Assessment of risk to human health due to intake of chromium in the groundwater of the Aosta Valley region,Italy

The aim of this study is to assess the risk to human health presented by total chromium (Cr_T) and hexavalent chromium (Cr(VI)) due to the intake of the groundwater (shallow aquifer) in the Aosta Valley region. One hundred and fifty-three groundwater samples were collected from seventeen locations in the Aosta Valley region during the years 2007–2015 to determine the Cr_T and Cr(VI) concentrations. The cancer risk (CR) and non-cancer risk, reflected by the hazard quotient (HQ) were estimated using the United States Environmental Protection Agency methods. The concentrations of Cr_T exceeded the limit for drinking water established by Italian legislative decree at the sampling location Ao23 in all the years studied. Moreover, Cr(VI) concentrations exceeded the limit for drinking water at many sampling locations in the study area. The estimated HQ values for non-cancer risk suggested that all the sampling locations were well within the safe zone during all the years except for location Ao23 in many years considered. The CR levels were very low to high risk in the groundwater of the study area. The results of this analysis suggest that a suitable treatment of the groundwater is required before its utilization for drinking purposes. This study could be of great value for the prevention of risk to human health and for groundwater resource management.     

Health risk assessment of arsenic in soils from three thermal power plants in Southwest China

Abstract

High levels of arsenic (As) contamination in soils from thermal power plants pose a great threat to human health. This study aimed to evaluate the As contamination levels and assess the possible health risk of As in soils from three typical thermal power plants in Southwest China. The concentration of As was detected by using novel collision/reaction cell technology (CCT) with inductively coupled plasma mass spectrometry (ICP-MS, collectively ICP-CCT-MS) after aseptic digestion of soil samples. The carcinogenic risk and hazard quotient were estimated for health risk to workers in the study area by using “Chinese Technical Guidelines for Risk Assessment of Contaminated Sites (HJ 25.3-2014)”. Results showed that the concentration of As was between 3.65 and 33.80?mg/kg, and the comprehensive carcinogenic risk level of As was 3–28 times over the maximum acceptable level (10^?6), indicating that workers in the study area are facing serious threat of As. Oral ingestion (76.65%) was the main exposure pathway to carcinogenic risk, followed by skin contact (13.15%) and inhalation of soil particles (10.20%). After calculating the safety threshold values under three different exposure pathways (oral ingestion, skin contact and inhalation of soil particles), the minimum safety threshold value (1.59?mg/kg) was selected as the reference safety threshold value of As in the study area. These results provide basic information of health risk assessment of As and environmental management in thermal power plant areas.     

贵州兴仁煤矿区农田土壤重金属化学形态及风险评估

为了解煤矿区周边农田土壤重金属污染状况,采集了贵州省兴仁县某典型煤矿区农田土壤样品64份,测定了土样中重金属(As、Cr、Pb、Zn、Cd、Hg、Cu、Ni)总量及各形态含量,采用单因子指数法、潜在生态风险指数法(Hkanson法)和风险评估编码法(RAC)对研究区主要土壤利用类型(水稻土、薏米地、植烟土和菜园土)中重金属进行潜在生态风险评估和环境风险评价.结果表明： 不同利用类型土壤中重金属含量除Zn外,其他元素均明显超过贵州省背景值.单因子指数法评价结果表明,As、Pb、Hg和Cu污染较为严重,均属重度污染.形态分析表明,土壤中重金属形态构成差异明显,酸可提取态As、酸可提取态Cd所占比例较高;Cr、Zn、Cu、Ni主要以残渣态为主;Pb主要以可还原态和残渣态为主;而Hg的酸可提取态、可还原态、可氧化态均占有相当比例,三者之和大于55%.重金属可利用度大小顺序为:As(63.6%)>Hg(57.3%)>Cd(56.4%)>Pb(52.5%)>Cu(45.7%)>Zn(32.8%)>Ni(26.2%)>Cr(13.2%).潜在生态风险指数表明,各类型土壤潜在生态风险(RI)〖JP2〗为:菜园土(505.19)>薏米地(486.06)>植烟土(475.33)>水稻土(446.86),均处于较高风险.风险评估编码法结果显示,As在水稻土、薏米地及植烟土中均处于高风险,在菜园土中处于中等风险;Cd、Hg均处于中等风险,Cr、Pb、Zn、Cu和Ni均处于低风险.因此,对该区域农田土壤进行管控时应重点考虑As、Cd和Hg污染.     

