Contamination Index Values Research Articles

Spatial Distribution of Heavy Metal Contamination in Road Dust Samples from an Urban Environment in Samsun, Türkiye.

Road dust is an environmental pollution indicator created by human activities for urban land use. This study aimed to determine the spatial distribution pattern and degree of trace metals in road dust samples collected from 5 different areas in Samsun city center. The trace metals of Mn, Co, Cd, Cr, Cu, Ni, Pb, and Zn are the most examined contaminants in road dust because their hot-spot areas were mainly associated with high traffic density. Factors governing potential contamination index range values of Co, Cr, and Ni were 0.34-0.62, 0.23-0.78, and 0.24-0.48 as the lowest contamination. However, potential contamination index values of Cu, Pb, and Zn in the main road site were 1.80, 2.32, and 2.84 suggesting that relatively high values were uncontaminated to moderately. Pollution assessment methods were applied to toxic metals and revealed that Samsun city had been affected as uncontaminated to moderately contaminated by anthropogenic emission of heavy metals.

Assessment of Water Resources Pollution Associated with Mining Activities in the Parac Subbasin of the Rimac River

The objective of this study is to evaluate the contamination of water resources in the Parac subbasin. The existing contamination by heavy metals due to the presence of mining companies is of great concern to the population that inhabits the area since health is being affected. A methodology has been used as an integrated approach based on pollution assessment indices. Five surface water samples and seven groundwater samples were collected in the Parac subbasin, in the vicinity of the Tamboraque tailings. Physicochemical parameters and heavy metals (Al, As, Br, Pb, Fe, Cd, Mn, Hg, B, Ni, Cu, and Se) were analyzed. The mean concentrations of Al, As, Ba, Cu, Fe, Pb, and Zn were 0.3 mg/L, 0.02 mg/L, 0.02 mg/L, 0.05 mg/L, 0.8 mg/L, 0.04 mg/L, and 0.12 mg/L respectively. HPI, HEI, and Cd indices were averaged around 1378.5, 134.5, and 126.5 respectively, HPI and Cd values were above 100 as a critical contamination index value, which indicates that the water samples are critically contaminated with respect to the heavy metals studied. The total variance was 88.11% of the water quality with two components according to the ACP analysis. Al, As, Cu, Fe, Pb, Zn, and Mn showed a high positive charge on PC1 (69.68%) while Ba and Mo had a high positive charge on PC2 (18.12%). The intensity of distribution of metals As, Fe, Mn, and Pb in surface and groundwater is an environmental concern and a more complete monitoring network is needed for the sustainable management of water resources.

Microbial utilization of recently fixed, plant-derived organic carbon in shallow Holocene and Pleistocene aquifers in Bangladesh

The presence of dissolved arsenic in shallow aquifers of Bangladesh is widely accepted to require microbial dissimilatory iron-reduction in anoxic aquifers utilizing organic carbon as an electron donor. However, the various potential sources of this carbon, and whether organic carbon sources vary with sediment age (i.e. < 12 kyr-old Holocene vs older Pleistocene sediments) are still poorly understood. To shed light on these questions, natural abundance radiocarbon signatures of in situ microbial phospholipids fatty acids (PLFA), concentrations of sterol biomarkers, and aqueous [Cl-] and [Br-] were compared in two Bangladesh aquifers; a shallow (11–15 m) aquifer low in dissolved arsenic containing oxidized (orange) Pleistocene sands, Dopar Tek (DT), and a shallow (6–21 m) aquifer high in dissolved arsenic containing reduced (grey) Holocene sands, Desert Island (DI). Radiocarbon signatures of PLFA (Δ14CPLFA = −30 to −63 ‰ and +9 to +25 ‰, respectively) indicate microbial utilization of carbon fixed from the atmosphere within the last several decades, the drawdown of which into the shallow portions of both the Pleistocene Dopar Tek and Holocene Desert Island aquifers was likely enhanced by regional pumping activities. Similar results were previously obtained for two other Holocene aquifers in the same region, but to our knowledge this is the first time modern PLFA has been extracted from Pleistocene sediments. At both sites, high proportions of phytosterols, low sewage contamination indices (SCI < 0.7), and generally low Cl/Br ratios (averaging 434 and 544 at Desert Island and Dopar Tek respectively), are consistent with predominantly plant-derived organic carbon inputs. This contrasts with sewage-derived input inferred from higher sewage contamination index values (>0.7) previously observed at the two other shallow Holocene aquifers in the same region. Overall, our observations show that microbial communities within shallow aquifers, including those of Pleistocene age, utilize very recently fixed organic carbon associated with both plant and/or sewage origin. The microbial utilization of organic carbon fixed within the past several decades, likely derived from plants, in the anaerobic Pleistocene, has not, as of yet, led to iron reduction that would be sufficient to increase arsenic concentrations in groundwater. However, the observed microbial utilization of recently fixed carbon within all Bangladesh aquifers studied to date, indicates that pumping enhanced drawdown represents a potential risk to any systems where it might occur.

