降.本研究表明了凋落物中的总汞含量可作为大气环境汞污染的指示指标,证实了南亚、东南亚及我国的四川盆地与云贵高原是青藏高原大气汞污染的潜在排放源.     

施肥及种植作物对汞污染土壤中微生物生态的修复

以中性紫色土为材料，通过向土壤添加氯化汞的模拟培养试验、施肥试验以及作物栽培试验，研究了汞对土壤中微生物区系和重要微生物生理群繁育的毒害效应。结果表明，向土壤中添加HgCl2，总体上抑制了细菌、真菌、放线菌及氨化细菌的繁育，硝化细菌、自生固氮菌、纤维素降解菌在一定质量分数范围内被汞刺激增长，在另一定质量分数段则被汞抑制。施肥和栽种作物削弱了汞对微生物的毒害，使土壤微生物生态得到一定程度的修复，说明利用农业措施修复汞污染的土壤是可行的。栽种作物时，汞对微生物的抑制效应受到掩蔽，作物产量和植株体内汞含量是汞污染程度的良好指标。以微生物和植物对汞污染的反应，基本一致的HgCl2危害质量分数指标是5mg．kg^-1。     

贵州万山汞矿地区耐汞野生植物研究

在贵州万山地区废弃汞矿堆和矿山附近,受长期高剂量汞暴露的影响经过的自然选择,该地区出现了一些能耐受汞毒性的生态型植物。对汞耐受及汞富集植物的筛选对于汞污染土壤的植物修复具有一定的现实意义。通过对万山梅子溪地区汞污染土壤及汞耐受植物采样调查发现,该区域采样土壤中汞的含量均在50 mg·kg-1以上,达到重度汞污染水平。对该地区野生植物的采样分析发现,蔷薇科植物悬钩子不仅数量较多,单株植物生物量较大,表现出很强的耐汞毒性的能力,而且植株内可以很大程度地富集汞,在其植株中汞的含量可达20 mg·kg-1左右,属于汞富集植物,另外发现野蒿对汞也具有较强的富集能力,其植株中汞的含量可达10 mg·kg-1以上。该类型植物的发现将为植物的汞耐受以及汞富集机理研究提供新的素材,为汞污染土壤的植物修复技术提供新的植物类型,也为进一步开发汞污染土壤处理技术提供了一种可能。     

典型城市人工湿地优势植物汞分布特征

以重庆市4个典型城市人工湿地(观音塘湿地公园、彩云湖国家湿地公园、园博园湿地公园、秀湖湿地公园)为研究对象,分别于2017年3、6、9、12月调查并采集了湿地优势植物样品,分析样品总汞、甲基汞浓度,探讨城市人工湿地中植物汞的时空分布特征.结果表明,调查区域植物汞质量浓度范围为45.29—231.01μg·kg~(-1)(平均值为33.99±8.61μg·kg~(-1)).甲基汞质量浓度范围为45.29—232.01 ng·kg~(-1)(平均值为145.45±48.72 ng·kg~(-1));其中,园博园湿地植物总汞质量浓度最低,观音塘湿地公园植物甲基汞质量浓度均较其他3个湿地公园植物高;在同一湿地中,植物总汞春秋浓度较高,夏季略有降低,冬季最低,而甲基汞浓度先逐渐升高,并在6—9月达到最大值,随后开始下降;植物根部总汞、甲基汞含量高于茎和叶.城市人工湿地植物有一定的汞富集能力,可在一定程度上减轻水体汞污染.     

中国城市土壤重金属污染研究现状及对策

中国城市土壤重金属污染的主要来源是工业“三废”排放，金属采矿和冶炼，家庭燃煤，生活垃圾，汽车尾气排放。重金属在城市土壤中的分布规律表现为城市土壤重金属含量高于郊区，人类活动密集区和交通拥挤区重金属含量较高；人类活动的干扰导致土壤剖面重金属污染特征不明显。应采取预防与治理相结合的措施综合控制土壤重金属污染，并加紧制定我国的城市土壤健康评价标准。     

Environmental geochemistry studies in the area of Idrija mercury mine, Slovenia

Five centuries of mining and processing of mercury ore in the Idrija area have resulted in widespread contamination of different environmental compartments. Environmental impacts on a regional and local scale, caused by atmospheric emissions from the Idrija ore roasting plant, were established in the investigations of mercury spatial distribution in soil and attic dust in 160 km(2) area. Very high values were determined in the Idrijca River valley, and they decrease exponentially with the distance from Idrija. Mercury concentrations in attic dust are higher than in surrounding soils and the attic dust/soil ratio changes with distance. Measurements of mercury in the air confirmed widespread dispersion of mercury and showed highly elevated mercury concentrations around roasting plant and mine ventilation shaft. Beside, systematic monitoring of mercury contents in the stream sediments has demonstrated that huge amounts of mercury are stored in areas where ancient overbank sediments were deposited, and there was no decrease in mercury concentration in active sediments during the last 15 years. Recently, interesting and extremely polluted locations of historical small-scale roasting sites in the Idrija surroundings were discovered. Ongoing geochemical study aims to determine the extreme pollution and significance of these sites for wider contamination of soils and aquatic systems. Presented studies have shown that Hg mining in Idrija caused intense pollution of local and regional environment including the aquatic systems in the Gulf of Trieste, which is seen as the final sink of a major part of the Hg stored in soils and river sediments in the Idrija area.     