Monitoring of arsenic in drinking water of high schools and assessment of carcinogenic health risk in Multan,Pakistan

Abstract

This study was performed to measure arsenic (As) contents in groundwater/drinking water of high schools and its effects on human health. Chronic daily intake, hazardous quotient (HQ), carcinogenic risk (CR), hazardous index (HI), and carcinogenic indices (CI) for oral and dermal exposure to arsenic were calculated. Samples were taken from high schools in four tehsils of Multan. As contents ranged from 3.25 to 184?µg/l and 99% samples exceeded World Health Organization safe limit (10?µg/l). HQ for Multan city (1.70) and for Multan Saddar (1.38) exceeded USEPA permissible toxic risk value (1.0). CR in four tehsils for oral (0.0001–0.0003) and dermal exposure (0.0000049–0.000011) exceeded USEPA limit (10^?6). HI for tehsil Multan city (1.75) and Multan Saddar (1.42) exceeded the limit (1.0). CI for four tehsils ranged from 0.00022 to 0.0008 exceeding USEPA limit (10^?6) indicating high chronic and carcinogenic health risk to exposed population. Results indicated that groundwater of district Multan is not fit for human consumption due to excessive arsenic contamination. It invites attention of water supplying agency and educational authorities to take steps for provision of arsenic free safe drinking water to students and local area peoples.     

Health risk assessment due to exposure of arsenic contamination in drinking water of district Shiekhupura,Punjab, Pakistan

Abstract

The present study was conducted to assess the magnitude and health impacts of As in drinking water. Drinking water samples (n?=?60) were collected from twenty different sites of Shiekhupura District (Pakistan). Health risk assessment through average daily dose (ADD), hazard indices (HI), hazard quotient (HQ), carcinogenic risk (CR), and cancer indices (CI) for dermal and oral exposure were determined. Results revealed that As concentration ranged from 2 to 900?µg?L^?1 in water samples, which was significantly greater than the safe limit of As (10?µg?L^?1) in water. Health risk assessment of As showed that ADD (1.07E?02–9.85E?04), HQ (1.06E+01–9.85E+00), and CR (1.60E?02–9.85E?04) for oral exposure and ADD (1.03E?05–9.69E?06), HQ (1.19E?02–7.96E?03), and CR (1.11E?05–8.98E?05) for dermal exposure which were exceeded the toxic risk index value. Comparison of the two exposure pathways indicated that the oral exposure is much higher risk than the dermal contact. Both values of HI and CI were greater than WHO limit. It is concluded that residents of study area are at higher risk of As induced diseases and carcinogenicity.     

Characterization and human health risk assessment of trace metal in PM10 in Bac Giang,short-term study in a developing province in Vietnam

Abstract

This study investigated the airborne concentration of PM₁₀ and 20 trace elements (Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, Na, Pb, Ti, V, Zn) in residential, industry, traffic road, coal mining, thermal power plant area of Bac Giang province. The average PM₁₀ concentration was highest at coal site, followed by traffic 1 sites, industrial sites and traffic 2 sites, the residential sites, and lowest at the power plant site located in mountain area. While Al, Ca, Fe, K, Mg, Na were the most abundant elements in all sampling sites, accounting for 73–96% of total obtained elements, the concentration of As, Cd, Cr, Cu, Mn, Ni, Pb, V, and Zn occupied from 2.9 to 23.2%. Noticeably, the concentrations of Cd were from 7 to 65 times higher than the concentration limit for Cd (0.1?ng/m³) according the World Health Organization (WHO). Although, the Hazard Index (HI values) of all metals were found to be within the safe level for both children and adults, the Carcinogenic Risk (CR) of Cr and As in all sites were closed to the acceptable levels for children, implying a potential carcinogenic risks of these metals.     

