GROUNDWATER QUALITY AND CONTAMINATION INDEX MAPPING IN CHANGCHUN CITY,CHINA

Groundwater in Changchun City, Jilin Province of China tends to be influenced by human activities. Chemical types of groundwater were detected in both shallow and deep groundwater were: HCO3--Ca2+ and HCO3--Ca2+·Mg2+ or HCO3--Mg2+·Ca2+; SO42--Ca2+ and SO42--Ca2+·Mg2+; Cl--Ca2+; and CO32--Na+. The deteriorations of groundwater quality due to the increase of TDS, NO3-+ NO2-(as Nitrogen) and TH contents have been observed from 1991 to 1998. Scatter analyses showed strong positive correlations between Ca2+, Cl-and NO3-ions and weak negative correlations between the depth of water table and Ca2+, SO42-, Cl-and NO3-ions. A mapping of contaminant index based on Chinese standard of groundwater showed that a large proportion of the groundwater in 1998 was deteriorated by human process. Despite their low values of sodium adsorption ratio (SAR), the most of the sampled wells were not suitable for drinking and agriculture purposes due to higher contents of NO3-, NO2-and Mn2+ ions.

Contamination and Ecological Risk Assessment of Heavy Metal in the Sediment of Turag River, Bangladesh: An Index Analysis Approach

Encroachment, disposal of untreated domestic and industrial wastewater and dumping of solid wastes have degraded the overall quality of the river Turag, which is located in Dhaka—the Capital City of Bangladesh. The present study investigated the extent of pollution of sediments of this river and analyzed the regional variability for the concentrations of Cr, Pb, Zn, Cu and Cd—all of concern because of their potential toxicity, using atomic absorption spectrophotometer. As per US EPA sediment quality guideline, metal concentrations ranged between Cd: 0.00 - 0.80, Cr: 32.00 - 75.50, Cu: 46.30 - 60.00, Pb: 28.30 - 36.40, and Zn: 94.60 - 190.10 mg/kg in the Turag river sediments. Cr, Cu, Zn belongs to moderately to highly polluted, Pb and Cd belongs to not polluted for Turag river. The heavy metals contamination in the sediments were also evaluated by applying Index of geo-accumulation (Igeo), contamination factor (Cf), pollution load index (PLI) etc. Toxicity characteristics leaching procedure (TCLP) test (US EPA 1311) for sediment samples have been performed also for metals (Pb, Cd, Cr, Cu and Zn) to determine the readily toxicity level of heavy metals. Sieve analysis of sediment performed in this study to determine the physical characteristic of sediment samples. The metal concentrations are well below the regulated level as per US EPA. This index can be complemented with the contamination index, which allows more site-specific and accurate information on contaminant levels. If the aim of work on contamination evaluation is to assess the overall contamination of a study area, the indices are highly appropriate.

An Assessment of Heavy-Metal Contamination in Soils within Auto-Mechanic Workshops Using Enrichment and Contamination Factors with Geoaccumulation Indexes

Soil characterization and heavy metals in different layers (0 - 15 cm;15 - 30 cm and 30 - 45 cm depth) of automobile mechanic waste dumps were studied. The soils showed remarkably high levels of all the metals above background concentrations with most (Ni, Cu, Fe, Cr and Cd) decreasing with soil depth. The distribution pattern were in the following order Fe > Cu > Zn > Pb > Cr > Ni > Cd. Across all the sampling locations and profiles, Fe and Cd showed the highest (476.4 μg·g-1) and least (37.5 μg·g-1) mean concentrations respectively. Pollution load index (PLI) and index of geoaccumulation (Igeo) revealed overall high and moderate contamination respectively but the enrichment factors (EFs) for Pb Ni and Cd are severe. The inter-element relationship revealed the identical source of elements in the soils of the studied area. The accuracy of the results has been cheeked using the standard reference material;SRM (PACS-2). The mechanic waste dumps represent potential sources of heavy metal pollution to environment. The elevated levels of heavy metals in these soil profiles constitute a serious threat to both surface and groundwater.

