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This paper examined the efficiency of artificial neural network (ANN) and multivariate linear regression (MLR) models in the prediction of groundwater quality parameters such as ecological risk index (ERI), pollution load index (PLI), metal pollution index (MPI), Nemerow pollution index (NPI), and geoaccumulation index (Igeo). Forty groundwater samples were collected systematically and analyzed for mainly heavy metals. Results revealed that adopting measured parameters is effective in modeling the parameters with a high level of accuracy. Contamination factor results reveal that Ni, Zn, Pb, Cd, and Cu have relatively low values < 1 within the region while the iron values ranged from low contamination to very high contamination (> 6). PLI, MPI, and ERI results indicated low pollution. NPI results indicated that the majority of the samples were heavily polluted. Quantification of contamination results revealed that most of the sample's quality was geogenically influenced. Igeo results revealed that most of the samples had extreme pollution. The health risk assessment results revealed that children are substantially prone to more health risk more than adults. The ANN and MLR models showed a high effective tendency in the prediction of ERI, PLI, MPI, NPI, and Igeo. Principal component analysis results showed appreciable variable loadings while the correlation matrix results reveal that there exists weak and positive correlation among elements. Based on the outcome of this study, this research recommends the use of ANN and MLR models in the prediction of groundwater quality parameters as they yielded positive, reliable, acceptable, and appropriate accuracy performances. [ABSTRACT FROM AUTHOR]

Exploitation of mines can lead to the entrance of heavy metals into the environment. There is a possibility of water, soil, and plant pollution in Darreh Zereshk area in the near future. To assess the soil contamination and determine the origin of selected heavy metals, enrichment factor (EF) and geoaccumulation index (Igeo) accompanied with principle factor analysis (PCA) and map of spatial distribution of the elements were conducted. A total of 30 agricultural soil samples and 12 background soil samples were collected from Darreh Zereshk area in central Iran which is going to be one of the richest copper mines in Iran and the Middle East. Total and soluble concentration of heavy metals (Cu, Pb, Zn, Mn, As, Fe, Ni, and Cr) and some physico-chemical properties of soils were determined. The results showed that contamination of the agricultural soils is more severe for Pb, Cu, and Zn and less severe for As. The origin of Ni and Cr did not seem to be anthropogenic. The average concentration of Cu, Pb, Zn, Mn, As, Fe, Ni, and Cr in agricultural soils of the area were 36.87 mg/kg, 190.78 mg/kg, 170.33 mg/kg, 367.41 mg/kg, 69.42 mg/kg, 15494.1 mg/kg, 29.25 mg/kg, and 25.01 mg/kg, respectively. Since the Fe and Mn with geogenic origin were located in the same component with Cu, Zn, Pb, and As; it can be inferred that the source of these elements is controlled by both parent material of soil and anthropic activity. [ABSTRACT FROM AUTHOR]