Arsenic and Heavy Metal Concentrations in Drinking Water in Pakistan and Risk Assessment: A Case Study

The present study was performed to assess drinking water quality and potential health risk in the Nowshera District, Khyber Pakhtunkhwa, Pakistan. For this purpose drinking water samples were collected from local available sources and analyzed for physico-chemical characteristics, arsenic (As) and heavy metals. Results revealed high levels of toxic heavy metals such as chromium (Cr), nickel (Ni), lead (Pb), cadmium (Cd), and As contaminations in the drinking water. Results were evaluated for chronic risk including average daily intake (ADI) and hazard quotient (HQ). Among heavy metals the HQ values were highest for Cd (5.80) and As (2.00). Therefore, populations in the study area may be at a low level of chronic toxicity and carcinogenic risk. Statistical analyses showed that contribution of different drinking water sources to the mean contaminant levels in the study area was insignificant (p =.53). Correlation analysis further revealed that anthropogenic activities were the main sources of contamination, rather than geogenic. This study strongly recommends the treatment of urban and industrial wastewater in the vicinity of the study area and provision of safe drinking water.     

Heavy metals in urban and peri-urban soils of a heavily-populated and industrialized city: Assessment of ecological risks and human health repercussions

Abstract

Increasing levels of heavy metals in soil have become a serious concern for human health because they can be easily transferred into the human body through contaminated food web. It is imperative to evaluate pollution levels, origin and ecological risks of heavy metals. The geoaccumaualtion (Igeo), contamination factor (CF), pollution load index (PLI) and human health risk were estimated to determine the soil pollution in Faisalabad, a heavily-populated and industrialized city of Pakistan. The maximum CF (1.58) and PLI (1.22) values were estimated for Cd and Pb, respectively, and maximum Igeo (?0.19) value was observed for Cd. Correlation analysis and principal component analysis suggested that common industrial sources for Cd and Pb were identified in the study sites. It clearly indicates that the significant levels of heavy metals pollution arise from local industries, busy commercial centers and heavy traffic load in the last few decades in heavily-populated and industrialized city. Further, soil heavy metals concentration were used to evaluate the human health risk such as chronic or non-carcinogenic including hazard indexes HIexP (ingestion, inhalation and dermal and carcinogenic) and cancer risk (CR). The HIexP values of Pb (10.30) and Cd (4.56) were found above the permissible limit (HI = 1) for children. The CR due to carcinogenic metals (Co, Cr and Cd) are within the safe limit (1E-06 to 1E-04). However, CR was comparatively higher in adults as compared to children. The results from the current investigation can help to develop a sustainable strategy in the study region to minimize the entry of heavy metals in food chain through source identification and pollution abatement techniques.     

Isolation of hexavalent chromium-reducing anaerobes from hexavalent-chromium-contaminated and noncontaminated environments

Hexavalent chromium [Cr(VI)], is a toxic, water-soluble contaminant present in many soils and industrial effluents. Bacteria from various soils were examined for Cr(VI) resistance and reducing potential. Microbes selected from both Cr(VI)-contaminated and-noncontaminated soils and sediments were capable of catalyzing the reduction of Cr(VI) to Cr(III) a less toxic, less water-soluble form of Cr, demonstrating the utility of using a selection strategy for indigenous Cr(VI)-reducing bacteria in a bioprocess. As a result, indigenous Cr(VI)- reducing microbes from contaminated sites should provide the means for developing a bioprocess to reduce Cr(VI) to Cr(III) in nonsterile effluents such as those from soil washes. This approach also avoids the contamination problems associated with pure cultures of allochthonous microorganisms. In addition the apparent ubiquity of Cr(VI)-reducing bacteria in soil and sediments indicates potential for in situ bioremediation of Cr(VI)-contaminated soils and ground water.     

Assessment of heavy metal pollution and human health risk in urban soils of a coal mining city in East China

The aims of this study were to determine the concentrations, distribution, potential ecological risk (PER), and human health risk (Risk) of heavy metals in urban soils from a coal mining city in China. A total of 36 topsoil samples from Huainan city, Anhui, East China, were collected and analyzed for As, Hg, Pb, Cd, Cr, and Cu. The PER was calculated to assess the pollution level. The hazard index (HI) and carcinogenic risk were used to assess the human health risk of heavy metals in the study area. The average concentration of As, Hg, Pb, Cd, Cr, and Cu were 12.54, 0.21, 24.21, 0.19, 49.39, and 21.74 mg kg^?1, respectively. The correlations between heavy metals indicated that Cu, Cr, Cd, and Pb mainly originated from automobile exhaust emissions, coal gangue, fly ash, and industrial wastewater, and that As and Hg mainly came from coal combustion exhaust. The PER index values of heavy metals decreased in the following order: Hg > Cd > As> Cu > Pb > Cr. The HI and Risk values indicated that the noncarcinogenic and carcinogenic risks of selected metals in the urban soil were both below the threshold values.     