Recommended Concentration Limits of Typical Indoor Air Contaminants

From the view of both objective and subjective factors,the indoor air quality(IAQ)evaluation was considered.Carbon dioxide(CO2)and formaldehyde(HCHO)were selected as the typical contaminants of indoor air,and the evaluation method of logarithmic index was adopted as the evaluation means of IAQ.Then the recommended limits(RL)of typical contaminants CO2 and HCHO were given through analysis and calculation.The limits of CO2 and HCHO in Indoor Air Quality Standard of China or other existing standards probably correspond to the level of PD=25(%).The result shows that the existing standards fail to meet the requirement of the definition of "acceptable indoor air quality",that is to say,less than 20% of the people express dissatisfaction.When PD=20%,RL of CO2 and HCHO are 728×10-6 and 0.068×10-6 respectively,which are stricter than the limits in the existing standards.The method proposed in this paper is applicable to 13.1%≤PD≤86.7%.

Development of a Water Quality Index (WQI) of an Artificial Aquatic Ecosystem in Mexico

A Water Quality Index (WQI) is a simple numeric expression reflecting the quality of water in any ecosystem at a given time. The objective of this study was to develop a WQI for the man-made dam Francisco I. Madero located in Chihuahua, Mexico. Eight points were randomly selected in the dam area and at each point water samples were collected monthly from March 2011 to February 2012 at three depths;0.30 m, 5 m and 10 m. The following physical-chemical variables were measured: potential hydrogen (pH), electrical conductivity (EC), dissolved oxygen (DO), temperature (T), turbidity, total dissolved solids (TDS), total hardness (TH) and chlorides (Cl-). In a first step for data analysis, an analysis of variance (ANOVA) was performed for each variable considering a factorial treatment design 12 × 3 in which factor A was the month with 12 levels (sampling months) and factor B was the depth with three levels (0.30 m, 5 m and 10 m). In a second statistical step, the WQI was calculated for each month only for the surface sampling (0.30 m) and the resulting value was classified under three categories;2.5 as excellent water. The results showed the following ranges for single variables: pH of 7.63 - 10.65, EC of 190 - 320 μS·cm-1, DO of 1.30 - 12.1 mg·L-1, T of 11.30°C - 30°C, Turbidity of 0-1, 120 NTU, TDS of 170 - 220 mg·L-1, TH of 240 - 900 mg·L-1 and Cl- of 7.28 - 7034 mg·L-1. The calculated WQI demonstrated that water quality varies seasonally and was classified as poor in the rainy season to good in winter season. We conclude that in general the water from the dam is acceptable and suitable for ecological and a broad spectrum of other purposes.

Predictive value of Hajibandeh index in determining peritoneal contamination in acute abdomen:A cohort study and meta-analysis

BACKGROUND Hajibandeh index(HI),derived from combined levels of C-reactive protein,lactate,neutrophils,lymphocytes and albumin,is a modern predictor of peritoneal contamination and mortality in patients with acute abdominal pathology.AIM To validate the performance of HI in predicting the presence and nature of peritoneal contamination in patients with acute abdominal pathology in a larger cohort study and to synthesis evidence in a systematic review and meta-analysis.METHODS The STROBE guidelines and the PRISMA statement standards were followed to conduct a cohort study(ChiCTR2200056183)and a meta-analysis(CRD420-22306018),respectively.All adult patients undergoing emergency laparotomy for acute abdominal pathology were eligible.The accuracy of the HI was evaluated using receiver operating characteristic(ROC)curve analysis in the cohort study and using weighted summary area under the curve(AUC)under the fixed and random effects modelling in the meta-analysis.The Quality Assessment of Diagnostic Accuracy Studies 2 criteria were used for methodological quality assessment of the included studies.RESULTS A total of 1437 patients were included(700 from the cohort study and 737 from the literature search).ROC curve analysis of the cohort study showed that the AUC of HI for presence of contamination,purulent contamination and feculent contamination were 0.79[95%confidence interval(CI):0.76-0.82,P<0.0001],0.76(95%CI:0.72-0.80,P<0.0001),and 0.83(95%CI:0.79-0.86,P<0.0001),respectively.The meta-analysis showed that the pooled AUC of HI for presence of contamination,purulent contamination and feculent contamination were 0.79(95%CI:0.75-0.83),0.78(95%CI:0.74-0.81),and 0.80(95%CI:0.77-0.83),respectively.CONCLUSION The HI is a strong and accurate predictor of intraperitoneal contamination.Although the available evidence is robust,it is limited to the studies conducted by our evidence synthesis group.We encourage other researchers to validate performance of HI in predicting the presence of intraperitoneal contamination and more importantly in predicting mortality following emergency laparotomy.