Assessment of spatio-temporal patterns of water quality in a tropical river by multivariate statistical analysis and water quality index methods

Rivers are facing seasonal as well as long-term changes in their hydro-ecological regime in response to multiple stressors that have affected water quality as well as flow volumes. Ramganga is an important tributary of the Ganga River that provides freshwater to the people of Uttar Pradesh and Uttarakhand. In recent years, industrial discharges, agricultural and municipal wastes and wastewater releases have severely polluted the river throughout its stretch. The contamination index (CI) values at Moradabad in the pre-monsoon, monsoon and post-monsoon seasons were 0.78, 0.86, 0.76-not contaminated, at Bareilly 1.68, 1.65, 1.22-slightly contaminated, at Dabri 2.32, 2.34, 1.76-slightly contaminated while the pollution index (PI) values at Moradabad were 1.76, 2.23, 1.43-slightly contaminated, at Bareilly 4.29, 4.49, 3.95-severely contaminated and at Dabri 13.06, 12.21, 9.49- severely contaminated. The pollutants responsible for high pollution are NH3+, PO4-3, SO4-2, NO2-+NO3- which primarily come from agricultural run-off as the farmers use phosphate, ammonium and sulphate fertilizers and pesticides. The land use type along the banks of the Ramganga in Bareilly and Dabri is primarily dominated by agricultural lands. Hence, the increased CI and PI values at Bareilly and Dabri clearly indicate high agricultural pollution.

TRACE METAL CONTAMINATION AND ITS INDEXING APPROACH FOR SHIVNATH RIVER WATER, C.G., INDIA

The present work is aimed at assessing the trace metal contamination and its indexing approach for Shivnath River, one of the major tributaries of Mahanadi River of Durg, Chhattisgarh with respect to some trace metals like Al, Fe, Mn, Cu and Cr. This enables us to assess whether the quality of water is fit for drinking, irrigation and industrial use or not. For this study samples were collected for 2017 and 2018 in all three seasons and subjecting the samples to a comprehensive selected metal analysis. For the assessment of contamination level in water of the study area the data obtained were statistically analyzed first and then calculated for pollution index (PI), Contamination Index (CI), Heavy Metal Pollution Index (HPI). The mean of HPI values found were 67.22 and 75.12 in summer season of 2017 and 2018 respectively. The CI and PI values were less than 1.0 which indicates the water is not critically polluted with respect to heavy metals. It is due to presence of enough flow rate of River water, the metal concentration from domestic and urban runoff has been diluted rapidly with respect to a very small distance.

