贵阳南部近郊蔬菜重金属污染状况及健康风险评估

于贵阳花溪区蔬菜种植基地及零星菜地采集叶菜类、茎菜类和果菜类样品及对应土壤样品,测定土壤与蔬菜样品中Zn、Cd、Pb和Cu含量,分析土壤理化性质、土壤重金属全量、有效态含量与蔬菜中重金属含量之间的关系,通过污染指数和暴露风险健康评估指数分析城郊蔬菜中重金属污染状况以及摄入人群的健康风险。结果表明:部分菜地土壤样品Zn、Cu含量超出农用地土壤污染风险筛选值,超标率分别为8.82%、11.76%;蔬菜中重金属含量主要取决于土壤重金属有效态含量;研究区蔬菜均处于清洁水平,但有8.82%的蔬菜样品Pb处于Ⅱ级警戒值,且均为叶菜;Pb是叶菜类暴露健康风险的主要元素,而Cu是茎菜类与果菜类暴露健康风险的重要元素;蔬菜重金属对儿童和成人的危害指数均小于1.0,表明食用该地区的蔬菜不会对人体健康产生不良影响。     

桂林市表层土壤总汞分布特征研究

为了研究桂林市表层土壤汞污染情况,采集了不同功能区(包括校园区、风景旅游区、交通运输区、居民区、商业区、农业用地区和其他区域)的表层(0~10cm)土壤样品36个,采用硫酸-硝酸混合液浸提、原子荧光方法测定土壤中的总汞。结果表明,桂林市表层土壤的总汞质量浓度在0.136~1.873mg/kg,平均值为0.557mg/kg,中值为0.440mg/kg。各功能区土壤中汞的平均值均超过《土壤环境质量标准》(GB 15618—1995)的一级标准(0.15 mg/kg),以风景旅游区最高,为0.900 mg/kg,其次为商业区,为0.595 mg/kg。进一步对桂林市表层土壤总汞浓度与环境参数的关系进行了研究,结果表明,各采样点土壤的总汞浓度与有机质显著相关,与土壤pH无相关关系。     

贵州遵义松林镍-钼多金属矿区土壤及农作物钒健康风险评价

为研究贵州遵义松林镍(Ni)-钼(Mo)多金属矿区土壤和农作物钒(V)污染情况,采集矿区旱地土、水稻土、森林土和农作物样品进行V含量分析,并分别采用地累积指数法和危险商法进行健康风险评价。结果表明:(1)矿区土壤V平均值为406mg/kg,分别为对照样品V(82mg/kg)和贵州土壤V背景值(139mg/kg)的4.95、2.92倍。其中,旱地土、水稻土和森林土V平均值分别为446、303、470mg/kg,均出现V富集现象。(2)矿区3种类型土壤V污染程度主要集中在轻度污染。水稻土和旱地土的危险商指数(HQ)均小于1,V造成健康风险的可能性较小。(3)6种农作物V为16.25～22.42mg/kg。水稻、玉米、甘薯、白菜和萝卜的HQ分别为13.25、1.44、1.40、6.36和2.57,表明长期食用这5类农作物可能会对人体产生一定的V健康风险,尤其以水稻和白菜的V健康风险最显著。     

福州市主栽蔬菜品种对砷的积累及健康风险

为阐明福州市主要蔬菜基地种植的蔬菜中砷积累特征与食用风险水平,对研究区域内蔬菜和对应土壤中砷含量进行了分析检测,采用Monte-Carlo模型法对蔬菜中砷引起的健康风险进行了评价,并探讨了蔬菜和土壤砷含量之间的相关性及不同品种、不同类别蔬菜之间积累砷的差异。结果表明:研究区内菜地土壤没有明显的砷超标,砷含量均未超出国家土壤二级标准(30 mg·kg~(-1));研究区内蔬菜安全状态很好,不存在明显的健康风险;蔬菜中砷与其对应土壤中砷之间无显著相关性;不同类别的蔬菜之间对于砷的累积存在差异性,蔬菜中砷的富集系数顺序为叶菜类根茎类瓜果类,其中茼蒿的富集系数最大,豌豆和辣椒的最小。     