Application of Principal Component Analysis, Cluster Analysis, Pollution Index and Geoaccumulation Index in Pollution Assessment with Heavy Metals from Gold Mining Operations, Tanzania

Gold mining is now widely acknowledged as one of the significant sources of soil pollution in developed countries. In developing countries, the sources and levels of soil contamination have not been thoroughly addressed. Thus, this study was intended to determine the source of soil pollution and the level of contamination in the active and closed gold mining areas. The research paper presents the pollution load of heavy metals (lead-Pb, chromium-Cr, cadmium-Cd, copper-Cu, arsenic-As, manganese-Mn, and nickel-Ni) in 90 soil samples collected from the studied sites. Multivariate statistical analysis, including Principal Component Analysis (PCA) and Cluster Analysis (CA), coupled with correlation coefficient analysis, was performed to determine the possible sources of pollution in the study areas. The results indicated that Pb, Cr, Cu and Mn come from different sources than Cd, As and Ni. The results obtained from the metal pollution assessment using the Pollution Index (PI) and the Geoaccumulation Index (Igeo) confirmed that soils in the mining areas were contaminated in the range from moderately through strongly to highly contaminated soils. This study verified that soil contamination in the gold mining areas results from natural and anthropogenic processes. The current study findings would enhance our knowledge regarding the soil contamination level in the mining areas and the source of contamination. It is recommended to use PCA, CA, PI and Igeo to assess and monitor the heavy metal contaminated soil in gold mining areas.

Assessment of Retention Ponds and Its Impacts on Health of Residents in Mogadishu, Somalia: Mixed Methods

The purpose of this study was to evaluate the effects of retention ponds on the environment and population health by analyzing water samples from various ponds in Mogadishu, to determine the prevalence of waterborne illnesses that occur during the rainy season in Mogadishu, and to find out what experts thought about the effects of retention ponds on the environment as well as population health in Mogadishu. Methods: Mixed designs were used in the study. The first design is an exploratory study where samples are taken from different retention ponds in Mogadishu. The second design involves gathering secondary data from the online FSNAU Dashboard regarding the incidence of rainfall and waterborne illnesses including malaria and cholera. Additionally, a cross-sectional survey of expert opinions using questionnaires was the third design. The 10 water samples were taken from retention ponds in Mogadishu as part of the sample size. Data on the fourth month was also gathered using the FNSAU dashboard, and seventy sample sizes were used for the expert self-administered questionnaire for the third design. Excel was used for data analysis in the initial design. While BMI SPSS versions 22 were used to analyze the data from the Self-administered Questionnaire, additional methods were utilized to compute descriptive statistics, such as mean and standard deviation, and to analyze demographic data in a frequency table. Findings: The results show that three samples had unsatisfactory scores (Grade D): Yaqshid (Warshadda Bastada) had a WQI of 80.85, Boondheer (Bondher Pond) had a WQI of 80.64, and Wartanabad (Xamar Jadiid Pond) had a WQI of 80.89. The remaining samples were all rated as fair (grade), which indicates that they ranged from 50 to 75. The months with the largest rainfall already occurred in December, November, and October, when the prevalence of diseases during the rainy season was highest for cholera cases. Although October and December saw a significant number of malaria cases, November did not. Retention ponds’ overall effects on residential environments were evaluated, and the results showed that the standard deviation was 0.802 and the cumulative average mean scores were 4.41 overall. This indicates that the respondents were in agreement that retention ponds in Mogadishu, Somalia, had an effect on residential areas. Recommendation: The study suggested that in order to identify retention pond contamination and create treatment units for its management, the Ministry of Health forms a district-level public health committee. All districts must have a sewer system installed by the local government, and retention ponds must be made easier in order to move waste outside of the city.

