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1.
Arsenic derived from mining activity may contaminate water, soil and plant ecosystems resulting in human health and ecotoxicological risks. In this study, exposure assessment of arsenic (As) in soil, spoil, pondwater and plants collected from the areas contaminated by mine tailings and spoils in and around the La Parrilla mine, Caceres province, Spain, was carried out using AAS method. Water solubility, bioavailability and soil–plant transfer coefficients of As and phytoremediation potential of plants were determined. Arsenic concentrations varied from 148 to 2,540 mg/kg in soils of site 1 and from 610 to 1,285 mg/kg in site 2 exceeding the guideline limit for agricultural soil (50 mg/kg). Arsenic concentrations in pond waters varied from 8.8 to 101.4 μg/l. High concentrations of water-soluble As in the soils that ranged from 0.10 to 4.71 mg/kg in site 1 and from 0.46 to 4.75 mg/kg in site 2 exceeded the maximum permitted level of water-soluble As (0.04 mg/kg) in agricultural soils. Arsenic concentrations varied from 0.8 to 149.5 mg/kg dry wt in the plants of site 1 and from 2.0 to 10.0 mg/kg in the plants of site 2. Arsenic concentrations in plants increased in the approximate order: Retama sphaerocarpa < Pteridium aquilinum < Erica australis < Juncus effusus < Phalaris caerulescens < Spergula arvensis in site 1. The soil–plant transfer coefficients for As ranged from 0.001 to 0.21 in site 1 and from 0.004 to 0.016 in site 2. The bioconcentration factor based on water-soluble As of soil varied from 3.2 to 593.9 in the plants of site 1 whereas it varied from 2.1 to 20.7 in the plants of site 2. To our knowledge, this is the first study in Europe to report that the fern species P. aquilinum accumulates extremely low contents of As in its fronds despite high As levels in the soils. Therefore, the S. arvensis, P. caerulescens and J. effusus plant species grown in this area might be used to partly remove the bioavailable toxic As for the purpose of minimization of mining impacts until hypothetical hyperaccumulating and/or transgenic plants could be transplanted for the phytoremediation of As contaminated soils.  相似文献   

2.
Soils from many industrial sites in southeastern USA are contaminated with As because of the application of herbicide containing As2O3. Among those contaminated sites, two industrial sites, FW and BH, which are currently active and of most serious environmental concerns, were selected to characterize the occurrence of As in the contaminated soils and to evaluate its environmental leachability. The soils are both sandy loams with varying mineralogical and organic matter contents. Microwave-assisted acid digestion (EPA method 3051) of the contaminated soils indicated As levels of up to 325 mg/kg and 900 mg/kg (dry weight basis) for FW and BH soils, respectively. However, bulk X-ray powder diffraction (XRD) analysis failed to find any detectable As-bearing phases in either of the studied soil samples. Most of the soil As was observed by scanning electron microscopy, coupled with energy dispersive X-ray spectroscopy (SEM/EDX), to be disseminated on the surfaces of fine-grained soil particles in close association with Al and Fe. A few As-bearing particles were detected in BH soil using electron microprobe analysis (EMPA). Synchrotron micro-XRD and X-ray absorption near-edge structure (XANES) analyses indicated that these As-rich particles were possibly phaunouxite, a mineral similar to calcium arsenate, which could have been formed by natural weathering after the application of As2O3. However, the scarcity of those particles eliminated them from playing any important role in As sequestration.  相似文献   

3.
Arsenic in soil, vegetation and water of a contaminated region   总被引：2，自引：1，他引：1  
Arsenic concentrations of surface waters, soils and plants were surveyed in three contaminated villages of Bijar County. Total arsenic in water samples (4.5 to 280 μg/L) was correlated with electrical conductivity, total dissolved solid, total hardness, alkalinity, chloride, sulphate, bicarbonate, calcium and sodium (p<0.001). Total arsenic in the soils ranged from 105.4 to 1500 mg/kg. Some of the soil factors play an important role in soil arsenic content and its bioavailability for organisms. In general, the arsenic concentrations in plants were low, especially in the most common wild species. Among 13 plant species, the highest mean arsenic concentration was found in leaves of Mentha Longifolia (79.4 mg/kg). Arsenic levels in soils and plants were positively correlated, while the ability of the plants to accumulate the element, expressed by their biological accumulation coefficients and arsenic transfer factors, was independent of the soil arsenic concentration. Relationships between the arsenic concentrations in plants, soils and surface water and the environmental aspects of these relationships have been discussed in comparison with literature data. The accumulation of arsenic in environmental samples (soil, sediment, water, plant, etc.) poses a potential risk to human health due to the transfer of this element in aquatic media, their uptake by plants and subsequent introduction into the food chain.  相似文献   