Cement's dust particles contamination on soil has received a good amount of attention due to toxicity persistence in the environment. It must be noted that cement dust falls are enriched in toxic heavy metals, which can spread throughout a large area by wind and rain then accumulate on plants, animals, and soils, thus ultimately affecting human health. For this purpose, a study was achieved to evaluate the potential accumulation and spatial distribution of heavy metals in topsoils surrounding the Meftah cement factory, situated at the southeastern of Algiers region. Sixty six soil samples were collected following six directions (east, northeast, north, northwest, west, and southwest) from cement factory on a radius of 3.5 km approximately. The physicochemical parameters, such as the pH, the conductivity, and the organic matter of these samples were determined. The concentration of the Cd, Cu, Pb, and Zn elements, in soil samples, were determined with flame atomic absorption spectrophotometry (FAAS) method and the data generated were analyzed statistically. Thus, the enrichment factor (EF), pollution index (PI), contamination factor (CF), pollution load index (PLI), geoaccumulation index (Igeo), and principal component analysis (PCA) was performed to the dataset in order to calculate and estimate the enrichment of metal concentrations in soils. Moreover, mapping of the spatial distribution of heavy metals was carried out using geographic information system (GIS), to determine more polluted areas and accomplish the objectives of the study. The results of our analysis indicate that soils were polluted most significantly by metals such as lead, zinc, copper, and cadmium. It is thus important to keep systematic and continuous monitoring of the bag filter to reduce the cement dust emission. As possible, remediation activities be carried out on the soil of heavy metals and their derivatives to manage and suppress such pollution. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the concentration of Pb, Zn, Cu, Cd, Cr, and Fe in sediments of the Ichkeul Lake and rivers ecosystem in northern Tunisia; their comparison with international sediment quality criteria was also proposed to assess the extent of metal pollution and their origin using various pollution indicators. For this purpose, sediment samples were collected in thirteen locations and characterized for metal content (Pb, Cr, Zn, Cu, Cd, and Fe) using the total digestion technique. Pollution level was assessed via the geoaccumulation index (Igeo), enrichment factor (EF), contamination factor (C ), potential ecological risk (PER), and pollution load index (PLI). Our results showed that all metals were lower than the threshold effect levels (TEL), the effect range low (ERL), the probable effect level (PEL), the effect range median (ERM), and the probable effect concentration (PEC) value, except Pb and Cr (higher than TEL), the threshold effect concentration (TEC), and the toxicity reference value (TRV). The geoaccumulation index (Igeo) indicated no pollution for Cr, Cu, Zn, and Fe, but moderate pollution for Pb. The enrichment factor showed no enrichment for most of the studied metals. This was further confirmed by the contamination factor that indicated low contamination levels, with the exception of Pb. The pollution load index (PLI) showed moderate pollution status in all the studied stations in the Ichkeul Lake and rivers ecosystem. The statistical results presented similar trends of Zn and Pb probably due to their similar pollution sources. It was found that the Ichkeul Lake and river ecosystems are characterized by moderate pollution status in all the studied sites except for that of a feeder river drained from an old lead mine which had relatively high metallic concentrations of Pb and Cd. It can be argued that effective remediation strategies and environmental management plans are required to control and reduce the input of environmentally hazardous toxic pollutants (Cd and Pb). This study may serve as a useful reference tool pertinent to approaches to the remediation of the old lead mine area surrounding the Ichkeul Lake as well as other areas under similar ecological conditions.. [ABSTRACT FROM AUTHOR]

The present study was undertaken for assessing the level of heavy metals such as iron, copper, zinc, lead, and cadmium in surface sediment samples of the coast of Ain Temouchent (north-western of Algeria). Sediment samples were obtained from Zouanif, Rachgoun, Beni saf, and Sidi ali during a period between March 2012 and February 2013. The samples were digested using a mixture of acids and the metal content determined using atomic absorption spectrophotometer (AAS). Heavy metal concentrations in sediments show significant variability and ranges from 16.30 to 32.15 mg/g for Fe, 12.49-31.25 mg/kg for Cu, 120.17-193.31 mg/kg for Zn, 25.94-57.27 mg/kg for Pb, and 1.45-16.84 mg/kg for Cd. The results revealed relatively high metallic concentrations of Zn, Pb, and Cd in sediments at the four stations and exceed the background values. The sediment pollution assessments were carried out using a geoaccumulation index ( I ) and enrichment factor ( EF). The results of geoaccumulation index reveal that sediments are uncontaminated with Fe and Cu, uncontaminated to moderately contaminated with Zn and Pb, and moderately contaminated with Cd. The calculation of enrichment factors showed that Cu is depleted, whereas Zn and Pb are moderately and Cd is severely enriched. Metal concentrations were significantly high between stations. Industrial and agricultural activities and a nearby municipal dumpsite were associated with the higher elemental concentrations particularly at Rachgoun and Beni saf. ANOVA test was used to compare the levels of the metals in different stations (inter-station comparison). Principal component analysis (PCA) was applied to investigate the sources affecting surface sediment samples at the stations. [ABSTRACT FROM AUTHOR]