Analisis Kandungan Cemaran Bakteri Coliform Pada Air Rendaman Tahu di Pabrik Tahu Wilayah Kalideres Jakarta Barat

Tofu is a food source containing high vegetable protein. Tofu is in great demand by most of the Indonesian people because it contains high nutrition and the price is relatively cheap and affordable. To produce tofu requires good hygiene and sanitation, such as providing clean raw materials and water sources that are free from contamination. To determine whether the water source has been contaminated with microbes or not, the Coliform bacteria indicator in the water sample is used. In testing Coliform bacterial contamination in water or raw materials, the Most Probable Number (MPN) method is used to calculate the amount or level of microbial contamination in determining the quality or quality of water and raw materials by referring to the MPN table. This study aims to determine the level of Coliform bacteria contamination in tofu soaking water in a tofu factory in the Kalideres area of ??West Jakarta. The design of this research is a descriptive laboratory type which was carried out in March-June 2020 at the Indonesian Social Solidarity STIKes Laboratory. Based on the results of the research on the presumptive test, it was found that 1 positive tube was contaminated with Coliform in the KR tofu factory and 3 positive tubes at the DN factory. The presumptive test was continued to confirmatory test and found 5 positive tubes polluted at the DD factory, 2 positive tubes at the KR factory and 3 positive tubes at the DN factory. The positive tube from the confirmation test was calculated for the contamination index value (MPN) and obtained 21000 mpn/ml for the DD factory, 4000 mpn/ml for the KR factory and 9000 mpn/ml for the DN factory. It can be concluded that there is Coliform bacterial contamination in all tofu soaking water samples in 3 tofu factories with the MPN index value having passed the contamination threshold.

A comparative study of data‐dependent acquisition and data‐independent acquisition in proteomics analysis of clinical lung cancer tissues constrained by blood contamination

Proteomics analysis is often troubled by high-abundance proteins in samples such as plasma. However, many surgical tissue samples inevitably have got contaminated with blood before cryopreservation. Selection of an appropriate method to minimize the effect of high-abundance proteins is important for proteomics analysis of blood contaminated tissues. Here, we investigated and compared the abilities of data-independent acquisition (DIA) and data-dependent acquisition (DDA) strategies for the proteomics analysis of blood contaminated clinical tissue samples. Twelve pairs of carcinoma and para-carcinoma tissue samples from lung cancer patients were used for proteomics assays separately by DIA and DDA, and the blood contamination level in samples was evaluated by contamination index (CI). Compared with the DDA strategy, DIA in whole exhibited much better analytical capabilities in proteomics analysis of these samples with more identified protein groups and a higher discovery of differential proteins. With CI value increasing, whether DIA or DDA showed decreasing analysis ability. However, for samples with high CI values, the DIA strategy still shows acceptable analytical capability and indicates better blood pollution resistance than the DDA strategy. Our results implied that for clinical tissue samples, particularly for those contaminated with blood, DIA strategy should be a preferred method in proteomics studies.

Long-term simulation of potentially toxic elements (PTEs) accumulation and breakthrough in infiltration-based stormwater management practices (SMPs)

Stormwater management practices (SMPs) rely on infiltration and adsorption capabilities of soil and vegetative cover to mitigate the harmful impacts of contaminants in stormwater runoff, including potentially toxic elements (PTEs). Under chemical equilibrium conditions, the soil-water distribution coefficient (Kd) quantifies the relationship between the solid and aqueous phase PTE concentrations, and thus the PTE removal efficiency and mobility through the SMP soil layers during the infiltration process. The SMP loading ratio (LR), the ratio of the drainage area to the SMP infiltration area, combined with runoff concentration determines SMP mass loading and is also expected to impact PTE transport. In this study, a simulation model was developed to investigate PTE breakthrough and build-up in SMP media, considering the impacts of Kd and LR. Eight PTEs were simulated (Cl−, Cr, Fe, Zn, Cu, As, Cd, and Pb), and Cl− was the only PTE that showed high mobility and reached the groundwater table (e.g., ~ 1 year for breakthrough). Conversely, other PTEs were effectively immobilized in the top ~60 cm of soil for a simulated lifespan of 20 years. Soil and porewater contaminant indices, as indicators of SMP lifespan, were estimated based on the ratio of PTE porewater and soil concentrations after 20 years to published standards, suggesting the following order of environmental significance (most concern to least): Cl− > Cr > As > Pb > Fe > Cu > Cd > Zn. After 20 years of simulated use, only Cl− pore water concentrations at the groundwater table exceeded regulatory values, with porewater contamination index values of 4 to 7.5. Chloride also exceeded the surficial media soil contamination index, as did As and Cr, though these exceedences were largely associated with media background concentrations. Generally, higher LR and Kd contributed to higher accumulation of PTEs in top layers; however, simulations showed that the combination of low LR and high Kd may result in lower PTE accumulation in the media, such that the PTE concentration in soil may decrease in deeper layers. In these scenarios, a notable fraction of PTE load was adsorbed on top layers and considerably lower PTE concentrations reached the lower layers. Sensitivity analysis revealed that dispersion, infiltration rate, and kinetically-limited sorption did not impact the PTE accumulation and mobility to a practical extent. The results from this simulation may be adapted to various environmental conditions to enhance the design and maintenance of SMPs.