4.
A field study was carried out to evaluate long-term heavy metal accumulation in the top 20 cm of a Tunisian clayey loam soil amended for four consecutive years with municipal solid waste compost at three levels (0, 40 and 80 t/ha/y). Heavy metals uptake and translocation within wheat plants grown on these soils were also investigated. Compared to untreated soils, compost-amended soils showed significant increases in the content of all measured metals: cadmium, chromium, copper, nickel, lead and zinc in the last three years, especially for plots amended with municipal solid waste compost at 80 t/ha/y. Wheat plants grown on compost-amended soils showed a general increase in metal uptake and translocation, especially for chromium and nickel. This heavy metal uptake was about three folds greater in plots amended at 80 t/ha/y as compared to plots amended at 40 t/ha/y. At the end of the experimental period, the diluting effect resulting from enhanced growth rates of wheat plants due to successive compost applications resulted in lower concentrations in the plants (grain part) grown on treated plots. On the other hand, chromium and nickel were less mobile in the aerial part of wheat plants and were accumulated essentially in root tissues. Plant/soil transfer coefficients for compost-amended treatments were higher than threshold range reported in the literature, indicating that there was an important load/transfer of metal ions from soils to wheat plants.  相似文献   

5.
This study was directed toward a preliminary assessment of nitrate degradation in northeast Iowa soils. Soil experimental plots were created with variable combinations of fertilizers, ethanol, irrigation, and plant growth. The maximum average concentration of nitrate was much higher in the chemically fertilized plots (500 mg/km) than those fertilized organically (120 mg/kg). This was attributed to the excessive ammonia volatilization from the applied cow manure. Soil nitrate dropped from 155 to 50 mg/kg in a matter of 3 weeks in the deep samples of the intermittently irrigated plots. This is because higher soil moisture lowered the oxygen level, which favored denitrification. Although ethanol seemed to have restricted the release of nitrate in the manure-treated plots, the data are not conclusive. The highest degradation of soil-nitrate (lowest recovered 38 mg/kg) was observed in the plots that simultaneously grew corn, received cow manure, and were not irrigated. Soils in these plots were depleted of nitrogen by ammonia volatilization from manure, and through the uptake by corn plants. Nitrification of organic nitrogen to nitrate was restricted in plots that were left without irrigation. Rain events helped nitrification on the surface, but promoted denitrification at depth.  相似文献   

6.
Inorganic arsenic (As) pesticides have been widely used for decades in many countries. However, insufficient data are available on the chemical speciation of inorganic arsenicals in tropical paddy soils. Inorganic As-containing pesticides were used in tropical countries, a few decades ago, however, their fate have not been studied. Hence, the objective of this study was to determine fractionation of inorganic arsenicals and to assess As lability with/without fertilizer application using a static incubation experiment. Eight soils from wet and dry regions of Sri Lanka were amended with 1,000 mg/kg arsenate for this purpose. The FT-IR and XRF results suggested that soils in the wet region were rich in Fe/Al-oxides. Paddy soils in the dry zone showed high As lability. These low-humic gley soils have low Fe/Al oxyhydroxide and alkaline pH. In contrast, the wet zone had soils with higher As retention capacity, high amounts of Fe/Al oxyhydroxide, and acidic pH. Arsenic lability increased considerably 30 days after fertilizer application. Overall, As lability was mainly influenced by soil mineralogical and chemical properties, i.e., Fe/Al oxyhydroxide, pH, organic matter, and fertilizer application.  相似文献   