Surface sediments collected at the Tirumalairajan river estuary and their surrounding coastal areas were analyzed for the bulk metal concentration. The sediments were collected from post- and premonsoon seasons. Dominances of heavy metals are in the following order: Fe > Mn > Zn > Pb > Cu in both seasons from estuary and coastal area. The results reveal that Fe, Mn, Cu, Pb, and Zn demonstrated an increased pattern from the estuary when compared to the coastal area. The heavy metal pattern of the sediments of the Tirumalairajan river estuary and its surrounding coastal area offered strong evidence that the coastal area was a major source of heavy metals to the estuarine region. For various metals, the contamination factor and geoaccumulation index ( I) have been calculated to assess the degree of pollution in sediments. The contamination factor and geoaccumulation index show that Zn, Pb, and Cu unpolluted to moderately pollute the sediments in estuarine part. This study shows the major sources of metal contamination in catchment and anthropogenic ones, such as agriculture runoff, discharge of industrial wastewater, and municipal sewage through the estuary and adjoining coastal area. [ABSTRACT FROM AUTHOR]

Mangrove areas are important to the ecosystem. One of its crucial functions is as a sink of pollutants, especially metal ions. However, the accumulation of metals in mangrove sediment can generate negative impacts on plant growth, microbial activity, and soil fertility. Apart from that, the severity of the impact is highly influenced by the type of metal found in the sediment and the quality of sediment itself. One of the metals that have adverse effects on the environment is mercury. The objectives of this study are to determine the concentration and distribution of mercury and to assess the enrichment of mercury in Port Klang mangrove sediment by using geoaccumulation index and enrichment factor. Sediment samples were collected from 30 sampling points that cover Langat River and Klang River estuaries, Lumut Straits, Pulau Klang, and Pulau Indah. During sampling, water parameters such as pH, salinity, electrical conductivity, and total dissolved solids were measured in situ, whereas the total mercury in sediment samples was determined at the laboratory using inductively coupled plasma mass spectrometry. In this study, mercury was found to be concentrated along Lumut Strait especially in the mixing zone near the confluence of Langat River and at the jetty to Pulau Ketam. The geoaccumulation index and enrichment factor (calculated using logarithmized data of the reference element) found that three stations were enriched with mercury. In addition, geoaccumulation index was also observed to be more objective compared to enrichment factor whose results were influenced by the concentration of reference element used. [ABSTRACT FROM AUTHOR]

The study focuses on the lateral distribution and the environmental geochemistry of seven heavy metals: Fe, Mn, Cu, Co, Ni, Pb, and Zn in addition to Al in the stream sediments of Wadi Allaqi. Forty-two samples were collected from the upstream, the midstream, and the downstream of this Wadi. Results of the grain size analysis show that the sediments of Wadi Allaqi are fine to medium sand. The heavy metals content reflects the weathering impact on the hinterland. The highest concentrations of Fe, Al, Mn, Cu, Pb, and Zn are recorded in the midstream that is dominated by clastics of felsic and intermediate composition. Moreover, the downstream, occupied by ultrabasic-basic rocks, shows the highest averages of Co and Ni. These results suggest that the felsic and intermediate rocks are the main source of the former metals, whereas the ultrabasic-basic rocks are the source of later two metals. All the analyzed heavy metals have average concentrations lower than their backgrounds, except for Co and Pb. The pollution level by these heavy metals has been evaluated using enrichment ratio (ER), pollution load index (PLI), and index of geoaccumulation (Igeo). The calculated values of ER, CF, PLI, and Igeo indicate that Wadi Allaqi sediments are almost pristine except occasional feeble pollution level by Co and Pb. [ABSTRACT FROM AUTHOR]