Mercury, arsenic, lead and cadmium in waters of the Singrauli coal mining and power plants industrial zone, Central East India.

The present investigation is an attempt to assess the contamination of heavy metals in the ground and surface water of the Singrauli industrial belt area. Pollution indices like heavy metal index (HPI), contamination index (CD) and heavy metal evaluation index (HEI) are used for the evaluation of heavy metal pollution (arsenic As, mercury Hg, cadmium Cd, and lead Pb). Contour maps are constructed to interpret metal spatial distribution. Further, the land-use/land-cover (LULC) maps for the year 2000, 2010 and 2016 are prepared using Landsat satellite data. A total of 48 water samples (Groundwater (27), Surface water (21)) are analysed for heavy metal concentration. Eighty-eight percent of groundwater and 90% of surface water samples are contaminated with Hg. Similarly, high concentrations of Pb and Cd were found in the samples. Surprisingly, all the water samples have As concentration above the WHO permissible limit of 10ppb. Further, 95% of the samples have an HPI value greater than 100 indicating high heavy metal contamination. CD value denotes contamination of 89% of the samples with heavy metals (As, Hg, Cd, Pb). Through spatial distribution, it can be interpreted that most of the contaminated samples lie near thermal power plants, ash ponds, and coal mines. LULC (land use/land cover) study shows a significant decrease in water bodies by (108km2), agricultural land by (54km2) and bare/fallow land by (51km2) from 2000 to 2016. During these 16years, there has been a fourfold increase in the overburden, a threefold increase in dumping yards, a 2.5 times increase in urban areas, and a twofold increase in mining areas. Both the environment and the water quality are deteriorating at an alarming rate. Such scientific investigations are relevant for risk management studies of potable water. The knowledge acquired from such assessment shall be considered with utmost priority by concerned authority considering degrading water quality in the study area. Hence, this study is applicable for designing action plans and control measures to reduce water resource pollution.

Mineralogy and Geochemistry of Rural Road Dust and Nearby Mine Tailings: A Case of Ignored Pollution Hazard from an Abandoned Mining Site in Semi-arid Zone