南京市紫金山土壤中6种重金属的污染特征和污染水平评价

为探究人类活动对南京市紫金山国家森林公园土壤重金属污染的影响,研究了紫金山土壤中6种重金属(Cu、Zn、Pb、Cr、Ni、Mn)的污染特征,并采用单因子指数法和内梅罗综合指数法进行了污染水平评价。结果表明:Cu的质量浓度范围为4.21~249.75mg/kg,平均值为64.08mg/kg;Zn的质量浓度范围为155.26~418.75mg/kg,平均值为212.34mg/kg;Pb的质量浓度范围为112.19~608.91mg/kg,平均值为319.57mg/kg;Cr的质量浓度范围为29.54~201.25mg/kg,平均值为127.36mg/kg;Ni的质量浓度范围为46.64~142.48mg/kg,平均值为76.16mg/kg;Mn的质量浓度范围为182.59~1 634.48mg/kg,平均值为1 008.93mg/kg。总体而言,上层样(0~20cm)的重金属浓度高于下层样(20~40cm),高海拔的重金属浓度低于低海拔的。内梅罗综合指数表明,所有采样点均处于重度污染状态。分析6种重金属的单因子指数发现,主要是因为Pb的单因子指数较大。     

某废弃铅冶炼场地周边蔬菜重金属污染水平及来源解析

于某废弃铅冶炼场地周边菜地采集69份蔬菜样品,通过测定蔬菜样品中的As、Cd、Cr、Hg、Pb含量评价重金属污染水平,并对污染来源进行解析。结果表明,萝卜中As、Cd、Cr、Hg、Pb的整体水平分别为0.040、0.022、0.359、0.003、0.220mg/kg;白菜中的整体水平分别为0.026、0.022、0.307、0.004、0.158mg/kg;大葱中的整体水平分别为0.014、0.017、0.204、0.002、0.104mg/kg,蔬菜样品中Cr、Pb存在超过《食品安全国家标准食品中污染物限量》(GB 2762—2017)限值的现象,超标率分别为17.65%～46.15%、3.85%～86.77%;蔬菜中5种重金属的富集系数为CdHgPbCrAs,蔬菜中Cr、Pb为中度或重度污染,其中白菜比萝卜和大葱更易受到污染;工业排放源是周边地区蔬菜重金属含量的主要来源,其对萝卜、白菜和大葱重金属的贡献率分别为65.4%、35.5%、97.3%。     

西江流域土壤镍含量特征及风险评估

西江流域作为广西省重要的农业生产区和有色金属矿产区,为保障土地安全利用,有必要全面了解其土壤镍含量特征和风险水平。分别采集自然土壤、旱地土壤、水田土壤和矿区土壤样品283、1 286、721、130件,以自然土壤为背景样品,进行空间分布特征分析,并进行风险评估。结果表明,西江流域土壤镍的背景值为25.60mg/kg,基线值为156.00mg/kg。不同土地利用类型的土壤镍含量表现为矿区土壤(42.50mg/kg)水田土壤(28.70mg/kg)旱地土壤(22.70mg/kg),在P0.05水平下,矿区土壤显著高于背景值,而旱地土壤、水田土壤与背景值差异不显著。中部和西南部地区镍含量较高,尤其是西南部的都安瑶族自治县和大化瑶族自治县,很多区域都超过了60mg/kg。以基线值作为标准或根据地积累指数进行评价,由于考虑了背景值,西江流域土壤镍污染水平不高。     

贵州水城典型铅锌矿区土壤和蔬菜中重金属累积特征及风险评价

以贵州水城茨冲永昌、仁活洞杉树林和凉山玉兰3个典型铅锌矿区为研究对象,采集了白菜、辣椒、玉米、马铃薯、黄豆、四季豆6种蔬菜样品及其对应的根际土壤样品。分析了蔬菜与土壤中Pb、Zn、Ni、Cd、Cr、As、Hg、Cu 8种重金属的含量及蔬菜对根际土壤重金属的累积特征,同时采用内梅罗综合污染指数法、目标危险系数法及综合质量影响指数法对土壤及蔬菜重金属污染进行评价。结果表明:根际土壤中Pb、Zn、Ni、Cd、Cr、As、Hg、Cu总平均值分别为1 198.2、2 378.8、53.0、7.0、122.6、56.9、0.37、107.5mg/kg,分别是贵州土壤环境背景值的34.0、23.9、1.4、10.0、1.3、2.8、3.4、3.4倍;不同蔬菜对土壤中不同重金属的富集能力有较大差异;内梅罗综合污染指数表明,研究区土壤中8种重金属均属于重污染;蔬菜中重金属对当地儿童、青壮年、中老年的总健康风险指数均大于1,存在健康风险;综合质量影响指数也表明,研究区的综合质量属于重度污染。     

