首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 859 毫秒
1.
This study was carried out to determine the concentration of heavy metals (Cd, Ni, Pb, Cr, Ni and Zn) in ordinary Portland cement (OPC) produced from the co-processing with hazardous waste in comparison with OPC produced using natural raw materials. The results showed that the concentration of heavy metals in cement produced from natural raw material was in the order of Zn > Pb > Cr > Ni > Cu > Cd. Zn and Cd were the highest and the lowest concentrations, respectively, in cements produced from the co-processing activity. The difference between heavy metals concentrations in OPC produced with and without co-processing was found to be statistically significant. The concentration of heavy metals in the cement produced is generally factory dependent. The human risk assessment associated with the heavy metals for non-carcinogenic and carcinogenic risks has been evaluated. The calculated hazard index (HI) and total lifetime cancer risks (LCR) were lower than the acceptable threshold reference values, HI < 1 and LCR < 1 × 10?4, respectively. Thus, it is anticipated that there is no potential of non-carcinogenic and carcinogenic risks for both adult and children. However, the findings indicated that there is a need for regulatory monitoring. The exposure pathway for both non-carcinogenic and carcinogenic risks are both in the order of ingestion > dermal > inhalation.  相似文献   

2.
Atmospheric pollution from atmospheric particulate matter (APM) deposition is one of the major sources of potential hazardous elements (PHEs) contamination. In this study, 68 total APM samples were collected from the local areas of southern Xi’an (NW China) during the long-term period of the 2001–2012 dust campaign. The chemical fractionation of PHEs (Cr, Cu, Ba, Sr, As, Pb, and Zn), their contamination levels, and ecological health risk were examined. The mobility sequence based on the sums of the first three fractionations of the modified BCR (the European Community Bureau of Reference) sequential extraction stages was: Cu (77.83 %) > Pb (74.50 %) > Zn (55.40) > Sr (52.93) > Ba (40.89) > Cr (30.09) > As (21.59). The contamination levels of APMs from these sites, calculated from the total content indices ICF, were uniformly moderate in degree. The obtained single-metal model MIMERSS (speciation index) values had allowed for classification of elements as a function of their potential ecological risk as As (64.00 mean value) > Pb (43.86) > Sr (37.50) > Cu (11.53) ? Ba (11.32) > Zn (7.68) > Cr (1.88). The results presented that the toxic As posed a moderate to considerable risk; Pb and Sr varied from low to a moderate risk, while others posed low risk. However, a new developed multi-metal model GRIIERMS (speciation index) indicated that the PHEs in most of the APMs posed moderate ecological risk. The result was consistent with that of ICF indexes. Combined with the US Environmental Protection Agency, we developed models of (ingestion, dermal and inhalation) hazard index (HI), children’s health risk due to PHEs exposure from APM was higher than that for adults. Much attention should be paid to the PHE As (HI = 0.864, close to 1) for children. While, carcinogenic risk for adults was higher than that for children. Although cancer risk because of As, Cr and Pb exposure were within an acceptable range, the PHEs exposed to the highest density of the population in residential and educational villages in south of Xi’an would be much more concerned. The moderate ecological risk and the higher risk for children’s health illustrated that special attention has to be taken to the mentioned PHEs from APMs in the local ecosystem, and their health risk impact should continue to be checked carefully. The new developed GRIIERMS index method was to be useful for risk assessment of PHEs combining with their chemical fractionations.  相似文献   