Abandoned mine tailings are considered as one of the main sources of potentially toxic elements. Because of the lack of supervision, particularly from small-scale or artisanal mining, abandoned tailings have become part of the natural landscape, especially in rural areas from developing countries. Abandoned mine tailings represent a latent problem in terms of the possible affectations to human health and the environment. An example of this is the small-sized (~ 200 × ~ 300 m) abandoned mine tailings located ~ 500 m south of San Felipe de Jesus town, Sonora, in northwestern Mexico. The mineralogy determined in mine tailings samples consists of divalent hydrated metal sulfates (rozenite, starkeyite, kieserite, szomolnokite and epsomite), trivalent hydrated metal sulfates (coquimbite) and divalent-trivalent hydrated sulfates (copiapite), which are highly soluble efflorescent minerals associated with acid mine drainage. Rozenite was detected in road dust samples, evidencing that dust is dispersed and transported from abandoned residues. In order to assess the possible impact of the tailings (un-oxidized, oxidized, efflorescent minerals), concentrations of potentially toxic elements (total and soluble fractions) in samples from mine tailings, unpaved road soils and road dust from San Felipe de Jesus were determined. Average concentrations (ppm) of potential toxic elements in mine tailings samples ranged from 16,756–1306 (As), 665–98 (Cd), 5691–338 (Cu), 14,162–832 (Pb), 492–82 (Sb), 176,219–8285 (Zn). Enrichment factors determined in mine tailings, agricultural soils and road dust exhibit similar patterns, differing only in level of enrichment, which also confirms the dispersion of potentially toxic elements toward surroundings. Contamination Index (CI) and Hazard Average Quotient (HAQ) were calculated in mine tailings to assess potential contamination associated with potentially toxic elements dispersed by aeolian and/or hydric processes, respectively. The CI values suggest that mine tailing materials have a high potential for polluting soils and sediments. Semi-arid conditions of the region favor the suspension and transport of contaminants, potentially affecting surrounding agricultural fields and population. The HAQ values from efflorescence minerals and mine tailings indicate that potential of toxicity is very high, and might affect the quality of water (groundwater and surficial) in the region. CI and HAQ can provide a good estimation of pollution hazards associated with the abandoned mine tailings in the San Felipe de Jesus area.

Heavy metal contamination and health risk assessment in waste mine water dewatering using phosphate beneficiation processes in Jordan

Phosphate production is one of the major industries in Jordan. Phosphate beneficiation processing consume large quantities of its limited fresh water resources for processes such as washing and flotation. The process of mine water effluents have long been contained with remarkably high levels of heavy metals (e.g., Cd, Cr, Mn, Mo, Ni, Pb, U, V, and Zn), making them toxic for human health and surrounding environemnt. The main objective of this study was to determine the heavy metal contamination in washing mine water of phosphate bed-A1 (WMW-A1) and flotation mine water of phosphate bed-A3 (FMW-A3) of a Jordan phosphate mine (Eshidiya), to assess the health risks associated with oral daily intake and dermal absorption of mine water effluents from phosphate mining process. The results indicated accumulations of Cd, Cr, Li, Mn, Mo, Ni, Pb, U, V, and Zn in the mine water, with lower concentrations than the Jordan standards for discharge of water bodies into streams. In particular, Mn and Cr exhibited high levels of pollution in mine water due to their slightly higher contamination index values (CI). This can be interpreted to variation in geochemical behavior of these metal contents naturally present in francolite mineral phase. Varimax rotated factor analysis, cluster analysis, and correlation analysis revealed that Cd, Cr, Li, Mn, Mo, Ni, Pb, U, V, and Zn in mine water were mainly related to geochemical behavior for francolite mineral phase and clay mineral phase represents the main source of mine water contamination. The hazard quotient (HQ) and hazard index (HI) values were assessed to determine health risk (e.g., non-carcinogenic risk and cancer risk) in case of daily intake and dermal exposure pathways in mine water. The health risk assessment showed that As, Hg, Ni, Pb, and Zn are < 1, indicating non-carcinogenic risk tends to become significant for daily intake and dermal exposure pathways by the mine water. The cancer risk of being exposed to lead through WMW-A1 and FMW-A3 from these sources did not exceed the acceptable risk limits of 1:10,000 for regulatory purposes. Overall, this study provides comparative research on the accumulation, potential health risks and sources of heavy metals in mine water (washing and flotation) beneficiation process in Eshidiya mines, and our findings suggest that, Mn and Cr in both mine water could potentially represent environmental problems.

