Spatial distribution,pollution characterization and health risk assessment of selected metals in groundwater of Lahore,Pakistan

Groundwater pollution is a major global environmental issue especially in the large cities and trace metals are considered as most important aquatic pollutants. The present study is based on the measurement and characterization of various physicochemical parameters (pH, EC, TDS, DO, alkalinity, hardness, and chloride), major cations (Ca, Mg, Na and K) and selected trace metals (Sr, Li, Fe, Zn, Cu, Co, Mn, Ag, Cd, Cr, Ni, and Pb) in the groundwater of Lahore, Pakistan during summer and winter (2017–18) seasons. Groundwater is the main source of drinking water in urban areas of Lahore. Seasonal comparison of the data indicated that majority of the metals showed relatively higher concentrations during winter than summer. Most of the metals exhibited significant spatial variability during both seasons; relatively higher metal levels were found in the old settlements and thickly populated areas of the city. Average concentrations of Pb, Ni, Cd and Co in the groundwater were found to be higher than the national and international guideline values. Factor analysis and cluster analysis revealed major anthropogenic contributions of Ni, Co, Cd, Cu, Cr and Pb in the groundwater while rest of the metals showed mixed and/or natural contributions. Evaluation of human health risks for the metal contents in groundwater revealed that Pb, Co, Ni and Cd were associated with significantly higher non-carcinogenic risks (HQ_ing > 1); the calculated risk for children was considerably higher than the adults. Moreover, the carcinogenic risk associated with Ni, Cr, Cd and Pb exceeded the safe limits. The present study revealed significantly higher anthropic pollutants in the groundwater which imposed considerable risks to human; therefore, it is recommended to implement immediate remedial measures to ensure safe drinking water.     

Current situation and human health risk assessment of fluoride enrichment in groundwater in the Loess Plateau: A case study of Dali County,Shaanxi Province,China

This study aims to investigate the mechanisms and health risks of fluoride enrichment in groundwater in the Loess Plateau, China. By taking Dali County, Shaanxi Province, China as an example, this study obtains the following results through field investigation and the analyses of water, soil, and crop samples. (1) The groundwater can be divided into two major types, namely the Quaternary pore-fissure water and Karst water. The Karst area and sandy area have high-quality groundwater and serve as the target areas for optional water supply. The groundwater in the study area is slightly alkaline and highly saline. Meanwhile, high-fluoride groundwater is mainly distributed in the loess and river alluvial plains in the depression area of the Guanzhong Basin and the discharge areas of the groundwater, with the highest fluoride concentration exceeding seven times the national standard. (2) Fluoride in groundwater mainly originates from a natural source and human activities. The natural source refers to the fluoride-bearing minerals in rocks and soil, and the fluoride from this source is mainly controlled by natural factors such as climate, geologic setting, pH, specific hydrochemical environment, ion exchange, and mineral saturation. Human activities in modern life can be further divided into industrial and agricultural sources primarily. (3) The health risks of fluoride contamination are very high in the Loess Plateau, especially for children compared to adults. Meanwhile, the risks of fluoride exposure through food intake are higher than those through drinking water intake. The authors suggest selecting target areas to improve water supply and ensure the safety of drinking water in the study area. Besides, it is necessary to plant crops with low fluoride content or cash crops and to conduct groundwater treatment to reduce the fluoride concentration in drinking water. These results will provide a theoretical basis for safe water supply in the faulted basin areas in the Loess Plateau.© 2021 China Geology Editorial Office.     

Characterization of arsenic-contaminated groundwater and human health risk assessment in Vietnam