7.
Consuming edible plants contaminated by heavy metals transferred from soil is an important pathway for human exposure to environmental contaminants. In the past several decades, heavy metal accumulation in contaminated soil has been widely studied; however, few researches investigated the background levels of metals in plants and evaluated the difference in plants grown in soils produced from different parent rocks. In this study, a systemic survey of heavy metal distribution and accumulation in the soil–pepper system was investigated in an unpolluted area, Hainan Island, China. Levels of Cu, Pb, Zn and Cd were measured in soils and pepper fruits from five representative pepper-growing areas with different soil parent rocks (i.e. basalt, granite, sedimentary rock, metamorphic rock and alluvial deposits). Average concentrations of Cu, Pb, Zn and Cd in pepper fruits were 11.52, 0.84, 8.77 and 0.05 mg/kg, respectively. The concentrations of heavy metals in soils are controlled by the parent materials and varied greatly from in different areas. Heavy metal contents in all pepper samples were lower than the Chinese maximum contaminant levels. The relationship between heavy metals in soils and biological absorption coefficient (BAC) of pepper fruits suggests that the uptake ability of pepper for soil metals depends mainly on the physiological mechanism, while in some cases, the soil types and supergene environment are also important.  相似文献   

8.
Riparian soils are periodically flooded, leading to temporarily reducing conditions. Diffusion of O2 through plants into the rhizosphere maintains oxic conditions around roots, thereby promoting trace element fractionation along a redox gradient from the reduced soil matrix towards the oxic rhizosphere. The aim of this study was to determine the distribution and speciation of arsenic around plant roots in a contaminated (170-280 mg/kg As) riparian floodplain soil (gleyic Fluvisol). The analysis of soil thin sections by synchrotron micro-X-ray fluorescence (μ-XRF) spectrometry showed that As and Fe were enriched around roots and that As was closely correlated with Fe. Arsenic contents of three manually separated rhizosphere soil samples from the subsoil were 5-9 times higher than respective bulk As contents. This corresponds to the accumulation of about half of the total As in the subsoil in Fe-enrichments around roots. The speciation of As in the soil was assessed by oxalate extractions at pH 3.0 as well as by X-ray absorption near edge structure (XANES) and extended X-ray fine structure (EXAFS) spectroscopy. More than 77% of the total As was oxalate extractable in all samples. XANES and EXAFS spectra demonstrated that As was predominantly As(V). For the accurate analysis of the EXAFS data with respect to the bonding of As(V) to the Fe- or Al-octahedra of (hydr)oxides and clays, all 3-leg and 4-leg multiple scattering paths within the As(V)O4-tetrahedron were considered in a fully constrained fitting scheme. We found that As(V) was predominantly associated with Fe-(hydr)oxides, and that sorption to Al- and Mn-hydroxides was negligible. The accumulation of As in the rhizosphere may affect As uptake by plants. Regarding the mobility of As, our results suggest that by oxygenation of the rhizosphere, plants attenuate the leaching of As from riparian floodplain soils during periods of high groundwater levels or flooding.  相似文献   

9.
Changes in magnetic and chemical properties of soil during the growth of tomato plants (Lycopersicon esculentum) are examined in this study. The synthetic soils, prepared from sand, topsoil and organic material, were treated with magnetite powder (<5 μm) in order to simulate metal contamination. Six soil treatments were prepared from two soil types: controls, low-contamination and high-contamination treatments (0.01 and 0.05 g of magnetite powder/kg soil, respectively). Overall, the contaminated soils had a greater decrease in magnetic susceptibility (MS) than the controls, and the difference in MS decrease between the treatments was found to be statistically significant for both soil types. Potential reasons for the overall MS decrease were explored, and among them, trace element uptake by plants probably had a minor contribution as the concentration differences of Fe and other trace elements (Ni, Mn) between treatments were not statistically significant. In soils, oxidized and weakly magnetic minerals (maghemite, goethite and hematite) were common after plant growth, when compared with the untreated (background) soil. Such mineral transformations could have contributed to the overall MS decrease. The results show that exposure to Fe contaminants can affect plant growth and suggest that plant growth can measurably change the magnetic properties of their growth media. While the potential variables affecting plant growth were controlled as much as possible, there still remains the potential that biotic and abiotic chemical reactions could have affected the results. Thus, continuous monitoring of the changes in soil magnetic and chemical properties in more complex soil–plant systems is needed.  相似文献   

