Pollution Load Index Values Research Articles

Assessment of traces metals in sediment from Ebolowa Municipal Lake basin (central-africa): potential risk and provenance

This study focused on assessing contamination levels of heavy metal elements (Cr, Co, Ni, Zn, Cu, Mo, Cd, and Pb) in surface sediments for the Ebolowa Municipal Lake (EML) basin in Southern Cameroon and identifying possible pollution sources. Twenty-one samples from the EML and its tributaries (Mfoumou and Bengo'o) were subjected to geochemical analysis by inductively coupled plasma-mass spectrometry (ICP-MS). The results obtained from these analyses allowed us to calculate the Contamination factor (CF), enrichment factor (EF), geo-accumulation index (Igeo), Potential Ecological Risk Factor (Er), Pollution Load Index (PLI), and Potentiel Ecological Risk Index (RI). Multivariate statistics completed these analyses. The concentrations in mg/kg are as follows: Cr (96.46) > Zn (55.94) > Cu(34.01) > Ni(30.77) > Co(16.14) > Pb(10.58) > Mo (0.61) > Cd (0.14). However, these concentrations are higher in the sites subjected to the most anthropogenic pressure (EML and Mfoumou). The pollution indexes are between: 0.29 ≤ CF ≤ 2.76, -28.10 ≤ Igeo≤0.13, 0.14 ≤ EF ≤ 2.19. PLI values ˂ 1 in all sites. Er has high values for Cd (21.43–42.85) and low values for the other elements. RI ˂ 100 values for all elements and on all sites. Pearson's correlation matrix and the Hierarchical Classification Ascending (HCA) illustrate two sources of inputs. The spatial distribution of TME seems to be impacted by autochthonous inputs of domestic effluents and parameters such as particle size and organic matter content. The pollution index values illustrate low to moderate contamination and pollution in Cr, Ni, Co, Cd, and Cu. The Er values illustrate a moderate ecological risk for Cd. The RI values indicate a low ecological risk for all sites. High values are mainly associated with poor domestic waste management, non-compliant automotive buildings and agricultural activities.

Bioavailability and health risk of toxic heavy metals (As, Hg, Pb and Cd) in urban soils: A Monte Carlo simulation approach

Toxic heavy metals pollution in urban soil has become a major global issue due to its adverse effects on the environment and human health. In this paper, 26 soil samples were analyzed to assess the speciation, bioavailability and human health risk of Arsenic (As), Mercury (Hg), Lead (Pb) and Cadmium (Cd) in urban soils of a heavy industrial city in NE China by using a Monte Carlo simulation approach. The results showed that As, Hg, Pb and Cd concentrations in the soil all exceed the corresponding background value of study area. Mercury displays the highest value of geo-accumulation index (Igeo), followed by Cd, Pb and As. The pollution load index (PLI) value (>2) indicates a moderate pollution level in the study area. The chemical speciation of HMs mainly exists in residual fraction except Cd. The probabilistic health risk assessment demonstrated that the mean values of Total Carcinogenic Risk (TCR) and Hazard Index (HI) calculated with total concentration are at the unacceptable level, with a higher risk to children than adults. However, the mean values calculated with bioavailable fraction are all within the acceptable level. The mean value of TCR and HI obtained by bioavailable fraction is about 96% and 95% lower than that obtained by total concentration, respectively. Thus, this study suggested that the bioavailable fraction of HMs is a more reliable parameter for health risk assessment, while the total concentration of HMs can overestimate the true risk. The results of this study provide some insight into the speciation, bioavailability and health risks of toxic heavy metals in urban soils in those heavy industrial cities.