Heavy Metal Levels and Ecological Risk in Crude Oil-Contaminated Soils from Okpare-Olomu, Niger Delta, Nigeria

Crude oil spills have inflicted extensive disruption upon the Niger Delta ecosystem, resulting in crop loss and severe environmental damage. Such spills exacerbate heavy metal concentration within soil due to the presence of metallic ions. The Okpare-Olomu community has borne the brunt of crude oil pollution from illicit bunkering, sabotage, and equipment malfunction. This study targets an evaluation of ecological hazards linked to heavy metals (HMs) in crude oil impacted agriculturally soils within Okpare-Olomu in Ughelli South LGA of Delta State. In this study, 24 topsoil samples were obtained from areas affected by crude oil pollution;the heavy metal content was evaluated through atomic absorption spectrometry. The concentration ranges for HMs (mg/kg) in soil were: 24.1 - 23,174 (Cu);0.54 - 37.1 (Cd);9.05 - 54 (Cr);12 - 174 (Ni);18.5 - 8611 (Pb);and 148 - 9078 (Zn) at a soil depth of 0 - 15 cm. Notably, metal concentrations were recorded to be above permissible World Health Organization limits. Predominantly, Zn and Pb recorded higher heavy metal concentration when compared to other heavy metals analysed, notably at sampling points PT7 through PT24. Zinc and Pb contamination exhibited highly significant contamination factors, and contamination severity was evidenced across all sample points, signifying a grave risk level. Pollution load indices indicated pervasive extreme pollution levels. Geoaccumulation indices signaled moderate to strong pollution, mainly by Pb and Zn. Ecological risk assessments revealed variable levels of heavy metal contamination, from low to very high, with potential ecological risk reflecting markedly elevated levels. This study underscores the imperative for soil remediation to rectify ecological imbalances in agriculturally affected soil constituents.

迭置指数法在工业园区地下水污染风险评价中的应用

工业园区作为重要的地下水污染源,以园区为研究对象开展地下水污染风险评价对推进地下水污染防治工作具有重要意义,以四川省西南某工业园区为例,采用迭置指数法对园区地下水污染风险进行评价,并利用地下水硝酸盐浓度与地下水污染风险等级之间的Spearman等级相关系数,对评价结果进行验证。研究结果表明:研究区地下水污染风险整体较低,大部分区域为中、低风险区,高风险区域占比3.24%,在研究区中部、北部零星分布。Spearman等级相关系数ρ=0.81,相关性显著,表明迭置指数法可应用于工业园区地下水污染评价之中。研究结果为降低工业园区地下水污染风险和园区地下水污染防治工作提供了科学依据。

Predictive Study of Trace Metal Pollution of Gold Panning Sites in Birimian Formations: Case of the Yaouré Furrow (Côte d’Ivoire)

The present study was carried out on small-scale gold mining sites in the Yaouré region of Côte d’Ivoire. This region is geologically representative of the Birimian formations (2.1 Ga) of West Africa. The aim is to determine the potentially toxic trace metals (TMEs) generated by these sites, with a view to preventing possible contamination and/or metal pollution of the waters that provide fish products for local populations. To this end, a sampling campaign was carried out, resulting in the collection of 20 mining waste samples analyzed by X-ray fluorescence spectrometry (XRF) and 10 by X-ray diffractometer (XRD). The XRF analysis detected 06 predominant TMEs: arsenic, chromium, copper, nickel, zinc and vanadium. Statistical analysis was carried out to determine the distributions and correlations between these ETMs. To assess contamination and/or pollution levels, the following indices were calculated on the basis of reference concentrations of upper continental crust MTEs: Enrichment Factor, Geo-accumulation Index, Concentration Factor, Degree of contamination and those related to ecological risks. The results of statistical analyses and indices have shown that arsenic and chromium are the most predominant and can be, depending on the chemical form, potentially more toxic. The results of the DRX analysis show the occurrence of several minerals carrying these two MTEs, especially that of a rare mineral, Stenhuggarite, an arsenic oxide linked to hydrothermal veins. The majority of gold mining operations in West Africa are located in the birimian zone, hence the need for environmental monitoring by the relevant authorities, to prevent potential ecological risks to water and possibly health risks via the food chain.

Assessing the Impact of Petrol Service Stations on Selected Physico-Chemical Water Quality Parameters within Port Harcourt Metropolis, Nigeria