3.
This study investigates the values of pH, total dissolved solids (TDS), elevation, oxidative reduction potential (ORP), temperature, and depth, while the concentrations of Br, and potentially harmful metals (PHMs) such as Cr, Ni, Cd, Mn, Cu, Pb, Co, Zn, and Fe in the groundwater samples. Moreover, geographic information system (GIS), XLSTAT, and IBM SPSS Statistics 20 software were used for spatial distribution modeling, principal component analysis (PCA), cluster analysis (CA), and Quantile-Quantile (Q-Q) plotting to determine groundwater pollution sources, similarity index, and normal distribution reference line for the selected parameters. The mean values of pH, TDS, elevation, ORP, temperature, depth, and Br were 7.2, 322 mg/L, 364 m, 188 mV, 29.6 °C, 70 m, 0.20 mg/L, and PHMs like Cr, Ni, Cd, Mn, Cu, Pb, Co, Zn, and Fe were 0.38, 0.26, 0.08, 0.27, 0.36, 0.22, 0.04, 0.43 and 0.86 mg/L, respectively. PHMs including Cr (89%), Cd (43%), Mn (23%), Pb (79%), Co (20%), and Fe (91%) exceeded the guideline values set by the world health organization (WHO). The significant R2 values of PCA for selected parameters were also determined (0.62, 0.67, 0.78, 0.73, 0.60, 0.87, ?0.50, 0.69, 0.70, 0.74, ?0.50, 0.70, 0.67, 0.79, 0.59, and ?0.55, respectively). PCA revealed three geochemical processes such as geogenic, anthropogenic, and reducing conditions. The mineral phases of Cd(OH)2, Fe(OH)3, FeOOH, Mn3O4, Fe2O3, MnOOH, Pb(OH)2, Mn(OH)2, MnO2, and Zn(OH)2 (?3.7, 3.75, 9.7, ?5.8, 8.9, ?3.6, 2.2, ?4.6, ?7.7, ?0.9, and 0.003, respectively) showed super-saturation and under-saturation conditions. Health risk assessment (HRA) values for PHMs were also calculated and the values of hazard quotient (HQ), and hazard indices (HI) for the entire study area were increased in the following order: Cd>Ni>Cu>Pb>Mn>Zn>Cr. Relatively higher HQ and HI values of Ni, Cd, Pb, and Cu were greater than one showing unsuitability of groundwater for domestic, agriculture, and drinking purposes. The long-term ingestion of groundwater could also cause severe health concerns such as kidney, brain dysfunction, liver, stomach problems, and even cancer.  相似文献   

4.
A total of 113 samples of waste and soil were collected from a site in the state of San Luis Potosi, Mexico, that was occupied for several years by the metallurgical industry. Specific magnetic susceptibility (MS), electrical conductivity (EC) and pH were determined, as well as the total and available concentrations of potentially toxic elements (PTEs) such as As, Cd, Cu, Fe, Pb and Zn, which may cause a health risk for humans, animals and ecosystems, and the concentrations of major ions in aqueous extracts of soils and wastes. The solid phases of the samples were also characterized. The results revealed that the soils and wastes exhibited elevated values of PTEs, MS and EC. For soils these values decreased with increasing distance from the waste storage sites. The MS values were elevated primarily due to the presence of Fe-oxyhydroxides, such as magnetite, hematite and goethite, which contain PTEs in their structure leading to a high correlation between the value of MS and the As, Cd, Fe and Pb contents (r = 0.57–0.91) as well as between the PTEs values (r = 0.68–0.92). The elevated EC values measured in the metallurgical wastes were the result of presence of the sulfate minerals of Ca, Mg and Fe. The pollution index, which indicates the levels of simultaneous toxicity from elements such as As, Cd and Pb, was determined, with extreme hazard zones corresponding to areas that exhibit high MS values (0.91 correlation). In conclusion, MS measurements can be used as an indirect indicator to evaluate the PTE contamination in metallurgical areas, and EC measurements can aid in the identification of pollution sources.  相似文献   

5.
This study investigated the status and distribution patterns of selected heavy metals in roadside soils along Irbid-North Shooneh Highway, Jordan. This highway has experienced a growing number of vehicles that are likely to influence the levels of heavy metals in the surrounding agricultural lands. The average concentrations of Cr, Co, Cd, Cu, Pb, Zn, and Ni were 16.0, 36.0, 11.0, 4.0, 79.0, 122.0, and 60.0 mg/kg, respectively. Cd, Pb, and Co showed average levels that are higher than the average world soil background values. Elevated levels of heavy metals were measured in surface soil layer which decreased with depth, and with distance from the roadway. The contamination factor (CF), pollution load index (PLI), single ecological risk (Ei), potential ecological risk index (PERI), and geo-accumulation index (Igeo) generally indicated that the roadside soils are contaminated with Cd, Pb, and Ni. Heavy metals in soils are of geogenic and anthropogenic origins. Weathering of parent rocks in Wadi Al-Arab catchment is the primary natural source, whereas agrochemicals, vehicle exhausts, degradation of surface wear and paint of vehicles, vehicle wear debris of tire, and brake lining are the main anthropogenic sources of heavy metals.  相似文献   