Hydrogeochemical assessment of groundwater quality: a case study of Federal College of Education (Technical), Omoku, Rivers State

Abstract This study was carried out to assess the suitability of groundwater for drinking and irrigation purposes by interpreting the hydrochemical species of groundwater samples. Six water samples were collected and assess to determine the concentration of some ions, pollution load index (PLI), contamination factor (CF), water quality index (WQI), sodium adsorption ratio (SAR), magnesium hazard (MH), Kelly ratio (KR) and percentage sodium (%Na). The result revealed that most of the ions have concentrations within the WHO permissible limit for drinking water except biological oxygen demand (BOD), chemical oxygen demand (COD) and , which exceeded the WHO standard in some samples. The mean abundance of the cations is , while that of the anions is . The result reveals that and are the most abundant cation and anion respectively. CF reveals a low concentration (<1) of , , , , and high concentration (>1) of . The values of PLI were very low indicating no pollution. The WQI reveals the samples with excellent (<50) rating, while those above 100 (>100) were rated as poor. The SAR, MH, KR and %Na reveal the groundwater status for irrigation based on the ratings of the indices.

Determining Pollution Level for the Marine Environment Using the Pollution Load Index

Monitoring means Monitoring, Data, Indicators, Assessment, and Knowledge. Based on this context the Pollution Load Index (PLI), has been applied using the data obtained from the analysis of water and algae. Algae and Posidonia oceanic were considered as good candidates among the different species selected by the United Nation Environmental Program (UNEP). The concentrations of the metals (Zn, Pb, Cd, and Cu) were measured in two marine green algae namely Ulva sp and Enteromorpha sp, that were collected from four Sites, during the winter and summer seasons. The results of the PLI calculated showed that the values for Enteromorpha species were 1.2 indicating a polluted condition, while PLI values for Ulva species were 3.3. With regard to site B (Juliana area), the PLI value for Ulva species was found to be 4.1 indicating an acceptable condition while it was a clean condition for the Enteromorpha species at the same sites. Enteromorpha species is a good accumulator of heavy metals and could be also a good candidate for monitoring the Libyan coastline. The results also show that the PLI index could be an important tool for the assessment of the marine environment.

Status of the Coastal Marine Environment in the Southern Red Sea, Yemen, as Reflected by Elements Accumulated in the Skeletons of Scleractinian (Stony) Corals.

The purpose of this study was to assess the level of anthropogenic contamination as well as to collect more data concerning the mineral composition of scleractinian corals from Southern Red Sea, Hodeidah Governorate, Yemen. The mass fractions of 31 elements were determined in the skeleton of nine coral colonies collected in the vicinity of the south-western coast of Yemen. All measurements were conducted by Instrumental Neutron Activation Analysis (INAA). The final results concerning the distribution of considered elements were comparable and, in some cases, inferior to those reported worldwide. The determined mass fractions of V, Cr, Mn, Fe, Ni, and Zn as Presumably Contaminating Elements (PCE) together with the mass fractions of the same elements previously reported in the literature regarding Red Sea Pleistocene corals permitted calculating the individual Contamination Factor (CF) and collective Pollution Load Index (PLI). In spite of high mass fraction values of Mn and Fe in only a few coral colonies, for all investigated places, the PLI values corresponding to studied areas were less than unit, suggesting the investigated areas could be considered as uncontaminated.

Impacts of Human Activities and Environmental Changes on Spatial-Seasonal Variations of Metals in Surface Sediments of Zhanjiang Bay, China