Metal pollution in water environment and the associated human health risk from drinking water: A case study of Sukinda chromite mine,India

Sukinda is one of the most polluted regions of the globe due to chromium pollution. The study sheds light into the heavy metal pollution around the mining area and its effect on the health of the resident populace. The Cr(VI) was in the range of 0.027–2.48 mg/L in surface water and BDL–1.35 mg/L in the groundwater. Multivariate analysis revealed that mining activity was the main source of TCr, Cr(VI), and Zn in the surface water that warrants attention. Heavy metal evaluation index showed high levels of Fe, Mn, and Cr in groundwater that can pose serious threat to the exposed population. Cancer and non-cancer risk of Cr(VI) was higher than other metals in groundwater. The results revealed that the total cancer risk was 1.21E-03 and 1.05E-03 in adults and children, respectively, which exceeded the USEPA acceptable cancer health risk. High health risk was observed through oral intake of water, while both cancer and non-cancer risks were negligible through dermal contact. This study strongly advocates proper periodic assessment of drinking as well as surface water in the area and regulation to restrict the use of contaminated water for daily use.     

Effects of Contaminant Concentration,Aging, and Soil Properties on the Bioaccessibility of Cr(III) and Cr(VI) in Soil

Contaminated soils at numerous U.S. Department of Defense, Department of Energy, and other industrial facilities often contain huge inventories of toxic metals such as chromium. Ingestion of soil by children is often the primary risk factor that drives the need for remediation. Site assessments are typically based solely on total soil-metal concentrations and do not consider the potential for decreased bioaccessibility due to metal sequestration by soil. The objectives of this research are to investigate the effect of soil properties on the bioaccessibility of Cr(III) and Cr(VI) as a function of contaminant concentration and aging. The A and upper B horizons of two well-characterized soils, representative of Cr-contaminated soils in the southeastern United States, were treated with varying concentration of Cr(III) and Cr(VI) and allowed to age. The bioaccessibility of the contaminated soils was measured over a 200-d time period using a physiologically based extraction test (PBET) that was designed to simulate the digestive process of the stomach. The sorption of Cr(III) and Cr(VI) varied significantly as a function of soil type and horizon, and the oxidation state of the contaminant. Solid phase concentrations with Cr(III) were significantly greater than Cr(VI) for any given initial Cr concentration. This is consistent with the mechanisms of Cr(III) vs. Cr(VI) sequestration by the soils, where the formation of Cr(III)-hydroxides can result in the accumulation of large mass fractions of contaminant on mineral surfaces. Overall, Cr bioaccessibility decreased with duration of exposure for all soils and at all solid phase concentrations, with aging effects being more pronounced for Cr(III). The decrease in Cr bioaccessibility was rapid for the first 50 d and then slowed dramatically between 50 and 200 d. In general, the effects of Cr solid phase concentration on bioaccessibility was small, with Cr(III) showing the most pronounced effect; higher solid phase concentrations resulted in a decrease in bioaccessibility. Chemical extraction methods and X-ray Adsorption Spectroscopy analyses suggested that the bioaccessibility of Cr(VI) was significantly influenced by reduction processes catalyzed by soil organic carbon. Soils with sufficient organic carbon had lower Cr bioaccessibility values (～10 to 20%) due to an enhanced reduction of Cr(VI) to Cr(III). In soils where organic carbon was limited and reduction processes were minimal, the bioaccessibility of Cr(VI) dramatically increased (～60 to 70%).     