This study assessed the impact of petrol service stations on physico-chemical water quality in Port Harcourt metropolis, Rivers State. This threw light on the extent of damage and alteration of water quality in Port Harcourt metropolis as a result of the proliferation of petrol service stations especially the condition of ground and nearby surface water. This serves as a useful tool to government and regulatory authorities for planning especially due to lack of central water supply system in Port Harcourt metropolis. The parameters studied were sampled, measured and analyzed using in situ and other standard methods. Remarkable results above permissible limits of interest for physicochemical parameter analysis revealed pH values from 4.6 to 6.8, electrical conductivity from 0.002 µS/cm to 0.42 µS/cm, salinity from 3 ppm to 4050 ppm, and temperatures from 19.9˚C to 32.6˚C. Total dissolved solids (TDS) varied from 7 ppm to 1000 ppm, biochemical oxygen demand (BOD) from 0.167 mg/L to 2.167 mg/L, chemical oxygen demand (COD) from 0.257 mg/L to 3.253 mg/L, and dissolved oxygen (DO) concentrations from 1.70 mg/L to 4.30 mg/L. Specifically, water samples from NNPC Filling Station (Choba) and Eneka Pond displayed “Poor” water quality with WQI values of 112.003 and 112.076, respectively. Similarly, ALLTEC Filling Station (Eneka) and TOTAL Filling Station (Rumuomasi) had “Poor” water quality with WQI values of 173.707 and 180.946, respectively. In contrast, Excelsis Filling Station (Akpajo) demonstrated “Good” water quality with a WQI of 85.2072, while Total Filling Stations (Slaughter) and Choba River revealed “unsuitable for drinking” water quality with WQI values of 552.461 and 654.601, respectively. Slaughter River also indicated very poor water quality with a WQI of 442.024. The physicochemical and nutrient analyses of the water samples showed that activities of the filling stations within the study area may have polluted groundwater in the environment posing poor aesthetics and great health risk to consumers of the water bodies. The findings underscore the need for immediate remediation efforts and stricter regulatory measures to protect water quality. The study concluded that surface and groundwater near petrol service stations in Port Harcourt are unfit for drinking and irrigation purposes without adequate treatment.

嵩明县上游水库沉积物重金属污染特征及生态风险评估

以嵩明县上游水库沉积物为研究对象,解析水库库尾、库中及闸坝不同区域沉积物8种重金属(Zn、Cu、Cr、Ni、Pb、As、Cd、Hg)的空间分布特征,并运用地累积指数法、潜在生态风险指数法、对重金属的污染特征和生态风险等级进行评估。结果表明:①Cu、Zn、Cr、Cd、Ni、Pb、Hg在上游水库沉积物中呈现不同程度的积累,平均含量分别是背景值的2.14、1.73、1.41、7.57、3.56、1.06、1.90倍,其中Cd的积累最为严重,主要来源于Cd的地球化学性质及农业活动,Hg、Zn、Cr、Ni具有相同来源的可能性较大,来源既有交通也存在工业;②从空间分布看,Cu、Zn、Cr、Ni、Pb、Hg含量分布为库尾>库中>闸坝,Cd为库中>闸坝>库尾,且Cd在库中和闸坝的含量明显高于库尾;③地累积指数表明,Cd是最主要的污染因子,上游水库沉积物中Cd处于中度-重度污染,Ni为中度污染,Cu、Hg、Zn为轻度-中度污染。从潜在生态风险指数来看,Cd在库中和闸坝表现为较强生态风险,在库尾为强生态风险,Hg在库尾为强生态风险,在库中和闸坝为中度生态风险,Cd对RI的贡献最大,达到65.16%,Hg次之,为22.42%。

死端搅拌操作条件下平均膜污染度量指数变化

在死端搅拌微滤膜装置上,采用0.1μm孔径的PES平板微滤膜对酵母悬浮液进行过滤实验。研究瞬时膜污染度量指数(t)和平均膜污染度量指数■在不同操作条件下(搅拌速率、浓度、温度、压力和污染物)的变化规律。结果表明,搅拌速率200 rmp时(t)最小,而■随搅拌速率的增加先增大后降低;在浓度、温度以及压力下,(t)均随时间递增,■随浓度递增。另外,■(酵母悬浮液)>■(活性污泥悬浮液)>■(高岭土悬浮液)则说明在实际过滤过程中,选择2 g/L、25℃和0.08 MPa作为固定操作条件,选择尽可能高搅拌速率和低料液浓度的高岭土悬浮液时的膜污染程度最轻。

徐州市地表水体底泥重金属污染特征研究

文章对徐州市地表水体底泥重金属的污染特征进行了研究。对流经徐州市的四条主要河流和云龙湖的55个底泥采样点的重金属含量进行了测试,并采用单因子污染指数法进行了评价。结果表明,徐州市地表水体除云龙湖之外均不同程度地受到了重金属元素的污染。荆马河污染最为严重,其次是奎河、故黄河、京杭大运河。云龙湖的第五个采样点也受到了Hg的污染。污染元素的种类及污染程度与徐州市的产业结构密切相关。