Trace metals accumulation in soil irrigated with polluted water and assessment of human health risk from vegetable consumption in Bangladesh

Trace metals accumulation in soil irrigated with polluted water and human health risk from vegetable consumption was assessed based on the data available in the literature on metals pollution of water, soil, sediment and vegetables from the cites of Bangladesh. The quantitative data on metal concentrations, their contamination levels and their pollution sources have not been systematically gathered and studied so far. The data on metal concentrations, sources, contamination levels, sample collection and analytical tools used were collected, compared and discussed. The USEPA-recommended method for health risk assessment was used to estimate human risk from vegetable consumption. Concentrations of metals in water were highly variable, and the mean concentrations of Cd, Cr, Cu and As in water were found to be higher than the FAO irrigation water quality standard. In most cases, mean concentrations of metals in soil were higher than the Bangladesh background value. Based on geoaccumulation index (I _geo) values, soils of Dhaka city are considered as highly contaminated. The I _geo shows Cd, As, Cu, Ni, Pb and Cr contamination of agricultural soils and sediments of the cities all over the Bangladesh. Polluted water irrigation and agrochemicals are identified as dominant sources of metals in agricultural soils. Vegetable contamination by metals poses both non-carcinogenic and carcinogenic risks to the public. Based on the results of the pollution and health risk assessments, Cd, As, Cr, Cu, Pb and Ni are identified as the priority control metals and the Dhaka city is recommended as the priority control city. This study provides quantitative evidence demonstrating the critical need for strengthened wastewater discharge regulations in order to protect residents from heavy metal discharges into the environment.     

Environmental contamination and risk assessment of mercury from a historic mercury mine located in southwestern China

A field survey of mercury pollution in environmental media and human hair samples obtained from residents living in the area surrounding the Chatian mercury mine (CMM) of southwestern China was conducted to evaluate the health risks of mercury to local residents. The results showed that mine waste, and tailings in particular, contained high levels of mercury and that the maximum mercury concentration was 88.50 μg g^?1. Elevated mercury levels were also found in local surface water, paddy soil, and paddy grain, which may cause severe health problems. The mercury concentration of hair samples from the inhabitants of the CMM exceeded 1.0 μg g^?1, which is the limit recommended by the US EPA. Mercury concentrations in paddy soil were positively correlated with mercury concentrations in paddy roots, stalks, and paddy grains, which suggested that paddy soil was the major source of mercury in paddy plant tissue. The average daily dose (ADD) of mercury for local adults and preschool children via oral exposure reached 0.241 and 0.624 μg kg^?1 body weight per day, respectively, which is approaching or exceeds the provisional tolerable daily intake. Among the three oral exposure routes, the greatest contributor to the ADD of mercury was the ingestion of rice grain. Open-stacked mine tailings have resulted in heavy mercury contamination in the surrounding soil, and the depth of appreciable soil mercury concentrations exceeded 100 cm.     

矿粮复合区土壤-作物系统重金属污染风险性评价

为分析矿区污染农田农作物生产的生态安全性,以焦作市中马村矿区的典型农田为例,对矿区农田土壤及植物中Zn、Cr、Cd、Cu和Pb等重金属的质量分数进行了测定,并对重金属污染风险进行了评价。结果表明,根据重金属的单项污染指数,在矿井水污灌农田（F1样地）土壤中Zn和Cd的质量分数达到中度污染水平,Cr的质量分数达到轻微污染水平,Cu和Pb元素质量分数未达到污染水平。在煤矸石污染农田（F2样地）土壤中Zn、Cr和Cd的质量分数达到轻度污染水平,Cu和Pb元素质量分数未达到污染水平。在矿区公路侧农田（F3样地）土壤中各元素质量分数均未达到污染水平。采用潜在生态风险指数法对土壤重金属污染的生态风险进行评价,F1和F2样地综合生态风险指数分别为239．60和178．42,达到中等水平,F3样地土壤达到轻微生态风险水平。采用单项污染指数和综合污染指数法对小麦（Triticumaestivum）籽粒中重金属风险进行评价,在F1和F2样地中,小麦籽粒中Cu质量分数均未达到污染水平,Pb、Cd和Cr质量分数均达到重度污染水平。Zn质量分数在Fl样地中达到轻度污染水平,在F2样地中达到中度污染水平。在F3样地中,小麦籽粒中Cd和Cu质量分数未达到污染水平,Zn质量分数达到轻度污染水平,Pb、Cr质量分数达到重度污染水平。从综合污染指数评价来看,F1、F2和F33个样地小麦籽粒中重金属污染综合指数均达到重度污染水平。评价结果对科学治理矿区污染土壤,确保矿区农田生态安全、粮食生产安全具有重要意义。     