Arsenic and heavy metals health risk assessment through drinking water consumption in the Peshawar District,Pakistan

This study aimed to assess the drinking water quality and human potential health risk in Peshawar, which is the most populous district of Khyber Pakhtunkhwa Province, Pakistan. Water was randomly collected throughout Peshawar District (urban = 45 samples and rural = 29 samples). These samples were analyzed for heavy metal (As, Cd, Co, Cu, Cr, Hg, Ni, Pb, and Zn) concentrations using the atomic absorption spectrometer (Perkin Elmer, AAS-PEA-700). Heavy metal concentrations in drinking water revealed the highest pollution index (PI) values—17.80, 11.92, 7.50, and 5.70 for the Pb, Cr, Cd, and Ni, respectively. The contaminations of Cd and Pb were significantly higher (p < .05) than their maximum allowable limits set by the World Health Organization. Heavy metal contaminations in drinking water were evaluated for health risk assessment: the chronic risk or hazard quotient (HQ) and cancer risk. Results revealed that HQ values were >1 for the Cd and Pb, suggesting that the exposed human beings could be at chronic risk. Therefore, serious measures such as drinking water treatments and contamination controlling policies are needed to avoid the hazardous effects of toxic heavy metals.     

Evaluation of metal contamination and risk assessment to human health in a coal mine region of India: A case study of the North Karanpura coalfield

The present study aimed to evaluate metal contamination level in coal mine water of the North Karanpura coalfields and assess the possible health risk due to the intake of untreated mine water. Fourteen coal mine water samples were collected from the study area and analyzed for Al, As, Ba, Cr, Cu, Fe, Mn, Ni, Se, and Zn using inductively coupled plasma-mass spectroscopy (ICP-MS). The heavy metal pollution index (HPI) was used to calculate metal pollution level in the coal mine water. The hazard quotient (HQ) and hazard index (HI) were estimated for health risk to child and adult by using the United States Environmental Protection Agency (USEPA) methods. The concentrations of Al, Fe, Mn, and Ni in coal mine water were exceeding the acceptable as well as the maximum permissible limits specified for drinking and domestic uses. The HPI values were below the critical pollution index level of 100 except at one location. The estimated HQ and HI values for adult and children were greater than the standard limits in nearly half of the water samples. High HQ and HI values suggest that suitable treatment of coal mine water will require before its utilization in domestic and drinking purposes.     

Bioavailability of Metals in Soil and Health Risk Assessment for Populations Near an Indian Chromite Mine Area

Soils contaminated with toxic metals may be environmental hazards and sources of exposure to human population. Soils in mining areas are among the most heavily contaminated by metals from the mining activity. This study was focused on metals of interest in bioavailability studies using single and sequential extraction methods. Results of geochemical fractionation suggest that changes in soil characteristics may enhance the mobilization of Cu, Cr, Zn, and Al. The observed metals’ availability pattern was Cr > Cu > Zn > Al. However, the pattern of total contents of metals in soils was Al > Cr > Zn > Cu. Risks to human adults and children from selected metals through soil ingestion was assessed in terms of incremental lifetime average daily dose (LADD), hazard quotient (HQ), and hazard index (HI). The estimated LADDs and HI were within acceptable reference doses and less than 1, respectively, indicating low risk to human populations from the studied metals through soil ingestion in the studied mine area. The generated data may be useful in remediation of contaminated soils with metals.     

Ecological risk assessment of metals in roadside agricultural soils: A modified approach

The threat of metal contamination of roadside agricultural soils poses severe ecological risks throughout the globe due to dual contamination by intensive agriculture and traffic-related activities. Therefore, the present study was conducted to assess ecological risks posed by metals (Cd, Co, Cr, Cu, Fe, Mn, Pb, and Zn) in intensively cultivated roadside agricultural soils of Punjab, India. The results of the contamination assessment factors i.e. Contamination Factor (CF) and Enrichment Factor (EF) indicated that the studied soils were moderately to highly contaminated with metals. It was observed that the Modified Risk Index (MRI), which is based upon EF, indicated the ecological risks of metals more efficiently than the traditional Ecological Risk Index (RI), which is based upon CF in the present study. The MRI values indicated that the metals posed considerable to high risk in 67.86% samples as compared to only 7.14% samples based upon RI values. Thus, MRI can be considered as a more efficient risk indicator in comparison to RI. Spatial distribution maps of MRI indicated to higher metal contamination in inner urban parts of study area due to higher traffic and industrial activities.     