外来污染物对土壤磷酸酶影响的研究进展

磷酸酶在磷循环中占有重要地位 ,对植物有着非常重要的意义。根据几十年的国内外资料 ,本文概述了重金属、农药、酸沉降以及其他各种外来污染物对土壤磷酸酶的影响 ,并探讨了磷酸酶作为表征土壤污染程度的指标的可行性。土壤磷酸酶与各种污染物的相互作用关系在环境中的应用方面还需进一步研究。

云南不同矿区废弃地土壤肥力与重金属污染评价

取样测定了云南兰坪铅锌矿、开远煤矿、个旧锡矿废弃地土壤的营养元素(N、P、K、有机质)和重金属元素(Pb、Zn、Cu、Ni)的含量,并采用单项污染指数法和综合污染指数法评估了废弃地重金属污染状况。结果表明:(1)3个废弃地土壤肥力水平较低。全N、有效P、速效K,有机质等土壤肥力指标等级大都为Ⅲ和Ⅱ级;全P、全K、碱解N的含量很低,分别为0.015%～0.019%、0.12%～0.46%和4.99～38.05mg·kg-1。3个废弃地土壤肥力大小顺序为煤矿废弃地>锡矿废弃地>铅锌矿废弃地。(2)3个废弃地土壤全Pb22.99￣8816.34mg·kg-1,全Zn57.05￣36995.2mg·kg-1,全Cu60.42￣3339.69mg·kg-1,全Ni124.94￣656.11mg·kg-1;而有效态重金属含量很低,除铅锌矿废弃地有效Pb为166.56mg·kg-1外,其余都<50mg·kg-1。单项污染指数评价结果表明,铅锌矿废弃地污染指数Zn>Pb>Cu>Ni,锡矿废弃地污染指数Cu>Zn>Pb>Ni,且都达到重度污染程度,而煤矿废弃地仅Ni达到中度污染程度。综合污染指数评价结果表明,铅锌矿和锡矿废弃地重金属污染达到重度污染等级,而煤矿废弃地重金属污染为轻度污染等级。

长春市土壤重金属污染特征及其潜在生态风险评价

以长春市区土壤为对象,研究土壤中重金属污染的特征,并采用Hakanson提出的潜在生态危害指数法对土壤中重金属的潜在生态危害进行了评价。结果表明,长春市区土壤重金属污染较重,尤其是铅和镍。污染源的空间差异性引起不同功能区土壤中重金属元素的含量不同。长春市土壤达到轻微生态危害,且铅、铜和锌对土壤生态危害达到轻微生态危害;不同功能区达到生态危害程度的顺序依次是公园>郊区耕地>工业区 >住宅区>开发区。

四川省两名优茶产地土壤重金属元素与茶叶品质关系

以国家土壤环境质量标准(GB15618-1995)中的二级标准和有机茶产地环境条件(NY5199-2002)作为评价标准,采用单因子污染指数法和综合污染指数法对四川省两名优茶产地茶园土壤中的8项重金属元素进行对比,得出茶园A土壤环境明显优于茶园B。结合茶园所采集茶叶样品的感官评价,认为优良的土壤环境可以种植出更优质的茶叶。利用茶园A,B现有数据建立回归模型,可对类似的土壤进行适宜性评价,推断土壤是否适合种植茶叶以及茶叶品质如何。

广东大宝山铁多金属矿废水对河流沿岸土壤的重金属污染

粤北大宝山铁多金属矿开发活动产生的选冶废水未经处理直接排放到横石河水中,给横石河流域沿岸环境带来了严重的危害.对沿岸土壤剖面重金属总量和形态的分析表明,Pb、Zn、Cd、Cu等均存在不同程度的污染.其中,以Cd污染最为严重,Pb、Zn也达到中度污染至强污染.河流水体和土壤的pH值对金属总量和可交换态离子浓度有一定程度的影响.土壤中金属总量、金属可交换态含量随着土壤酸度的变化出现相应的变化.在地处下游地势低平污染严重的上坝村,农田表层土Pb、Zn、Cd、Cu的总量分别达到257.762,350.235,5.083和186.901 mg.kg-1,分别超出国家标准的1.03倍、1.75倍、16.9倍和3.7倍,且污染渗透至土壤的深层,生态环境受到严重的潜在危害.