10.
Ingestion of As – contaminated soil by children is a growing concern in former agricultural lands converted to residential or recreational land use areas. The mobility and bioavailability of As is controlled by its reactions with soil particles. The degree and strength of As retention by soil constituents may vary greatly with time. The present authors hypothesize that aging results in reduced mobility of As thereby decreasing As release and its bioavailability. The present study is aimed at evaluating the effect of aging on soil As fractionation and bioaccessibility in a temperature and humidity-controlled greenhouse setting. The design allowed the evaluation of dynamic interactions between soils, pesticides, water, and plants. Therefore, 4 soil types (Immokalee, Millhopper, Pahokee Muck, and Orelia) were selected based on their potential differences in As reactivity. The soils were amended with the pesticide Na arsenate at two rates. Rice was used as the test crop. Soil samples collected after different time periods (0, 6 months, 1 a and 3 a) were extracted for soil-As forms via a sequential extraction technique. Bioaccessible As was extracted via an in vitro gastrointestinal method. At time 0, most of the extractable As in soil was in the soluble form, resulting in high bioaccessibility. As expected, soluble and exchangeable fractions decreased with time for up to 6 months, but remained constant thereafter. After 3 a of soil–pesticide equilibration, As bioaccessibility was still high in all the soils except for the Pahokee Muck. No significant difference in As bioaccessibility was observed between the soils. Arsenic was present predominantly as As(V) with 5–10% of the total dissolved As being present as As(III). Data obtained suggest that although aging had an impact on the geochemical forms, gastric pH was the sole important factor effecting As bioaccessibility.  相似文献   

11.
不同茶园茶叶氟含量及土壤氟的形态分布   总被引：7，自引：0，他引：7  
通过对我国中西南产茶区12个茶园土壤样品和茶叶样品的采集,探讨了不同茶园茶叶氟含量和茶园土壤氟的形态分布规律。老叶和嫩叶氟含量分别为221～1 504 mg/kg和49.0～602 mg/kg,老叶氟含量是嫩叶的2.5～8.1倍。各形态氟含量随土壤层次加深没有统一变化规律,但各层土壤不同形态氟含量均为残渣态铁锰氧化物态＞有机结合态＞水溶态＞交换态。土壤pH值、有机质含量和阳离子交换量对茶园土壤氟的形态分布有不同程度的影响。老叶和嫩叶氟含量随水溶态氟含量的增加均呈显著增加趋势,但与其他形态氟含量没有显著的相关关系。  相似文献   

12.
Concentrations of trace elements such as As, Ba, Co, Cr, Cu, Ni, Pb, Rb, Sr, V, Y, Zn and Zr were studied in soils to understand metal contamination due to agriculture and geogenic activities in Chinnaeru River Basin, Nalgonda District, India. This area is affected by the geogenic fluoride contamination. The contamination of the soils was assessed on the basis of geoaccumulation index, enrichment factor (EF), contamination factor and degree of contamination. Forty-four soil samples were collected from the agricultural field from the study area from top 10–50 cm layer of soil. Soil samples were analyzed for trace elements using X-ray fluorescence spectrometer. Data revealed that soils in the study area are significantly contaminated, showing high level of toxic elements than normal distribution. The ranges of concentration of Ba (370–1,710 mg/kg), Cr (8.7–543 mg/kg), Cu (7.7–96.6 mg/kg), Ni (5.4–168 mg/kg), Rb (29.6–223 mg/kg), Sr (134–438 mg/kg), Zr (141.2–8,232 mg/kg) and Zn (29–478 mg/kg). The concentration of other elements was similar to the levels in the earth’s crust or pointed to metal depletion in the soil (EF < 1). The high EFs for some trace elements obtained in soil samples show that there is a considerable heavy metal pollution, which could be due to excessive use of fertilizers and pesticides used for agricultural or may be due to natural geogenic processes in the area. Comparative study has been made with other soil-polluted heavy metal areas and its mobility in soil and groundwater has been discussed. A contamination site poses significant environmental hazards for terrestrial and aquatic ecosystems. They are important sources of pollution and may result in ecotoxicological effects on terrestrial, groundwater and aquatic ecosystems.  相似文献   

13.
The high phosphorus levels cause the release of phosphorus from soils, thereby increasing the potential for phosphorus export to adjacent water bodies. The loss of phosphorus from soils to surface waters is a major source of water quality impairment. Therefore, soil phosphorus immobilization seems necessary. In this study, red mud (RM) was employed to immobilize phosphorus in a typical agricultural soil. It was found that phosphorus was effectively immobilized by RM. Batch leaching experiments showed that RM reduced phosphorus release from 14.38 to 2.56 mg/kg when soil was amended with 1% RM. Column leaching experiments showed that RM reduced the total amount of phosphorus released from 36.73 to 18.79 mg/kg during the investigated period. Sequential chemical extraction results indicated that RM amendment transformed H2O-P into more stable fractions. The results suggested that application of RM amendment to soils could significantly immobilize soluble phosphorus, reducing phosphorus release to the environment.  相似文献   