A multi-method approach to groundwater risk assessment: a case study of a landfill in southern Poland

Estimating groundwater vulnerability to pollution is based on the quantitative and qualitative assessment of the degree of exposure to the pollution. This article attempts to assess groundwater vulnerability to pollution in the area of a complex of landfill sites located in the supply area of one of the important groundwater reservoirs in southern Poland. Two dynamic leaching tests and two static tests were carried out on two different samples of slag from one of the metallurgical landfills during various periods of storage (15 year old waste and freshly deposited waste). Transport equations were based on the data from a column experiment. The advection-dispersion equation for column leaching was employed, which confirmed the simulation parameters through experimentation. The results of the leaching tests on chlorides showed that they are leached from the landfill over a period of ~60–90 years from the moment of depositing the waste. The seepage time for the Quaternary aquifer is 1–7 years and, for the Triassic aquifer, 5–40 years. The Backman’s contamination index (1998) values exceeded 25, while a high threat to groundwater is observed when the contamination index value equals 3. The use of all the aforementioned methods determined the most vulnerable area.

Effects of energy development on wetland plants and macroinvertebrate communities in Prairie Pothole Region wetlands

ABSTRACTEnergy production in the Williston Basin, USA, results in the coproduction of highly saline, sodium chloride-dominated water (brine). The Prairie Pothole Region (PPR) overlies the northeastern portion of the Williston Basin. Although PPR wetlands span a range of salinity, the dominant salt is sodium sulfate, and salinities are much lower than brine. Introduction of brine to wetlands can result in pronounced water-quality changes; however, the ecological effects of such contamination are poorly understood. We examined the effects of brine contamination on primary productivity, emergent macrophyte tissue chemistry, and invertebrate communities from 10 wetlands in the PPR. Based on a recognized Contamination Index (CI) used to identify brine contamination in the PPR, water-quality samples indicated that six wetlands were uncontaminated while four were contaminated. Across this gradient, we observed a significant decrease in above-ground biomass and a significant increase in tissue chloride concentrations of hardstem bulrush (Schoenoplectus acutus) with increased CI values. Additionally, a significant decrease in macroinvertebrate taxonomic richness with increased CI values was observed. These findings provide needed insight on the biological effects of brine contamination on PPR wetlands.

Microbial Colonization of the Peri‐Implant Sulcus and Implant Connection of Implants Restored With Cemented Versus Screw‐Retained Superstructures: A Cross‐Sectional Study

The aim of this study is to investigate peri-implant and intraconnection microflora of healthy implants restored with cemented and screwed superstructures. Patients with two to three implants restored with cemented or screwed restorations and 5 years of follow-up were recruited. Samples were taken from peri-implant sulci, adjacent teeth, and the inner portion of connections. Prevalence of positive sites and bacterial loads for 10 microorganisms were obtained with quantitative real-time polymerase chain reaction. Implant connection permeability to the studied microorganisms was estimated using a standardized bacterial contamination index. Statistical analysis was performed using a generalized estimating equations model, Wald χ(2) test, and the least significant difference test. The final sample consisted of 18 patients (55 implants) in the cemented group and 22 patients (46 implants) in the screw-retained group. Regarding prevalence of positive sites, significant differences between groups were only found for Tannerella forsythia, which was 8.7 times more frequent at peri-implant sulci of cemented than screw-retained prostheses. Bacterial loads of Porphyromonas gingivalis, T. forsythia, Parvimonas micra, and total bacterial load were significantly higher at peri-implant sulci for the cemented group; at the inner portion of connections, values were significantly higher for P. micra and Fusobacterium nucleatum for the screw-retained group. Contamination index values demonstrated higher permeability to most microbes in the cemented group. Internal implant surfaces were microbiologically contaminated for both cemented and screw-retained superstructures. Differences were found between the two methods of prosthetic retention: the cemented group presented significantly higher bacterial loads in the peri-implant sulcus but significantly lower bacterial loads at the inner portion of the implant connection.