石灰钝化法原位修复酸性镉污染菜地土壤

在湖南省湘潭县酸性(pH=5.47±0.64)镉污染((1.06±0.08)mg·kg~(-1))菜地,进行为期1年的田间修复实验。研究施用石灰类钝化剂(石灰石或生石灰)对菜地土壤镉(Cd)的有效性、当地常见蔬菜可食部位Cd含量的影响,分析蔬菜种植过程中农业投入品对表层土壤(20 cm)Cd积累的影响,确定Cd污染菜地蔬菜安全生产的措施。结果表明:与对照相比,施加4 500 kg·hm~(-2)CaCO_3或3 000 kg·hm~(-2)CaO分别使土壤pH升高了1.48和1.73,土壤有效态Cd含量分别降低了87.8%和78.1%;叶菜类、根茎类、茄果类和豆类蔬菜可食部位Cd含量分别降低了5.9%～70.5%、59.8%～65.8%、4.0%～50.0%和35.0%～76.4%,但施用4 500 kg·hm~(-2)CaCO_3或3 000 kg·hm~(-2)CaO不能使叶菜类、茄果类蔬菜中Cd含量降低到相应的国家食品安全标准限值(叶菜类蔬菜,0.2 mg·kg~(-1);茄果类蔬菜,0.05mg·kg~(-1))以下;蔬菜种植过程中施用的基肥、灌溉水、CaCO_3或CaO不会导致表层土壤Cd含量增加。在酸性Cd污染菜地施用CaCO_3或CaO、并种植低Cd积累蔬菜,可以实现蔬菜的安全生产。     

铜绿山矿区菜地土壤重金属污染特征

以铜绿山矿区菜地为研究对象,测定了土壤和蔬菜中Cu、Zn、Pb、Cd 4种重金属的含量,分析了土壤-蔬菜体系重金属的污染特征和蔬菜对重金属的富集能力。结果表明:矿区菜地土壤中重金属Cu、Zn、Pb、Cd的污染因子分别为10.63、1.12、1.10、0.06,表明Cu污染非常严重,Zn、Pb属轻度污染,Cd无污染;参考《食品中污染物限量》(GB 2762—2017)、《食品中铜限量卫生标准》(GB 15199—94)以及《食品中锌限量卫生标准》(GB 13106—91),蔬菜中Cu、Zn污染较严重且具有普遍性;蔬菜中Cd含量虽均未超出食品安全限值,但明显高于蔬菜根部土壤中的Cd含量;叶菜类、根茎类蔬菜中Pb均未超标,瓜果类蔬菜中Pb超标;蔬菜可食部位对重金属的富集能力为CdZnCuPb;蔬菜中重金属含量与土壤重金属含量总体表现出较弱的相关性,表明蔬菜中重金属的积累不完全决定于土壤重金属的含量,还与土壤中重金属的生物有效性、环境行为及其他环境因素有关。     

Search for chlorobornanes in river sediments and in influents and effluents

In 1997, we collected nine river sediment samples, including one duplicate, from above and below three pulp and paper mills on the Wisconsin River in Wisconsin, USA, and one mill on Beaver Dam Creek in Ontario, Canada. We also obtained twenty split sediment samples from the Wisconsin River that were collected by the US EPA in collaboration with Indiana University. Finally, we collected influent and effluent samples from eight pulp and paper related industries in the US and Canada. We analyzed all sediment and water samples for hexa- through decachlorobornanes. We did not detect any chlorobornanes in most of the sediments. When chlorobornanes were detected, the concentration in sediments below pulp mills were similar to or less than in those from above the same mills. Chlorobornanes could not be detected in any of the influent or effluent samples. Thus, pulp and paper mills and relate facilities are not a source of chlorobornanes.     

Occurrence and treatment of arsenic in groundwater and soil in northern Mexico and southwestern USA

This review focuses on the occurrence and treatment of arsenic (As) in the arid region of northern Mexico (states of Chihuahua and Coahuila) and bordering states of the southwestern US (New Mexico, Arizona, and Texas), an area known for having high As concentrations. Information assembled and assessed includes the content and probable source of As in water, soil, and sediments and treatment methods that have been applied in the area. High As concentrations were found mainly in groundwater, their source being mostly from natural origin related to volcanic processes with significant anthropogenic contributions near mining and smelting of ores containing arsenic. The affinity of As for solid phases in alkaline conditions common to arid areas precludes it from being present in surface waters, accumulating instead in sediments and shifting its threat to its potential remobilization in reservoir sediments and irrigation waterways. Factors such as oxidation and pH that affect the mobility of As in the subsurface environment are mentioned. Independent of socio-demographic variables, nutritional status, and levels of blood lead, cognitive development in children is being affected when exposed to As. Treatments known to effectively reduce As content to safe drinking water levels as well as those that are capable of reducing As content in soils are discussed. Besides conventional methods, emergent technologies, such as phytoremediation, offer a viable solution to As contamination in drinking water.     