The characteristics of arsenic-contaminated groundwater were investigated and the potential risks from groundwater were evaluated in Vietnam. Arsenic contamination in groundwater was found in Ha Nam Province in the northern part of Vietnam. Since groundwater has been used as one of the main drinking water sources in this region, groundwater （n=10） and hair （n=15） samples were collected in the Vinh Tru district, Ha Nam Province, during February of 2006. At the site, the concentrations of anions and silica were analyzed and As（Ⅲ） and As（Ⅴ） species in groundwater were separated with disposable arsenic speciation cartridge. The concentrations of arsenic in groundwater ranged from 13 to 582 μg/L （mean=366 μg/L）. According to the results of arsenic speciation, approximately 90% of arsenic in groundwater existed as As（Ⅲ） species. Average concentrations of iron and manganese were 18 and 0.7 mg/L, respectively. All samples exceeded the Vietnamese drinking water standard of 10μg/L for arsenic and 0.5 mg/L for iron. Also 70% of the groundwater samples were above the Vietnamese drinking water standard of 0.5 mg/L for manganese. However, a real intake of arsenic to human is less than analyzed arsenic concentration because sand filtration units are used to remove iron and arsenic in groundwater in this region. After treatment, arsenic concentrations decreased from 〈1 to 82 μg/L （mean=33 μg/L）. The concentrations of arsenic in hair samples and treated groundwater were compared. Especially, arsenic concentrations in female hair samples and treated groundwater had significantly positive correlation with the Spearman correlation of 0.88 and the P-value of 0.001. Based on the arsenic concentrations in treated groundwater, the assessment of human health risks was conducted.     

污染场地健康风险评价的理论和方法

综合国外研究进展介绍了污染场地健康风险评价的基础理论和评价方法,基础理论主要从人体摄取污染物质的方式和机制以及污染物摄取剂量和人体健康效应的关系两方面开展讨论。评价方法从数据收集、暴露评估、毒性评估和风险表征4方面进行探讨。在此基础上,对评价方法进行了探讨,提出了“叠加风险”和“多暴露途径同种污染物累计健康风险”的概念和计算方法,分析了中国开展污染场地健康风险评价的相关问题,指出构建中国污染场地健康风险评价体系应从制定法律入手,以典型污染场地风险评价为试点,逐渐建立和完善风险评价指南和技术细则,最终完成包括法律法规、评价指南和技术细则等在内的污染场地健康风险评价体系的建立。     

污染场地健康风险评价的实例研究

以常州市A厂有机污染调查为依据,采用篇中讨论的污染场地健康风险评价方法综合评价由土壤、空气、地下水污染带来的人群健康风险。综合分析表明,场地目标污染物为4种苯系物,可能对人体产生肝肾病变、鼻上皮组织恶化和运动协调能力降低等非致癌效应;污染物暴露途径主要有3条,分别暴露于厂区人群和饮用厂区下游民井井水的居民。评价结果显示,厂区人群同时遭受皮肤接触污染土壤和呼吸污染空气带来的非致癌危害。4种污染物的多途径同种污染物累计非致癌危害指数分别为甲苯,2·82×10-2;乙苯,4·94×10-2;间对二甲苯,1·21×10-7;异丙苯,1·05×10-7。两途径多污染物非致癌总危害指数分别为4·26×10-5和7·76×10-2,非致癌综合危害指数为7·76×10-2;厂区下游居民饮用遭受污染的地下水,其多污染物非致癌总危害指数为1·55×10-5。各危害指数均小于1,非致癌健康风险较小。     

鄱阳湖平原地下水重金属含量特征与健康风险评估

鄱阳湖平原作为长江中下游平原的重要组成部分,随着城镇化进程的快速推进,由于工矿业污染物、农村生活污水和农业生产废水向地下水的过量排放,农村地下水污染程度和范围不断扩大,为了解鄱阳湖平原地下水重金属污染状况,本研究在大量的水文地质调查和水化学样品测试基础上,分析该区地下水中重金属Cu、As、Cr、Hg、Pb、Cd含量特征,利用美国环境保护署(USEPA)的健康风险评价模型对鄱阳湖平原地下水重金属进行健康风险评价。研究区171个地下水样品中Cd、Cu、Hg、As、Pb、Cr等6种重金属元素含量变化幅度大,其中Hg、Cd和As平均值超过《地下水环境质量标准》(GB/T14848—2017)Ⅲ类标准,结果表明鄱阳湖平原地下水水质受人为影响大,局部地下水存在严重的污染。致癌物健康风险评价结果显示,Cr、As和Cd的平均个人年健康风险值均大于可接受风险值,Cr的健康风险值最大,是主要的致癌因子,As次之,Cd最低;非致癌物质健康风险结果显示,Hg、Pb和Cu的健康风险水平表现为Hg>Pb>Cu,属于可忽略风险。区域饮水途径上的健康风险主要来自致癌物质,总体上男性健康风险大于女性的健康风险。鄱阳湖平原地下水水质污染状况研究及治理监管工作提供理论依据,为其他区域地下水重金属的监测和质量控制提供参考和借鉴。     