14.
Land disposal of fly ash(FA)and sewage sludge(SS)is a major problem due largely to their potentially harmful constituents.In this paper,a potting experiment was performed to evaluate the effects on the plant growth and to discuss in particular the potential hazard to soils and plants according to the characteristics of heavy metal accumulation and migration when FA and SS are used as the amendments of calcific soil in a limestone mining area. The results showed that the application of FA-SS mixture is capable of accelerating the growth of plants and improving the biomass production at either 1:1 or 1:2 FA-SS mixture:soil(w/w).The highest yields were obtained at 1:1(w/w)mixing ratio.When compared with the Element Background Values of Soils in China,the analysis on heavy metals indicated that the contents of Pb,Cr,Hg,Cd,As,Ni,Cu and Zn in the amended soils came up to the second-class environmental quality standards,only Hg and Cd showed significant accumulation.At the same time, though the metal concentrations in roots were higher than those for the control,the concentrations except Cu,Zn in shoots were lower.And all the heavy metal contents in the plants were substantially lower than the toxicity limits. The results indicated that the combined use of FA and SS at a rational rate of application should pose no danger to both soil and food chain based on the characteristics of the FS and SS,heavy metals and calcific soil.  相似文献   

15.
Theeco environmentalpollutioncausedbyminingdevelopmentisaworldwideproblem ,whichhasarousedever increasingattentionofscientists.Inadditiontovegetationdestructionanderosionofcultivatedlanddirectlycausedbyminingdevelopment,scientistshaveplacedmorefocusontheenvironmentalproblemsinducedbythereleaseofharmfulsubstances ( particularlyheavymetals) .Especiallyundersurfaceconditions,thepiled upminewastes (minetailings)undergoweatheringundertheactionofaseriesofgeochemicalfactorssuchasthemineralogyofmineta…  相似文献   

16.
Plant and soil samples were collected from one uncontaminated and four contaminated sites (in the Dashkasan mining area western Iran). Total and water-soluble arsenic in the soil ranged from 7 to 795 and from 0.007 to 2.32 mg/kg, respectively. The highest arsenic concentration in soil was found at the ore dressing area (up to 1,180 mg/kg) and lowest at an uncontaminated area (up to 11 mg/kg). A total of 49 plant species belonging to 15 families were collected from four sampling sites. A significant positive correlation was detected between the concentrations of arsenic in plant dry matter and those in soils. The highest arsenic concentrations were found in Hyoscyamus kurdicus Bornm. (up to 205 mg/kg) and Helichrysum oligocephalum DC. (up to 162 mg/kg). These two accumulator species could have potential for soil clean-up by phytoextraction. The data have been compared with those for the Zarshuran mining area (north-western Iran) obtained in a former study.  相似文献   

17.
Oil fields present a potential ecological risk to nearby farmland soil. Here we present a new method designed to evaluate the ability of winter wheat (Triticum aestivum) to contribute to the dissipation of polycyclic aromatic hydrocarbons (PAHs), which are priority pollutants in soils contaminated by oily sludge. The influence of different doses of oily sludge on the dissipation of PAHs was studied along with individual PAH profiles in soils after different periods of plant growth. Five soil samples were artificially contaminated with different percentages of oily sludge (0 %, 5 %, 10 %, 15 % and 20 %). Winter wheat grew in the oily sludge–amended soils for 265 days. PAH content in the soils was monitored over the course of the study. The rate of PAH dissipation is related to the properties of different PAHs, period of winter wheat growth, and oily sludge application dose. Analysis for treated soils indicates that the dissipation of PAHs increased significantly over the first 212 days, followed by minimal changes over the final 53 days of treatment. In contrast, PAH dissipation slowed with increasing oily sludge application. For each PAH, the experimental results showed a significant compound-dependent trend. Winter wheat in the present study significantly enhanced the dissipation of PAHs in oily sludge–contaminated soil.  相似文献   