Risk assessment of brine contamination to aquatic resources from energy development in glacial drift deposits: Williston Basin, USA

Contamination to aquatic resources from co-produced water (brine) associated with energy development has been documented in the northeastern portion of the Williston Basin; an area mantled by glacial drift. The presence and magnitude of brine contamination can be determined using the contamination index (CI) value from water samples. Recently, the U.S. Geological Survey published a section (~2.59km2) level risk assessment of brine contamination to aquatic resources for Sheridan County, Montana, using oilfield and hydrogeological parameters.Our goal was to improve the Sheridan County assessment (SCA) and evaluate the use of this new Williston Basin assessment (WBA) across 31 counties mantled by glacial drift in the Williston Basin. To determine if the WBA model improved the SCA model, results from both assessments were compared to CI values from 37 surface and groundwater samples collected to evaluate the SCA. The WBA (R2=0.65) outperformed the SCA (R2=0.52) indicating improved model performance. Applicability across the Williston Basin was evaluated by comparing WBA results to CI values from 123 surface water samples collected from 97 sections. Based on the WBA, the majority (83.5%) of sections lacked an oil well and had minimal risk. Sections with one or more oil wells comprised low (8.4%), moderate (6.5%), or high (1.7%) risk areas. The percentage of contaminated water samples, percentage of sections with at least one contaminated sample, and the average CI value of contaminated samples increased from low to high risk indicating applicability across the Williston Basin. Furthermore, the WBA performed better compared to only the contaminated samples (R2=0.62) versus all samples (R2=0.38). This demonstrates that the WBA was successful at identifying sections, but not individual aquatic resources, with an increased risk of contamination; therefore, WBA results can prioritize future sampling within areas of increased risk.

Assessment of contaminated sediment by phosphate fertilizer industrial waste using pollution indices and statistical techniques in the Gulf of Gabes (Tunisia)

On July 2010, 26 surface sediments of the Gulf of Gabes, Tunisia were sampled at depth ranging from 0.5 to 10 m. These specimens were analyzed to determine Al, Cd, Cr, Cu, Pb, Zn, F, P, and N concentrations and total organic carbon contents. The distribution map shows that the high amounts of pollutants are principally located between the commercial harbor and the fishing harbor of Gabes. Measurements of heavy metal contents were carried out using (absorption atomic spectrometer), where the enrichment factor (EF), the geoaccumulation index (Igeo), and the contamination index (CI) are determined. The EF values of all metals were >1.5, corroborate anthropogenic impact on the metal levels in this studied area. However, the Igeo and CI values of Cd and Zn elements indicated that sediments collected from sites at the vicinity of the commercial harbor are very contaminated, although for Pb, Cr, and Cu elements these indices indicated that the same sediments are uncontaminated. Statistical analyses (principal component analysis/factor analysis and matrix correlation) show that heavy metals, fluoride, and phosphorus are resulting from the same anthropogenic source.

A GIS-based vulnerability assessment of brine contamination to aquatic resources from oil and gas development in eastern Sheridan County, Montana

Water (brine) co-produced with oil in the Williston Basin is some of the most saline in the nation. The Prairie Pothole Region (PPR), characterized by glacial sediments and numerous wetlands, covers the northern and eastern portion of the Williston Basin. Sheridan County, Montana, lies within the PPR and has a documented history of brine contamination. Surface water and shallow groundwater in the PPR are saline and sulfate dominated while the deeper brines are much more saline and chloride dominated. A Contamination Index (CI), defined as the ratio of chloride concentration to specific conductance in a water sample, was developed by the Montana Bureau of Mines and Geology to delineate the magnitude of brine contamination in Sheridan County. Values >0.035 indicate contamination.Recently, the U.S. Geological Survey completed a county level geographic information system (GIS)-based vulnerability assessment of brine contamination to aquatic resources in the PPR of the Williston Basin based on the age and density of oil wells, number of wetlands, and stream length per county. To validate and better define this assessment, a similar approach was applied in eastern Sheridan County at a greater level of detail (the 2.59km2 Public Land Survey System section grid) and included surficial geology. Vulnerability assessment scores were calculated for the 780 modeled sections and these scores were divided into ten equal interval bins representing similar probabilities of contamination. Two surface water and two groundwater samples were collected from the section with the greatest acreage of Federal land in each bin. Nineteen of the forty water samples, and at least one water sample from seven of the ten selected sections, had CI values indicating contamination. Additionally, CI values generally increased with increasing vulnerability assessment score, with a stronger correlation for groundwater samples (R2=0.78) than surface water samples (R2=0.53).