This study investigated the total concentrations and geochemical compositions of metals (Cd, Cr, Cu, Ni, Pb, Zn, Fe and Mn) in surface sediments of Zhanjiang Bay (ZJB) in spring and summer, to assess the contamination status, mobility and influencing factors of spatial-seasonal changes of these metals. The average total concentration for each studied metal in the surface sediments of ZJB was 0.173 μg/g for Cd, 58.25 μg/g for Cr, 17.11 μg/g for Cu, 16.89 μg/g for Ni, 28.70 μg/g for Pb, 67.91 μg/g for Zn, 30.18 mg/g for Fe, and 275.5 μg/g for Mn during the investigation period. Generally higher total concentrations of metals were found in the channel and coastal sediments of ZJB compared with those in the central ZJB, which may be probably resulted by the input of Suixi river, domestic sewage and industrial wastewater. The grain size compositions and TOC contents also had influences on the distributions of metals in ZJB. In the channel, total metals and reducible and bioavailable fractions of metals generally showed decreased concentrations in summer compared with those in spring, suggesting the release of metals from sediments. Organic matter degradation and Fe and Mn (hydr)oxides reduction processes may contribute much to this phenomenon. Relatively high proportions of Cd and Zn (average of 21.7% and 14.6%, respectively) were associated with the acid soluble fraction, indicating their high risk to the environment. The combined assessment results of enrichment factor, contaminated factor and the percentages of acid soluble fraction indicated that Cd and Zn in the surface sediments of ZJB were generally contaminated and they had medium to high risk to the environment. The average values of pollution load index in the channel, coastal and central ZJB were 1.28, 0.93 and 0.81, respectively, indicating the deterioration of surface sediments in the channel of ZJB. More attention should be paid on the metals in surface sediments of the channel of ZJB.

Spatial distribution and pollution assessment of heavy metals in sediments from the Brahmaputra River watershed in Bangladesh.

Spatial distribution and pollution assessment of selected heavy metals such as barium (Ba), chromium (Cr), nickel (Ni), lead (Pb), vanadium (V), arsenic (As), zinc (Zn), and copper (Cu) in sediments of the Brahmaputra River watershed in Bangladesh was investigated. The mean abundances (ppm) of heavy metals in sediment samples were in decreasing order Ba (375.60) > V (67.60) > Cr (54.10) > Zn (48.20) > Ni (22.28) > Pb (20.25) > Cu (7.59) > As (4.21). Concentrations of Pb and As in the sediments are enriched relative to the average upper continental crust composition, while Ba, V, Cr, Zn, Ni, and Cu decrease considerably. A higher concentration of Pb and Ni indicates that Brahmaputra River watershed samples receive a significant contribution from anthropogenic sources of heavy metals. Chromium displays marked positive correlation with V (r = 0.91, p = < 0.01), inferring a similar source materials input into the watershed. The geo-accumulation index (Igeo) values suggest that the sediments were uncontaminated to moderately contaminated by Ni, Zn, Pb, V, and Cr, whereas moderate to heavily contaminated by As and Cu. The contamination factor (CF) confirmed that sediments in the watershed were moderate to highly contaminated by As, Cu, and Cr. The pollution load index (PLI) values for most of the samples were over one (> 1), indicating an advanced decline in the watershed sediment quality. The overall results of a multivariate statistical analysis suggest that Ba, V, Cr, and Zn contents were all-natural sources, and Pb, Ni, As, and Cu were derived from both natural and anthropogenic sources.

Assessment of Trace Metal Content in Soils of Automobile Workshops around Bori Urban Area, Rivers State, Nigeria

This study was designed to assess the concentration of trace metals (Cr, Cd, Mn, Ni, Pb, Zn) in soils of automobile workshops around Bori Urban, Rivers State, Nigeria. Samples were collected from three auto mechanic workshops within the Bori urban area, Rivers State, Nigeria. The soil samples were prepared by standard procedures, and analyzed using the Atomic Absorption Spectrophotometer, AAS (Solaar Thermo Elemental Atomic Absorption Spectrometer-Model SE 71906). Detectable concentrations (mg/kg) of the metals, Zn, Mn, Pb, Cd, Ni and Cr were 4.05 ± 1.02, 9.64 ± 0.71, 13.39 ± 2.28, 2.46 ± 0.42, 2.86 ± 0.79 and 2.76 ± 0.99 respectively. The concentrations and contamination factors (CFs) across the three auto mechanic garages were of the order, Pb &gt; Mn &gt; Zn &gt; Cd &gt; Ni &gt; Cr and Cd &gt; Cr &gt; Ni &gt; Mn &gt; Pb &gt; Zn respectively while the pollution load index (PLI) values for the three auto mechanic garages were all greater than 1, indicating a decline in the soil quality for the three studied sites following the order station 3 &gt; station 1 &gt; station 2. The Geo accumulation index (Igeo) revealed that the soils were extremely contaminated by Cd and were all contaminated with trace metals when compared with regulatory standards such as WHO and world average values in shale. Therefore, regular monitoring of the soil in the studied sites be carried out to mitigate dangers implicit in the continued presence of the metals determined. &nbsp;