18.
The application of As-based herbicides at several industrial sites has resulted in numerous localized areas of As-contaminated soil. In this study, an As-contaminated soil (As = 278 mg/kg) collected from an industrial site located in the southeastern USA was subjected to inorganic phosphate (Pi) treatments. Although Pi treatments have been previously used for flushing As from contaminated soils, in this study, contaminated soil was amended with Pi to study the possible immobilization of As through a co-precipitation mechanism. Specifically, the Pi amendment was aimed at simultaneous flushing of As from the soil with orthophosphoric acid and co-precipitating it as Ca–phosphate–arsenate phases. Bench-scale Pi treatment experiments were performed at different pH conditions, with and without the addition of Ca. Sorption of Pi on BH soil in the presence or absence of additional Ca was determined, along with the associated mobilization of As from the soil. A significant amount of the HNO3-digestible As (up to 55% at pH 4, 10–15% at pH 8, and ∼30% at pH 11) was released from the contaminated soil during the Pi sorption experiments. This increased mobility of As after the addition of Pi resulted from the competitive desorption of As from the soil. Although Pi sorption at high pH (>8) was largely controlled by precipitation, As did not co-precipitate with Pi. Aqueous geochemical modeling indicated that the lack of As co-precipitation during Pi-only treatment primarily resulted from the deficiency of Ca in the system. When additional Ca (16.9 mmol) was supplied along with Pi (3.38 mmol), the mobility of As decreased significantly at circum-neutral to high solution pH. Geochemical modeling suggested that the leachable As in the soil was potentially precipitated as As-bearing Ca–Pi phases. X-ray diffraction analysis of precipitates separated from the treated soil and from the synthetic leachate confirmed that the formation of a poorly crystalline carbonate apatite phase occurred as a consequence of the treatment. The results of this study support the potential application of Ca–Pi treatment for remediation of As-contaminated soil at environmentally relevant pH conditions.  相似文献   

19.
Pot trials and tests in outside plots were carried out on the South African Ni hyperaccumulator plant Berkheya coddii in order to establish its potential for phytoremediation of contaminated soils and for phytomining of Ni. Outside trial plots showed that a dry biomass of 22 t/ha could be achieved after moderate fertilisation. Pot trials with varying soil amendments with nitrogen and phosphorus fertilisers showed enhanced uptake of Ni with increasing nitrogen addition, though there was no reaction to phosphorus. The Ni content of the plant was directly related to the ammonium acetate extractable fraction of Ni in a wide range of natural and artificial substrates. Excision of shoots induced a dramatic increase in the Ni content in the new growth (5500 μg/g compared with 1800 μg/g Ni). When plants were grown in pots with Ni added to the substrate (0–1%), the Ni content of the plants rose to a maximum value of about 1% dry mass. The data from this last experiment were used to calculate the probable Ni yield (kg/ha) of plants grown in nickel-rich soils in different parts of the world. It was calculated that moderately contaminated soils (100 μg/g Ni) could be remediated with only two crops of Berkheya coddii. The potential of this species for phytomining has also been evaluated and it is proposed that a yield of 100 kg/ha of Ni should be achievable at many sites worldwide. Phytomining is also discussed in general terms for other metals as well as Ni.  相似文献   

20.
The Zlata Idka village is a typical mountainous settlement. As a consequence of more than 500 years of mining activity, its environment has been extensively affected by pollution from potentially toxic elements. This paper presents the results of an environmental-geochemical and health research in the Zlata Idka village, Slovakia. Geochemical analysis indicates that arsenic (As) and antimony (Sb) are enriched in soils, groundwater, surface water and stream sediments. The average As and Sb contents are 892 mg/kg and 818 mg/kg in soils, 195 mg/kg and 249 mg/kg in stream sediments, 0.028 mg/l and 0.021 mg/l in groundwater and 0.024 mg/l and 0.034 mg/l in surface water. Arsenic and Sb concentrations exceed upper permissible limits in locally grown vegetables. Within the epidemiological research the As and Sb contents in human tissues and fluids have been observed (blood, urine, nails and hair) in approximately one third of the village’s population (120 respondents). The average As and Sb concentrations were 16.3 μg/l and 3.8 μg/l in blood, 15.8 μg/l and 18.8 μg/l in urine, 3,179 μg/kg and 1,140 μg/kg in nails and 379 μg/kg and 357 μg/kg in hair. These concentrations are comparatively much higher than the average population. Health risk calculations for the ingestion of soil, water, and vegetables indicates a very high carcinogenic risk (>1/1,000) for as content in soil and water. The hazard quotient [HQ=average daily dose (ADD)/reference dose (RfD)] calculation method indicates a HQ>1 for groundwater As and Sb concentrations.  相似文献   

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