6.
In Egypt, wastewater has been used for irrigation in areas with fresh water scarcity; however, continuous applications may cause potential risks. Thus, the current study aims to map the spatial distribution of soil contamination and human risks of long-term wastewater irrigation due to the exposure of heavy metals. Soils from nine sites in Al-Qalyubia Governorate, Egypt, were sampled and analyzed. Wastewater irrigation resulted in a buildup of heavy metals in soils compared to Nile fresh water-irrigated soil. The pollution index (PI) showed the decreasing order of Cd?>?Zn?>?Ni?>?Cu?>?Co?>?Pb?>?Cr. The soils were out of the safe domain, as the integrated pollution index of Nemero’s (IPIN) exceeded the safe limit of 0.7. The enrichment factor (EF) exceeded 1.0, proving anthropogenic effects. The geo-accumulation index (Igeo) indicated high threats associated with Cd. The calculated hazard index (HI) indicated that humans exposed to such contaminated soils would have a potential health risk, particularly children. It is recommended to perform a treatment to the wastewater used in irrigation to avoid such threats.  相似文献   

7.
The aim of the present study was to assess the levels of heavy metal contamination in soils and its effects on human health in the northern Telangana, India. Soil samples were collected randomly from 15 sampling stations located in the northern Telangana and analyzed for arsenic (As), chromium (Cr), copper (Cu), zinc (Zn), nickel (Ni), and lead (Pb). The index of geo-accumulation (Igeo), ecological risk index (ERI), hazard quotient (HQ), hazard index (HI), cancer risk (CR), and lifetime cancer risk (LCR) were used to estimate the heavy metal pollution and its consequence to human health. Results indicated that As, Zn, Cu, Pb, and Ni were within recommended limits, while Cr concentration (60 mg/kg) exceeded the maximum recommended limit in 93% of soil samples. The HI values of Cu, Ni, and Zn were all less than the recommended limit of HI?=?1, indicating that there were no non-carcinogenic risks from these elements for children and adults. LCR for As and Cr concentrations of the soils was found higher than the acceptable threshold value of 1.0E?04, indicating significant carcinogenic risk due to higher concentration of these metals in the soils of the study region. The chronic daily intake of the metals is of major concern as their cumulative effect could result in several health complications of children and adults in the region. Therefore, necessary precautions should be taken to eradicate the health risk in the study region.  相似文献   

8.
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。   相似文献   

9.
为支撑雄安新区土地资源科学管理,完善中国土壤污染评价体系,文章以雄安新区某废旧金属冶炼区为研究区开展地质调查,采集541件表层土壤样品,测定了土壤中的Cd、Hg、Pb、As、Cu、Zn、Cr、Ni八种重金属元素的含量和pH,采用主成分分析法研究重金属元素的组合及分布特征,通过单因子指数法、内梅罗综合指数法、地质累积指数法、潜在生态风险评价法和人体健康风险评价法对土壤重金属的污染程度及风险进行评价。结果显示:研究区土壤中Cu、Zn、Cd、Pb元素超标主要受冶炼活动影响,As、Hg元素高值异常主要由受唐河污染的地下水灌溉引起;单因子污染指数超标比例大小顺序为Cd>As>Cu>Zn>Pb>Hg>Cr=Ni;内梅罗综合指数评价结果显示54%的样品达到了污染水平;地质累积指数超标比例大小为Cd>Cu>Pb>As>Zn>Hg>Ni>Cr,Cu、Cd、Zn、Pb、As极重污染比例分别为13.5%、10.2%、9.1%、10.9%、17.2%;Cd和Hg是主要的生态危害元素,Cd中等-强生态危害比例为65.2%,Hg中等-强生态危害比例为71.3%;非致癌风险因子主要为As、Cr、Pb,95.2%样品对儿童的非致癌风险超过了1,29件样品中As对儿童的致癌风险超过10-4,研究区土壤重金属对儿童具有较高的健康风险。  相似文献   