黄骅地区水-土系统地球化学环境健康风险评估

对黄骅地区土壤、粮食籽实(小麦、玉米)及饮用水中出现严重污染的元素进行风险分析和风险评估,划分风险管理分区并提出相应管理措施.笔者结合土壤、粮食籽实(小麦、玉米)及饮用水样品中超标元素,综合分析后选取Cd、Cu、Hg、Pb、Zn、As、Ni、F、I、Se、Cr共11种重点元素作为风险评估的指标,建立人体单位体重日均食用暴露剂量模型(CDI),并采用风险商值法进行风险等级划分,并将多种元素的风险区域合并叠加形成风险管理分区.结果显示,黄骅地区11个评估指标中F的风险系数HQ值全部大于1,I的HQ值大于1的样品占52%,Pb只有一个样品的HQ值大于1,其他元素的HQ值全区均小于1.水土综合高风险区主要出现在黄骅西南部常郭-旧城-羊二庄一带,次高风险区为北部齐家务、南排河,风险主要由地下水引起.     

The distribution and hydrogeological controls of fluoride in the groundwater of central Ethiopian rift and adjacent highlands

Occurrence of fluoride (F) in groundwater has drawn worldwide attention, since it has considerable impact on human health. In Ethiopia high concentrations of F in groundwaters used for community water supply have resulted in extensive dental and skeletal fluorosis. As a part of a broader study, the distribution of F in groundwater has been investigated, and compared with bedrock geology and pertinent hydrochemical variables. The result indicates extreme spatial variations. High F concentration is often associated with active and sub-active regional thermal fields and acidic volcanics within high temperature rift floor. Variations in F can also be related to changes in calcium concentration resulting from dissolution of calcium minerals and mixing with waters of different chemical composition originated from variable hydrogeological environment across the rift valley. The concentration of F dramatically declines from the rift towards the highlands with the exception of scattered points associated with thermal springs confined in local volcanic centers. There are also interactions of F-rich alkaline lakes and the surrounding groundwater. Meteoric waters recharging volcanic aquifers become enriched with respect to F along the groundwater flow path from highland recharge areas to rift discharge areas. Locally wells drilled along large rift faults acting as conduits of fresh highland waters show relatively lower F. These areas are likely to be possible sources of better quality waters within the rift. The result of this study has important implications on site selection for water well drilling.     

淮南潘一矿采煤塌陷积水区水环境健康风险评估

以淮南潘一矿塌陷积水区为例,分析测试了塌陷积水区12个采样点水样中的7种重金属元素（Cr、Cd、Zn、Cu、Pb、Ni和Fe）的含量,采用美国环保局（USEPA）推荐的水环境健康风险评价模型,对重金属由食入途径进入人体所引起的健康风险进行评估和分析。研究发现,研究区水体中重金属致癌风险值为（5.06~8.06）×10^-6/a,根据我国环境保护部推荐的健康风险标准,存在健康风险。其中,Cr的致癌风险占总致癌风险的98.52%。非致癌健康风险值在10^-10/a的数量级,健康风险不明显,而非致癌健康风险的贡献大小顺序为,Cu > Pb > Fe > Cr > Cd > Ni > Zn。其中,Cu的贡献率最大,占非致癌总风险值的48.62%。同时还发现,研究区的重金属致癌风险占总健康风险的99.99%,这表明该区域总的水质健康风险几乎全部由致癌风险构成,而致癌风险中又几乎由Cr组成。     