Trace element contaminations of roadside soils from two cultivated wetlands after abandonment in a typical plateau lakeshore, China

Total concentrations of As, Cd, Cu, Ni, Pb and Zn were determined in order to assess their changes in contamination levels in roadside soils of long-term abandoned tillage (LAT) belt and short-term abandoned tillage (SAT) belt from a plateau lakeshore of China. Results showed that the mean concentrations of these trace elements except for Cd and Pb were lower than background values. The contamination index values of these trace elements fluctuated and generally decreased with increasing distances from the road in both sampling belts except for Cu and Ni. Both LAT and SAT soils were facing Cd and Pb contamination. The integrated contamination level was more serious in LAT soils compared to SAT soils, with heavy contamination levels at the distances from 5 to 10 m in LAT soils. The effects of the studied rural road on both belts were clearly shown up to 250 m away from the road.

Heavy metal contamination of cultivated wetland soils along a typical plateau lake from southwest China

Topsoil (0–20 cm) samples were collected from four cultivated wetlands including Northern and Western Fields (about 30-year tillage), and Southern and Western Fields (about 20-year tillage) along the Yilong Lake of China in October, 2005. Total concentrations of As, Cr, Cu, Pb, and Zn were determined using the inductively coupled plasma atomic absorption spectrometry in order to assess contamination status in four sampling plots. Results showed that the average concentrations of these heavy metals in Northern and Western Fields were significantly (P < 0.01) higher than those in reference soils, while they were generally lower in Southern and Eastern Fields. All the mean concentrations of heavy metals were lower, except that the average concentrations of As and Cr in Northern Field slightly exceeded the soil quality guidelines. The contamination indices showed low-contamination levels for As, Cu, Pb, and Zn in Northern and Western Fields, while no contamination levels could be observed in Southern and Eastern Fields. As for Cr, they showed moderate-contamination levels in Northern Field, but low or no contamination levels in other three Fields. The integrated contamination index values indicated Northern and Western Fields were moderately contaminated, while Southern and Eastern Fields were less contaminated. The same contamination sources of these heavy metals were identified in these fields using factor- and cluster analysis.

Development of a bio-monitoring system for toxicants in water with fish

A bio-monitoring system for toxicants in water has been developed and verified for actual applications. This system is based on the motionality of five Acheilognathus lanceolata, a fish known to be very sensitive to toxic substances, moving around in an aquarium. Their movements are continuously monitored with a charge coupled device (CCD) camera and analyzed to find and quantify any abnormal behavior in their motional characteristics in comparison with the pre-acquired data. That is, the images of fish captured by a CCD camera are digitalized to identify the location of fish in a constant time interval and the locations of each fish were then analyzed mathematically with a personal computer using the equations proposed to determine the motional characteristics such as floatness, fledness and mobility(agility). These data are then converted by means of fuzzy estimation to an index value, defined as the contamination index (CI), by which the system provides the information about the overall toxic strength of the toxicant in the water flowing into the aquarium. If the fish are exposed to toxicant(s), the CI value will be proportional to the strength of its toxicity. The pilot test was performed in a water treatment plant for six months in order to verify the reproducibility of the system over the unstable conditions such as highly turbid water after rainfall as well as in normal conditions. The test results revealed that this monitoring system has good reproducibility and sensitivity, proving our approach, described in this paper, is reliable. As a result, this approach seems to enable us to make a quick and easy detection of toxic substances contained in water, therefore, this system can be applied to a source of water supply as a toxicant watching system.