10.
重庆秀山西北部农田土壤重金属生态健康风险评价   总被引:1,自引:0,他引:1       下载免费PDF全文
为了解矿业活动较多的重庆秀山县西北部农田土壤重金属污染状况,采集了表层土壤样品386件,分析测定As、Cd、Cr、Cu、Hg、Ni、Pb、Zn、Mn等9种重金属元素,采用地累积指数法、潜在生态危害指数法和健康风险评估模型,对该区土壤重金属污染程度、生态风险和健康风险进行评估。结果表明,该区农田土壤9种重金属平均值都高于重庆市土壤背景值,呈现不同程度的积累;Cd、Hg明显超出国家农用地土壤污染风险筛选值,超标率分别为75.2%和44.6%。土壤中Hg污染较严重,处于中污染或重污染状态,Mn、As、Cd总体呈轻污染,其余重金属基本无污染。生态风险评价显示,Hg、Cd为主要生态危害元素,Hg以强、很强和极强风险为主,Cd以中等风险为主。人体健康风险评价显示,儿童更易受到重金属污染威胁,重金属对成人不具有非致癌风险,对儿童具有非致癌风险,As、Cr是主要非致癌因子;成人致癌风险在可接受范围内,个别土壤样对儿童具有致癌风险,As致癌风险最大。  相似文献   

11.
为评价某城市规划新区表层土壤质量,利用网格法采集表层土样1000件,分析8种重金属(Cd、 Cu、 Zn、 Ni、Cr、Pb、Hg、As)元素的含量,并分别运用污染负荷指数(PLI)和潜在生态危害指数(RI)评价研究区表层土壤中重金属的污染程度和危害等级。利用克里金插值法研究土壤PLI和RI的空间分布特征。结果表明:研究区内表层土壤重金属平均值均大于中国土壤背景值,Cd、Cu、Ni较为富集。研究区Cd和Cu元素为重度污染,Cd的生态危害性较强,87.90%的土样为重金属轻微污染,60.83%的土样为中等生态危害。污染较为严重和风险较强的地区主要位于研究区西南部河流两岸,Cu和Cd可能受到了人类活动的影响而偏高。  相似文献   

12.
The concentration of trace metals was measured in groundwater samples collected from Malwa region of Punjab, India. The samples were analyzed by using high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS). The results were compared with permissible limits prescribed by various health and environmental protection agencies. The concentrations of trace metals such as Mn, Se, Mo, Cd, Sb and Pb were higher than their respective permissible limits at some sampling sites. The total hazard index (HItotal) (summing the hazard index through ingestion and dermal routes) at all the sampling sites exceeded or nearing unity, indicating the presence of non-carcinogenic health effects from ingestion of groundwater and dermal contact with groundwater. The results reveal that the total excess lifetime cancer risk (ELCRtotal) of metals exposure was in accordance with the acceptable lifetime risks for carcinogens in drinking water.  相似文献   

13.
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健康风险评估模型分别评价该区土壤重金属污染程度、潜在生态风险和人体健康风险。结果表明,该区农田土壤中Cd、Hg、Pb、Cu、Ni、Zn 6种重金属平均值高于潼关县土壤背景值,呈现不同程度的积累;Pb、Hg、Cd的土壤积累含量不仅超出了土壤重金属污染对农产品质量存在安全风险的最低限值农用地土壤污染风险筛选值,还分别以41.2%、72.1%、14.7%的超标率超出了土壤重金属污染对农产品质量存在安全风险的最高限值农用地土壤污染风险管制值;研究区土壤重金属污染评价显示,土壤中Hg、Cd、Pb总体污染程度最重,Cu、Zn总体呈现轻—重污染,Ni、Cr、As总体呈现无污染状态。生态风险评价显示,Hg、Cd、Pb为主要生态危害元素,Hg为极强风险,Cd和Pb为强风险。人体健康风险表明,研究区重金属对儿童的非致癌风险显著,Pb、Hg为主要非致癌因子;致癌风险均在合理范围,Cd致癌风险最大,手-口摄入为最主要的暴露途经,儿童更易受到重金属污染威胁。  相似文献   