豫西钼矿集区地表水重金属时空分布特征及健康风险评价

豫西钼矿集区内长期的矿产资源开发向周围环境释放大量的重金属,区内地表水环境质量现状尚不明晰。于2019年丰水期（8月）和枯水期（12月）对矿集区内5条河流进行地表水采集,调查地表水重金属（Mo、Cd、Hg、As、Cr、Cu、Pb、Zn）的时空分布特征,并用健康风险模型评价地表水重金属人体健康风险。结果表明,丰水期地表水主要污染元素为Mo、Zn和Cd,而枯水期地表水主要污染元素为Mo、Hg和Cd,大多数点位地表水符合II类标准。地表水中的Mo主要来源于钼矿;Pb和Zn主要来源于钼矿和铅锌矿;Cd主要源于金矿和铅锌矿;Hg主要源于金矿。健康风险评价结果表明,地表水重金属通过饮用水途径所致的总个人年健康风险均低于美国环保署（US EPA）推荐的最大可接受风险水平。除丰水期成人总个人年健康风险低于国际辐射防护委员会（ICRP）推荐的最大可接受风险水平外,丰水期儿童、枯水期成人和儿童高于ICRP推荐的最大可接受风险水平。研究的结果可为钼矿集区地表水污染防治和风险管控提供科学依据。     

Isotopic geochemistry of the groundwater system in arid and semiarid areas and its significance: a case study in Shiyang River basin, Gansu province, northwest China

 Shiyang River basin, located in the eastern part of Hexi Corridor in the middle Gansu province, NW China, is a typical arid to semiarid area. Within its drainage distance of merely 300 km, the groundwater system shows a gradual hydrochemical zonation from the upper reach to the lower reach, which is composed of hydrocarbonate, sulfate to chloride zones respectively. Variation in the saturation index (SI) of calcite and dolomite shows that, under arid to semiarid conditions, the drastic evaporation causes the groundwater quality to deteriorate in the lower reach. Isotopic compositions of H, O and He in the groundwater show that the groundwater recharge sources are mainly from meteoric water. δ³He–³He/²⁰Ne coordinates could clearly distinguish the water sources and mixing among them. In the Caiqi region, there is apparent mixing of the crevice water containing excess ⁴He with the overlying groundwater, which also implies a much lower circulation rate of the groundwater. Fairly high ³He/⁴He ratios of the groundwaters collected from the adjacent area of hidden faults along Qilian Mountains show the eminent input of mantle-derived helium, indicating that these faults not only cut the crust deeply, but are currently active. Received: 11 February 2000 · Accepted: 23 May 2000     

Hydrochemical framework of the aquifer in and around East Kolkata Wetlands,West Bengal,India

The area lies between Hugli river in the northwest and Bidyadhari river in the east and includes the East Kolkata Wetlands. The East Kolkata Wetlands is included in the List of Wetlands of International Importance (“Ramsar List”), as per the Convention on Wetlands signed in Ramsar, Iran, in 1971. This wetland has been declared as a Ramsar site on the 19th August 2002 (Ramsar site no. 1208) and therefore has acquired an international status. The area is a part of the lower deltaic plain of the Bhagirathi–Ganga river system and is generally flat in nature. The sub-surface geology of the area is completely blanketed by the Quaternary fluviatile sediments comprising a succession of clay, silty clay, sand and sand mixed with occasional gravel. The Quaternary aquifer is sandwiched between two clay sequences. The confined aquifer is made up of moderately well sorted sand and reflects fluviatile environment of deposition. The regional groundwater flow direction is from east to west. Detailed geochemical investigations of 40 groundwater samples along with statistical analysis (for example, correlation and principal component analysis) on these chemical data reveal: (i) four types of groundwater quality, for example, good, poor, very poor and water unsuitable for drinking purpose, (ii) four hydrochemical facies which may be assigned to three broad types such as “fresh”, “blended”, and “brackish” waters, (iii) the evolution of the “blended” water is possibly due to hydraulic mixing of “fresh” and “brackish” waters within the aquifer matrix and/or in well mixing, and (iv) absence of Na–Cl facies indicates continuous flushing of the aquifer.     