Ecological Risk Link to Trace Metals Levels in Surface Sediments from Fresco Lagoon, Côte d’Ivoire, West Africa

Sediment contamination with trace metals remains a current problem for aquatic ecosystems management worldwide. Surface sediments from Fresco Lagoon (Côte d'Ivoire) were analyzed to assess the contamination degree of the area. Concentrations of five selected trace metals (Pb, As, Mn, Zn, and Fe) and organic matter content were determined in samples collected from ten (10) stations, from June 2019 to March 2020. Trace metals concentrations were determined using an ICP-OES Instrument, while the organic matter contents were determined by the mass loss on ignition. The results revealed organic matter contents ranged from 5.28 to 28.31% and concentrations of trace metal (in mg.kg-1 dry weight) in the following ranges: 3.68 to 38.2 for Pb, 0.98 to 19.1 for As, 19.79 to 325 for Mn, 13.78 to 461.18 for Zn, and 1269.21 to 59862.37 for Fe. Organic matter showed a positive and significant correlation with Pb and Fe. To assess the metal pollution status in the studied area, four pollution indices were also calculated: Geoaccumulation Index (Igeo), Enrichment Factor (EF), Degree of Contamination (DC), and Pollution Load Index (PLI). Based on Igeo values, the sediments of Fresco Lagoon were in the range of unpolluted to moderately polluted with As, but unpolluted with Zn, Pb, Mn, Fe. The Enrichment factors of Pb, Zn, As, Mn, and Fe were: 64.22±52.32, 107.04±111.88, 227.29±203.06, 10.25±8.76, and 52.04±47.44 respectively, suggesting that the source of those metals was more likely to be anthropogenic. The falling trend of enrichment factors was as follows: As &gt; Zn &gt; Pb &gt; Fe &gt; Mn. Moreover, the PLI values (PLI&gt;1) showed higher values at the stations closed to the urban area, due to the influence of direct external sources such as agricultural runoff, and other anthropogenic inputs. The comparison of trace metals concentrations in sediments from Fresco Lagoon with the sediment quality guidelines showed that there was no toxic risk for benthic organisms regarding arsenic, lead, and zinc. In conclusion, the results obtained for the present work have revealed the need for the best management of anthropogenic activities regarding trace metals in general, and more particularly Pb and As.

Heavy metals in coral reef sediments of Kavaratti Island, India: An integrated quality assessment using GIS and pollution indicators

The present study aims to document the contamination levels and ecological risks of heavy metals in the sediments of Kavaratti lagoon, India. A total of 15 sediment samples were collected for the analysis of Al, Pb, Cd, Cu, Cr, Mn, Ni and Zn. The decreasing trend of heavy metals was observed in the lagoon sediment as Pb > Zn > Al > Mn > Ni > Cr > Cd > Cu. The Geo-accumulation index (Igeo) results indicate that Cu, Cr, Mn, Ni and Zn were uncontaminated, while Cd was strong to extremely contaminated and Al and Pb were moderately contaminated. The enrichment factors (EF) of Cd and Pb range from moderate to extremely high (EF > 1) indicating that they have anthropogenic origin on Kavaratti Island. The Contamination factor (Cf) indicated that Cd, Pb and Al belong to a high risk of contamination (Cf > 6). The pollution load index (PLI) value near one suggested that a moderate level of pollution occurs in the study area. The modified degree of contamination (mCd) shows that Al, Cd and Pb have an ultra- higher degree of contamination (mCd ≤ 32). The potential ecological risk (RI) index confirmed that Pb and Cd have considerable to the serious thread of ecological risk (RI > 600). Additionally, multivariate statistical analysis and pollution indexes showed that the Kavaratti lagoon is moderate to considerably polluted by heavy metals. Diesel-based power generation, activities related to shipping, untreated sewage, fishing and tourism activities are the main anthropogenic sources of heavy metal pollution on Kavaratti Island.