14.
Heavy metals are introduced in human tissue through breathing air, food chain and human skin. They can cause damage to the nervous system and internal organs. In the present study, sixty street dust samples were collected from the central area of Tehran and were digested in the laboratory to determine the content of Zn, Ni, Cd, Cr, Cu and Pb, using inductively coupled plasma optical emission spectrometry (ICP-OES). The level of contamination with the analyzed metals was determined according to the following indices: geo-accumulation index (I geo), enrichment factor (EF), pollution index (PI), integrated pollution index (IPI) and potential ecological risk index (RI). The average concentration of heavy metals found was in the order of Zn > Cu > Pb > Ni > Cr > Cd. The average I geo values for Cd, Cr, Cu, Ni, Pb and Zn were 1.53, ?1.88, 2.68, ?0.67, 1.62 and 2.70, respectively. Among the investigated heavy metals, zinc and copper had the maximum average EF values and were placed into the “very severe enrichment” class. Potential ecological risk factor (E r) also indicated that Cd had the highest risk, and it was classified as of considerable potential ecological risk. Therefore, it is necessary to pay more attention to the appearance of Cd in the human environment. The calculated potential ecological risk index values also illustrated that the street dust samples presented a “moderate ecological risk.” The calculated IPI values showed that the pollution levels of the street dust samples ranged from high to extremely high.  相似文献   

15.
A land-use-based method for potential human health risk analysis was introduced by employing soil sampling data in Zhuzhou City, China. It was found that distribution and sources of heavy metals (As, Cd, Pb, Zn and Cr) in soil had a large variation among different land-use types. A total of 8.3 % of the study area recorded a hazard index (HI) above the threshold of 1.0. High HIs were located mainly in the industrial area. The largest contribution to HI was the arsenic (over 87 %) and the pathway of soil ingestion (about 76 %). The mean standardized error and root mean square standardized error indicated that the land-use-based simulation method provided more accurate estimates than the method that applied geostatistical methods to the whole study area and did not consider land-use information. The areas of greater concern for human health can be spatially identified and health risks can be better quantified by evaluation of different land-use types.  相似文献   

16.
This study concerns the mineralogy, spatial distribution and sources of nine heavy metals in surface sediments of the Maharlou saline lake, close to the Shiraz metropolis in southern Iran. The sources for these sediments were studied by comparing the mineralogy and the distribution of heavy metals, using multivariate statistical analysis (correlation analysis and principal component analysis). The geochemical indices, including geo-accumulation index (Igeo), contamination factor (CF) and pollution load index (PLI), were used to assess the degree of heavy metal contamination in surface sediments. Sediment quality guidelines (SQGs) have also been applied to assess its toxicity. The XRD analysis shows that the main minerals of the surface sediments are aragonite, calcite, halite and quartz, with small amounts of montmorillonite, dolomite and sepiolite. The total heavy metal contents in surface sediments decrease in order of Sr?>?Ni?>?Cr?>?Zn?>?Cu?>?Co?>?Pb?>?As >?Cd and the average concentrations of Sr, Ni and As exceeded more than 10, 5 and 3 times, respectively, by comparing with the normalized upper continental crust (UCC) values. The results of pollution indices (Igeo, CF and PLI) revealed that strontium (Sr), nickel (Ni) and arsenic (As) were significantly enriched in those sediments. Based on the sediment quality guidelines (SQGs), Ni would infrequently cause toxicity. Multivariate statistical analysis indicated that the Ni, Co and Cr came mainly from natural geological background sources, while Cd, Cu, Pb, and Zn were derived from urban effluents (especially traffic emissions) and As originated from agriculture activities. Significant relationships of Sr with S, CaO and MgO in sediments suggest that Sr was derived from carbonate- and gypsum-bearing catchment source host rocks.  相似文献   

17.
The total concentrations of Cd, As, Pb, Cr, Ni, Co, Zn, Cu, Ag, Hg, and Mo were determined in the atmospheric dust of the city of Yerevan by atomic absorption spectrometry (AAnalyst PE 800). Heavy metal pollution levels were evaluated by calculating geo-accumulation (I geo ) and summary pollution (Zc) indices. Potential human health risk was assessed using the United States Environmental Protection agency’s human health risk assessment model. The results show that mean contents of all elements tested except Ni and Cr were substantially higher than local geochemical background values. According to the I geo , Yerevan territory is strongly-to-extremely polluted by As, Ag, Hg, Mo, and Cd. The Zc assessment indicated that very high pollution was detected in 36 % of samples, high in 32 %, average in 12 %, and low in 20 %. The health risk assessment revealed a non-carcinogenic risk (HI >1) for children at 13 samplings sites and for adults at one sampling site. For children the risk was due to elevated levels of Mo, Cd, Co, and As, while for adults, only Mo. Carcinogenic risk (>1:1,000,000) of As and Cr via ingestion pathway was observed in 25 and 14 samples, respectively. This study, therefore, is the base for further detailed investigations to organize problematic site remediation and risk reduction measures.  相似文献   