关中盆地浅层地下水氮污染的健康风险评价

为了研究关中盆地浅层地下水氮污染对人体产生的潜在健康危害风险,在研究区采集和测试了232个水样,采用单因子污染指数法和健康风险评价模型对浅层地下水氮污染进行了评价。结果表明,在浅层地下水中硝态氮污染程度相对较重,呈面状分布;而铵态氮和亚硝态氮污染程度较轻,以点状存在。浅层地下水中硝态氮对人体健康的慢性毒害指数较高,高风险区占研究区面积的78.2%,主要分布在农业活动强烈的灌区和人口居住密集、工业相对发达的城镇区;硝态氮含量大于12.6mg/L的三类地下水对人体健康也是高风险的,即传统意义上可以饮用的三类水对人体健康并不都是安全的。上述成果对地下水资源管理和保护具有重要的参考价值。     

Temporal variations of fluoride concentration in Isparta public water system and health impact assessment (SW-Turkey)

Water–rock interaction is one of the prime factors affecting the fluoride contents of surface and groundwater. If fluoride concentration of drinking water has been neglected, excess fluoride can cause serious dental and medical problems on human health, which is well known at Golcuk-Isparta region. In the research area, Egirdir lake, Golcuk lake and surrounding springs have been utilized as drinking water sources. Golcuk lake water and surrounding groundwaters have high fluoride content (1.4–4.6 mg/l), which is above the WHO standards. Fluoride is predominantly supplied by dissolution of fluoride within the fluormicas of volcanics during the circulation of water. Fluoride concentrations of waters have shown variations for dry and rainy seasons depending on the degree of interaction between groundwater and volcanic rocks. It tends to decrease in rainy seasons and increase in dry seasons for all years. In this study, temporal variations and spatial distribution of fluoride concentration in public water system of Isparta were investigated to get benefit using GIS techniques from1990 to 2003 years. Extremely fluoride concentrations were measured in the public water system in 1990 at almost every district of the city. In 2003, fluoride content of the public water system decreased in some district of city due to drinking water has started obtaining from Egirdir lake in 1995. The fluoride contents of Isparta drinking water ought to be modified with suitable mixture of lake waters and groundwater point of view to health impact.     

陕西潼关县金矿矿区周边农田土壤重金属生态健康风险评价

为了解潼关金矿矿区早期粗放式的矿业活动对矿区周边农田土壤的重金属污染状况的影响以及对暴露人群的不良健康效应的评价,采用地质调查工程选取了矿区附近6块农田土壤为研究对象,通过X射线荧光光谱分析法测定了68个土壤样本中Cd、Hg、As、Pb、Cr、Cu、Ni、Zn等8种土壤重金属含量,采用地累积指数法、潜在生态危害指数法和...     

北京城乡接合部地表颗粒物中重金属污染负荷及健康风险评价

随着我国城市建设的不断推进,城市径流污染越来越受到关注。地表颗粒物(RDS)是重金属的重要载体,雨水径流对地表颗粒物的冲刷引起的径流重金属污染问题凸显。本研究选取北京市城乡接合部作为研究区域,研究区域内地表颗粒物中重金属(As、Cd、Cr、Cu、Mn、Pb、Zn)污染负荷并进行健康风险评估。结果表明,地表颗粒物含有的重金属中,除Mn外,As、Cd、Cr、Cu、Pb、Zn的平均浓度均超过背景值。其中,Cd的平均浓度是其背景值的3倍,Cr的平均浓度是其背景值的4倍之多。在径流冲刷条件下,Cr的污染负荷在各研究区域均最高,为其他重金属的3~4倍。暴露模型计算表明,重金属非致癌日平均暴露量为手口摄入量＞皮肤吸收量＞吸入空气量,经手口接触是人体地表灰尘暴露风险的主要途径。对于非致癌风险,在芦求路主路以及黄鹅路十字路口区域存在对于儿童的非致癌风险,整体区域内成人所受非致癌风险较低。各研究区域内重金属呼吸暴露途径的总致癌风险均低于环境阈值,致癌风险较低。     

江西赣州地区土壤-水稻系统重金属含量特征及健康风险评价

为研究江西省赣州市主要耕作区土壤-水稻系统中重金属的含量及人体健康风险,系统采集了赣州市主要耕作区水稻及根系土样品954组,分析了水稻籽实和根系土中Cd、Cr、Hg和Pb的含量及根系土pH值,利用美国环保署（USEPA）推荐的健康风险评估模型进行健康风险评价。研究表明：随着土壤pH值升高,水稻籽实中各重金属元素超标率逐渐降低,其中Cd是土壤和水稻中最主要的污染元素;在土壤-水稻系统中,Cd的迁移能力和土壤pH值是决定水稻籽实重金属是否超标的主要因素。健康风险评价结果显示,研究区重金属总非致癌风险指数HI < 1,说明几乎不存在由食用水稻得慢性疾病的风险。致癌健康风险值为7.10×10-3,Cd是最主要的致癌风险因子,Cr和Pb致癌风险属于可接受范围。基于行政单元的人体健康风险区划表明,上犹县、兴国县和南康区存在一定的风险,虽然重金属没有出现显著超标,但是有关部门应对水稻及根系土中Cd元素含量予以重视,将Cd元素作为赣州市土壤重金属污染防控工作中优先控制的重金属。     