Bacterial and archaeal diversity in oil fields and reservoirs and their potential role in hydrocarbon recovery and bioprospecting

Environmental Science and Pollution Research - Hydrocarbon is a primary source of energy in the current urbanized society. Considering the increasing demand, worldwide oil productions are declining...     

Accumulation in and effects of lead and cadmium on waterfowl and passerines in northern Idaho

Waterfowl and passerines in northern Idaho in 1987 had high levels of lead in their blood and tissues that originated primarily from mining and smelting activities. Four Canada geese (Branta canadensis) and one common goldeneye (Bucephala clangula) found dead contained 8 to 38 microg/g (wet mass) of lead in their livers. These levels exceed the lower lethal limit of 5 microg/g in experimental birds. Two of the Canada geese (one each from the contaminated and reference areas) died with ingested lead shotgun pellets (shot) in their gizzards, whereas the other three birds from the contaminated area contained no ingested shot and evidently died from ingesting environmental lead in sediment or biota. Lead burdens in most American robins (Turdus migratorius) and mallards (Anas platyrhynchos) were high, whereas those in tree swallows (Tachycineta bicolor) were slightly elevated. Lead accumulated to potentially hazardous levels in blood and tissues of some nestling robins (maxima of 0.87 microg/g in blood and 5.6 microg/g in liver) and mallards (maxima of 10.2 microg/g in blood and 2.8 microg/g in liver). In mallards, lead levels and associated physiological characteristics of blood were significantly different in juveniles (HY) versus adults (AHY). Activity of delta-aminolevulinic acid dehydratase (ALAD) was about 87 to 95% lower than values for control birds in experimental studies. Activity of ALAD was significantly inversely correlated with blood lead levels. Cadmium was detected in kidneys of most birds, but even the maximum concentration of 7.5 microg/g in an AHY mallard was below known harmful levels.     

Pinonaldehyde and some other organics in rain and snow in central Japan.

Solvent-extractable organic compounds in the rain and snow collected at local cities in the mountainous region in central Japan, were analyzed by GC/MS and GC. Pinonaldehyde (2,2-dimethyl-3-acetyl-cyclobutyl-ethanal), an atmospheric reaction product of alpha-pinene, was detected in the rain and snow for the first time, and n-alkanes (C17-C33), fatty acids (C8-C23), and benzoic acid were also detected as major organic components. Concentrations of pinonaldehyde, C17-C33 n-alkanes, C8-C11 fatty acids, C12-C23 fatty acids and benzoic acid ranged between <0.02-13, 0.10-35, 0.55-5.7, 4.2-19 and <0.02-6.0 microg/l, respectively. Their composition showed some difference in summer and winter. In summer, fatty acids and benzoic acid were more abundant, while pinonaldehyde and n-alkanes were much less. Higher photochemical reactivity and higher bioactivity in summer could explain these seasonal changes except for pinonaldehyde, which would suffer from further oxidation in the atmosphere after its photochemical production from alpha-pinene. Predominance of pinonaldehyde and C12-C23 fatty acids in the rain and snow showed a remarkable contrast to n-alkanes in aerosol phase, which were the most abundant components. It indicated that oxygenated products from biogenic compounds might be important as cloud condensation nuclei in forest areas.     

鸢尾和菖蒲不同器官对富营养化水体中氮磷的积累效应

将鸢尾和菖蒲种植在椰丝基质上并放入富营养化的水塘中,实验在自然条件下进行.分别测定鸢尾和菖蒲的根、茎、叶不同器官中氮、磷的含量和植物种植期间生物量的变化状况.结果表明,植物根、茎、叶对氮、磷的积累量有显著差异,叶是两种植物积累氮、磷的主要器官;叶中的氮、磷积累量在实验后期,即11月中下旬时达到峰值;菖蒲各器官氮、磷含量均高于鸢尾,但是单株鸢尾对氮、磷的积累量比菖蒲大.     