18.
This study presents a diagnostic of the current state of 114 stream sediment samples by their elemental concentrations (Sb, Cd, Pb, As, Cu, Zn, Ni, Cr, and Hg), collected from Ighardayane upstream on an area of 15 km2 located at the SE part of central Morocco where Tourtit and Ichoumellal, two abandoned mining sites of Stibnite, are located. Several approaches were used to model the analysis (i) enrichment factor (EF), (ii) sediment pollution index (IPS), (iii) probable effect concentration-quotients (PEC-Qs), and (iv) potential ecological risk index (PERI). Results show highly contaminated areas around the old mining sites by Sb As, Pb, and Cd. Cadmium and lead show 86.9 and 12.29% (respectively) of trace element pollution according to sediment pollution index. Twenty-eight percent of the sampled area is potentially highly toxic because of the presence of Hg, Pb, and Cd. The very similar distribution of pollution and toxicity of most analyzed trace elements may originate from the same source, which corresponds to mining wastes where we recorded the highest pollution and toxicity degrees. This environmental issue represents the combination of Tourtit and Ichoumellal anthropic sources responsible of Sb, As, Pb, and Cd release and a probable natural source of Hg “that needs a further study,” which contribute in the degradation of an aquatic ecosystem of the same area. Therefore, both ecotoxicological analysis and stream sediment quality management should be carried out to control this aquatic ecosystem toxication.  相似文献   

19.
The concentrations of potential toxic elements (PTEs) such as cadmium (Cd), copper (Cu), lead (Pb) and zinc (Zn) were measured in five different stations of Rameswaram (RM) coast, Gulf of Mannar (GoM), India, in coastal waters in sediments and tissues of Adocia pigmentifera. Concentration of PTEs (Cd, Cu, Pb and Zn) was found to be highest in sediments followed by A. pigmentifera and seawater samples collected from the different stations of RM coast. The pattern of accumulation of PTEs in the three sample types is of the following order Zn < Pb < Cu < Cd. The seasonal variation of these PTEs also followed the same pattern. One-way analysis of variance (ANOVA) with Tukey’s HSD post hoc test has revealed significant differences among stations S1–S4 when compared with the station S5 which is considered as the reference site. Correlation coefficient study showed no significant correlation in the concentration of PTEs in A. pigmentifera, seawater and sediment samples. The concentration of all the PTEs in different sample types has exceeded the FAO/WHO/sediment background values, except for the concentration of Zn in A. pigmentifera and sediment sample, which did not exceed the limits. The contamination factor (CF) and geoaccumulation index (I geo) values indicated significant contamination of PTEs in the sediments from different stations of RM coast, India. Variations found between the sample types during the studies could be due to changes in levels of pollution discharge over time, availability of PTEs for adsorption as well as variations in the sampling season. Increasing urban sprawl and release of effluents both from domestic and industrial sources are the main sources of pollution at RM coast and are the prime reasons for the loss of existing diverse ecosystem.  相似文献   

20.
Soils from urban areas often contain enhanced pseudo-total levels of potentially toxic elements (PTEs). Considering the expanding tendency of urban agricultural practices it is necessary to understand if these contaminants are available for plant uptake and if they pose risks to animal and human health.This study showed that estimates of Daily Intakes (DIs) of Cu, Pb and Zn for grazing animals were above animal Acceptable Daily Intakes (ADIs) at specific sites under the influence of an airport, an oil refinery and near highways with high traffic rates in the “Grande Porto” urban area (Portugal). These results suggest that there is a potential for dietary transfer of contaminants associated with the ingestion of both contaminated soil and feed by cows and sheep at unacceptably high concentrations.Furthermore, results showed that 40% of variability of ryegrass shoot contents of Cu, Pb and Ni; 60% for Ba; 70% for Zn; and 80% for Cd can be significantly (p < 0.01) explained by the variability of the corresponding chemical available pools in soils. Since the chemical available pools of PTEs in urban soils were rather low when compared with the corresponding pseudo-total pools (median 0.1–5%) and even when compared with the corresponding reactive pools it is advised to perform further research on the conditions and time span for the limited availability of PTEs in urban soils, and to determine under which conditions PTEs on reactive forms may become available.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号