Environmental geochemistry studies in the area of Idrija mercury mine,Slovenia

Five centuries of mining and processing of mercury ore in the Idrija area have resulted in widespread contamination of different environmental compartments. Environmental impacts on a regional and local scale, caused by atmospheric emissions from the Idrija ore roasting plant, were established in the investigations of mercury spatial distribution in soil and attic dust in 160 km² area. Very high values were determined in the Idrijca River valley, and they decrease exponentially with the distance from Idrija. Mercury concentrations in attic dust are higher than in surrounding soils and the attic dust/soil ratio changes with distance. Measurements of mercury in the air confirmed widespread dispersion of mercury and showed highly elevated mercury concentrations around roasting plant and mine ventilation shaft. Beside, systematic monitoring of mercury contents in the stream sediments has demonstrated that huge amounts of mercury are stored in areas where ancient overbank sediments were deposited, and there was no decrease in mercury concentration in active sediments during the last 15 years. Recently, interesting and extremely polluted locations of historical small-scale roasting sites in the Idrija surroundings were discovered. Ongoing geochemical study aims to determine the extreme pollution and significance of these sites for wider contamination of soils and aquatic systems. Presented studies have shown that Hg mining in Idrija caused intense pollution of local and regional environment including the aquatic systems in the Gulf of Trieste, which is seen as the final sink of a major part of the Hg stored in soils and river sediments in the Idrija area.

     

Lead pollution in soils adjacent to homes in Tampa,Florida

In the United States, the study of lead pollution in soil has focused on older cities throughout the industrialised northern tier of states often referred to as the rust belt. Researchers have not studied the magnitude and extent of contamination in the newly developed portions of the sunbelt region of the south. In order to assess the significance of lead pollution in soils in these areas, an analysis of the lead content in 146 soil samples collected at a one km grid throughout residential portions of Tampa, Florida was undertaken. The results reveal that lead contaminated (>500 g g^–1) soil is present in the older portions of the city and near expressways. A comparison of the results with data collected in an older, northern city demonstrates that the magnitude and extent of the contamination in Tampa are less than found in the larger rust belt city. However, the presence of hazardous levels of lead in soil collected in Tampa is evidence that sunbelt cities must address lead pollution in the urban environment.     

Environmental geochemistry studies in the area of Idrija mercury mine,Slovenia

Five centuries of mining and processing of mercury ore in the Idrija area have resulted in widespread contamination of different environmental compartments. Environmental impacts on a regional and local scale, caused by atmospheric emissions from the Idrija ore roasting plant, were established in the investigations of mercury spatial distribution in soil and attic dust in 160 km² area. Very high values were determined in the Idrijca River valley, and they decrease exponentially with the distance from Idrija. Mercury concentrations in attic dust are higher than in surrounding soils and the attic dust/soil ratio changes with distance. Measurements of mercury in the air confirmed widespread dispersion of mercury and showed highly elevated mercury concentrations around roasting plant and mine ventilation shaft. Beside, systematic monitoring of mercury contents in the stream sediments has demonstrated that huge amounts of mercury are stored in areas where ancient overbank sediments were deposited, and there was no decrease in mercury concentration in active sediments during the last 15 years. Recently, interesting and extremely polluted locations of historical small-scale roasting sites in the Idrija surroundings were discovered. Ongoing geochemical study aims to determine the extreme pollution and significance of these sites for wider contamination of soils and aquatic systems. Presented studies have shown that Hg mining in Idrija caused intense pollution of local and regional environment including the aquatic systems in the Gulf of Trieste, which is seen as the final sink of a major part of the Hg stored in soils and river sediments in the Idrija area.     

土壤污染物来源及前沿问题

人类活动对土壤系统的影响日趋严重。土壤污染物主要来自污染的大气沉降，废水和污水灌溉，工业废渣和城市垃圾，以及农药施用等。土壤污染对环境和人体健康造成极大的危害。文章通过计算得出了大气汞沉降和酸沉降在中国的累积沉降量，并通过调查分析中国各项污染物来源的最新资料，详细论述了各主要污染因素对土壤系统的影响。文章阐述了污染物在土壤系统中主要的物理化学行为，主要包括污染物在土壤生态系统中的吸附、迁移和扩散、酸沉降对土壤系统的影响等三个方面。最后回顾了该领域的研究现状和主要的前沿问题，并对进一步的深入研究提出了建议。     

津河水系的修复对天津城市生态环境的影响

针对天津城市生态环境特点和背方城市大气污染现状，探讨了津河水系的修复对改善城市环境质量，丰富城市景观以及修复城市生态环境的重要意义。