Fungi and bacteria in mould-damaged and non-damaged office environments in a subarctic climate

The fungi and bacterial levels of the indoor air environments of 77 office buildings were measured in winter and a comparison was made between the buildings with microbe sources in their structures and those without such sources. Penicillium, yeasts, Cladosporium and non-sporing isolates were the commonest fungi detected in the indoor air and in settled dust, in both the mould-damaged and control buildings. Aspergillus ochraceus, Aspergillus glaucus and Stachybotrys chartarium were found only in environmental samples from the mould-damaged buildings. Some other fungi, with growth requiring of water activity, a_w, above 0.85, occurred in both the reference and mould-damaged buildings, but such fungi were commoner in the latter type of buildings. The airborne concentrations of Penicillium, Aspergillus versicolor and yeasts were the best indicators of mould damage in the buildings studied. Penicillium species and A. versicolor were also the most abundant fungi in the material samples. This study showed that the fungi concentrations were very low (2–45 cfu m⁻³ 90% of the concentrations being <15 cfu m⁻³) in the indoor air of the normal office buildings. Although the concentration range of airborne fungi was wider for the mould-damaged buildings (2–2470 cfu m⁻³), only about 20% of the samples exceeded 100 cfu m⁻³. The concentrations of airborne bacteria ranged from 12 to 540 cfu m⁻³ in the control buildings and from 14 to 1550 cfu m⁻³ in the mould-damaged buildings. A statistical analysis of the results indicated that bacteria levels are generally <600 cfu m⁻³ in office buildings in winter and fungi levels are <50 cfu m⁻³. These normal levels are applicable to subarctic climates for urban, modern office buildings when measurements are made using a six-stage impactor. These levels should not be used in evaluations of health risks, but elevated levels may indicate the presence of abnormal microbe sources in indoor air and a need for additional environmental investigations.     

Occurrence and profiles of organic sun-blocking agents in surface waters and sediments in Japanese rivers and lakes

Sun-blocking agents including eight UV filters (UVF) and 10 UV light stabilizers (UVLS) were measured in water and sediment collected from 22 rivers, four sewage treatment plant effluents (STPE) and three lakes in Japan. Total sun blocking agents levels ranged from N.D. to 4928 ng/L and from 2.0 to 3422 μg/kg dry wt in surface water and in sediment, respectively. Benzyl salicylate, benzophenone-3, 2-ethyl hexyl-4-methoxycinnamte (EHMC) and octyl salicylate were dominant in surface water receiving wastewater effluents and STPE, although UV-328, benzophenone and EHMC were dominant in other surface water except background sites. Three UVF and nine UVLS were observed from all sediment and their compositions showed similar patterns with UV-328 and UV-234 as the most prevalent compounds. Homosalate, octocrylene, UV-326, UV-327, UV-328 and UV-234 were significantly correlated with Galaxolide^® in sediments. Concentrations of UV-327 and UV-328 also had strong correlation between those of UV-326 in sediment.     

Photodegradation of polychlorinated dibenzo-p-dioxins and dibenzofurans in aqueous solutions and in organic solvents

Aqueous solutions of selected polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were prepared using a generator column and exposed to UV (300 nm) light in the laboratory and to sunlight in an outdoor environment. In the laboratory, additional exposures were also carried out using 60% acetonitrile/water solutions. At 300 nm di- and tetra PCDDs had higher first-order photodegradation rate constants in 60% acetonitrile/water than in pure water. The solvent effect was reversed for PCDFs. These results may be a reflection of the higher polarity of PCDFs compared to PCDDs. In both the indoor and outdoor exposures photodegradation rates decreased with increasing concentrations of chlorination. However, OCDF exposed to 300 nm light in 60% acetonitrile/water and to sunlight in pure water photodegraded more rapidly than tetra CDF. Photolysis rates in sunlight were considerably slower (t(1/2) of 6.4-23 h) than photolysis rates at 300 nm in the laboratory (t(1/2) of 4.3-680 min), reflecting the lower intensity of sunlight in the 300 nm region of the UV/Vis spectrum. The extent of dechlorination of the PCDDs/PCDFs was less than 20% and reductive dechlorination does not appear to be a major process in the photodegradation of PCDDs/PCDFs in aqueous solutions.     

Flotation in water and wastewater treatment and reuse: recent trends in Brazil

This paper summarises environmental applications of conventional and unconventional flotation to remove pollutants from waters. Emphasis is given to the design features of innovative inline reactors, namely the Flocs Generator Reactor and Flocculation-Flotation, and their applications for the flocculation and flotation in solid-liquid separations involving water (and wastewater) treatment and reuse. Applications are shown in potable water clarification, treatment and water reuse from car washing units and in the treatment of acid mine drainage. Results show that these inline flocculation (or flotation) separators have a great potential for water/wastewater treatment and reuse, especially in applications requiring high rate solid-liquid separations.