Sources and Ecological Risk Assessment of Heavy Metal(loid)s in Agricultural Soils of Huzhou,China

To identify sources of heavy metal(loid) (HM) contamination in agricultural soils of Huzhou, surface soil samples were sampled from 89 different agricultural regions in 2012. Concentrations of heavy metal(loid)s, along with pH, total phosphorus (TP), total nitrogen (TN), and soil organic matter (SOM), were determined. Ecological risk was then assessed using a modified Hakanson ecological risk index, and the sources of contamination were determined using principal component analysis (PCA). Mean concentrations of heavy metal(loid)s were 10.26, 23.21, 83.75, 22.81, 0.25, 61.86, 33.03, and 0.15 mg kg^?1 for As, Cu, Zn, Ni, Cd, Cr, Pb, and Hg, respectively. Cu, Zn, Ni, Cr, Cd, Hg, and Pb were correlated positively with TP and there were obvious positive correlations among Cu, Zn, Ni, Cr, and Cd. Risk index (RI) values varied from 39 to 1246 with a mean value of 137. Enrichment of Pb, Zn, Cu, and especially Cd can be attributed to excessive use of nitrogen and phosphorus fertilizers containing heavy metals, as well to surface irrigation and natural soil formation. While the ecological risk of most agricultural soils in Huzhou is low, it is recommended that the use of phosphate and nitrogen fertilizers be restricted and production technology be improved to reduce the heavy metal(loid) concentrations. Results suggest that the Chinese environmental quality standard for soil should be revised to better address heavy metal(loid) contamination.     

Fe(III), Cr(VI), and Fe(III) mediated Cr(VI) reduction in alkaline media using a <Emphasis Type="Italic">Halomonas</Emphasis> isolate from Soap Lake,Washington

Hexavalent chromium is one of the most widely distributed environmental contaminants. Given the carcinogenic and mutagenic consequences of Cr(VI) exposure, the release of Cr(VI) into the environment has long been a major concern. While many reports of microbial Cr(VI) reduction are in circulation, very few have demonstrated Cr(VI) reduction under alkaline conditions. Since Cr(VI) exhibits higher mobility in alkaline soils relative to pH neutral soils, and since Cr contamination of alkaline soils is associated with a number of industrial activities, microbial Cr(VI) reduction under alkaline conditions requires attention. Soda lakes are the most stable alkaline environments on earth, and contain a wide diversity of alkaliphilic organisms. In this study, a bacterial isolate belonging to the Halomonas genus was obtained from Soap Lake, a chemically stratified alkaline lake located in central Washington State. The ability of this isolate to reduce Cr(VI) and Fe(III) was assessed under alkaline (pH = 9), anoxic, non-growth conditions with acetate as an electron donor. Metal reduction rates were quantified using Monod kinetics. In addition, Cr(VI) reduction experiments were carried out in the presence of Fe(III) to evaluate the possible enhancement of Cr(VI) reduction rates through electron shuttling mechanisms. While Fe(III) reduction rates were slow compared to previously reported rates, Cr(VI) reduction rates fell within range of previously reported rates.     

Changes in the speciation,partitioning and phytoavailability of chromium induced by organic soil amendments

Abstract

This study investigated the effect of two organic amendments (compost of cattle ruminai content and Sphagnum-moss peat) on the reduction of hexavalent chromium and the distribution of this metal among the main solid phases of a soil with low organic matter content treated with different levels of Cr(VI) (0–2000 mg Cr kg^?1 soil). At the same level of added organic carbon, the peat reduced Cr(VI) added to the soil from 250 to 2000 mg kg^?1, with 100% efficiency. The reduction efficiency of the compost, however, decreased with the increasing dose of Cr(VI) soil. The distribution of Cr between the different soil components was evaluated by a sequential chemical extraction procedure. The concentration of water-soluble and exchangeable Cr decreased with the addition of organic amendments to the soil, whereas Cr increased in the organic fraction. The effect of added organic material on the Cr absorption was examined with two ornamental plants (Melissa officinalis and Begonia semperflorens). The increased Cr(VI) in the soil increased the Cr concentration in plant tissues. The addition of organic matter produced a greater aerial biomass for each level of added Cr in comparison with unamended soil. Sphagnum moss peat was more effective than the compost to decrease the total Cr and the Cr(VI) concentration in the water-soluble and exchangeable fraction of soil, thereby reducing the Cr accumulation in plants tissues and phytotoxic symptoms.