基于生物可利用性与宽浓度范围的Hakanson潜在生态风险指数法的创建——以小秦岭金矿区农田土壤为例

Hakanson潜在生态风险指数法是土壤重金属潜在生态风险评价的一种常用方法,研究与实践证明其有效性的同时,也发现了其不足之处:忽略了土壤重金属不同形态之间潜在生态风险的差异,且只重视重金属含量高于参考值时的生态风险,而对低于参考值时的情况没有给予考虑,以致特定情况下的评价结果不能很好地反映实际生态风险,因而有必要创建适用性更广的Hakanson潜在生态风险指数法。为此,基于全过程控制优化的思想,引入了生物可利用性毒性系数,并将修正浓度与参考值差值引入计算公式,创建了基于生物可利用性与宽浓度范围的Hakanson潜在生态风险指数法,实现了对重金属不同形态风险贡献的差异及重金属浓度低于参考值情况下潜在生态风险的准确把握。以小秦岭金矿区为典型区域,辅以对采集土样重金属总量及5种形态含量的分析,开展案例研究。结果表明,基于生物可利用性与宽浓度范围的Hakanson潜在生态风险指数法能客观地揭示土壤重金属的潜在生态风险,具有更大的适应性,是一种有效的潜在生态风险评价方法。     

基于脆弱性指数法的韩城矿区11号煤层底板突水危险性评价

在全面分析韩城矿区地质与水文地质条件的基础上,应用相关因素分析方法,提出研究区煤层底板奥灰含水层突水的指标体系,并以多个典型煤矿为例,重点分析了受奥灰含水层威胁最严重的11号煤层底板突水的影响因素;构建了有效隔水层厚度、褶皱规模、含水层富水性、断层规模4个评价指标;采用脆弱性指数评价方法对11号煤层底板突水的危险性进行了分区。     

Drinking water quality in villages of southwestern Haryana,India: assessing human health risks associated with hydrochemistry

The chemical quality of groundwater of western Haryana, India was assessed for its suitability for drinking purposes. A total of 275 water samples were collected from deep aquifer based hand-pumps situated in 37 different villages/towns of Bhiwani region. The water samples were analyzed for different physico-chemical properties, e.g., pH, total dissolved solids (TDS), total harness (TH), total alkalinity (TA), calcium, magnesium, carbonate, bicarbonate, sulphate, chloride and fluoride concentrations. In this study, the average TDS content was greater ranging 1,692 (Bhiwani block) to 2,560 mg l⁻¹ (Siwani block), and other important parameters of water, e.g., TA (442–1,232 mg l⁻¹), TH (437–864 mg l⁻¹) and bicarbonate (554–672 mg l⁻¹), were also higher than maximum permissible limit by WHO or BIS. The fluoride appeared as a major problem of safe drinking water in this region. We recorded greater fluoride concentration, i.e., 86.0 mg l⁻¹ from Motipura village that is highest fluoride level ever recorded for Haryana state. The average fluoride concentration ranged between 7.1 and 0.8 mg l⁻¹ in different blocks of western Haryana. On the basis of fluoride concentration, Siwani block showed the maximum number of water samples (84% of total collected samples) unsuitable for drinking purposes (containing fluoride >1.5 mg l⁻¹) followed by Charki Dadri block (58%), Bhiwani block (52%), Bawani Khera block (33%) and Loharu block (14%). This study clearly suggest that some health deteriorating chemicals in drinking water were at dangerous level and; therefore, water quality could be a major health threat for local residents of western Haryana. The high fluoride level in drinking water has posed some serious dental health risks in local residents.