Assessment of Heavy Metals Accumulation in Soil and Native Plants in an Industrial Environment, Saudi Arabia

Industrial activities are associated with various heavy metals (HMs) being emitted into the environment, which may pose a threat to humans and animals. The rapid increase in an industrial activity in major cities in Saudi Arabia (SA) has raised concerns regarding the accumulation of HMs in the environment. The aim of this study is to assess the accumulation of HMs in soil and native plants in an industrial environment. We collected 36 surface soil samples and 12 plant species from 12 sites in an industrial city in central SA. The results showed that the HMs content in the soil followed a descending order of (Fe &gt; Ni &gt; Zn &gt; Pb &gt; Cu&gt; Cr &gt; Cd). The enrichment factor (EF) of HMs in the soil ranged from 0.20 to 7336. Up to 100%, 16.6%, and 6.2% of soil samples were extremely highly enriched with Cd, Ni, and Pb, respectively. Plant species Cyperus laevigatus accumulate Cd, Pb, and Ni. Citrullus colocynthis accumulate Cd and Pb in significantly (p &lt; 0.001) higher amounts than other studied species. The Pollution Load Index (PLI) values for the 12 sites ranged from 0.52–1.33 with S5 and S2 PLI &gt;1.0 indicating progressive deterioration of these sites. The Bioaccumulation Factor (BF) ranged from 0.04–2.76 and revealed that some plant species may be candidates for phytoextraction potential. The most promising plant species for phytoextraction and remediation were annuals or perennials such as Malva parviflora, Sisymbrium irio and Citrullus colocynthis, especially for Cr and Cu. This study suggests that these native plant species may be useful for phytoremediation in the area.

Element Contamination and Probable Ecological Concern in Surface Sediments of the Black Sea’s Iğneada Coasts

Enrichments of metals in surface sediments from Iğneada shores of the Black Sea were analysed to define the level of contamination in the region. For this purposes, Cd, Hg, Pb, Cu, Cr, Ni, Zn, Mn, Al and Fe levels in surface sediments were studied from 6 stations. Sediment samples were collected using a Van Veen grab. Elemental analyses in sediments were measured by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). The concentrations of metals varied from 0.031 to 0.091 for Cd; 0.025 to 0.064 for Hg; 3.32 to 7.88 for Pb; 5.75 to 13.42 for Cu; 25.63 to 40.07 for Cr; 14.8 to 28.2 for Ni; 18.29 to 33.21 for Zn; 268 to 377 for Mn; 10,987 to 17,101 for Al; and 11,521 to 20,700 mg·kg₋1 for Fe mg·kg₋1 dry wt. Metal levels were found to be much lower than recommended levels when compared to Sediment Quality Criteria for surface sediments. Enrichment Factors (EF), Geo-Accumulation Index (Igeo) and Pollution Load Index (PLI) were applied to the data for assessing the sediment quality. EF values were nearly between 0.33 and 2.4. Mostly EF for metals were less than 2, may be come from natural weathering processes or crustal substances, indicate no enrichment. However, some results of EF values slightly exceeding 2 indicate moderate enrichment. These rates aren’t thought to be important. Igeo values for all metals were less than 0 at all stations, suggesting that the Iğneada shores was uncontaminated by these studied metals. PLI values ranged from 0.410 in station I to 0.747 in station IV, indicating that Iğneada shores in the Black Sea were less impacted by these metals. PLI value for zone was found as 0.553665002. The Igeo and PLI values also suggest that surface sediments in Iğneada shores of the Black Sea is uncontaminated. &#x0D; HIGHLIGHTS&#x0D; &#x0D; Metal enrichments in surface sediments from the Black Sea coasts of İğneada were studied to determine the level of contamination in the area&#x0D; EF values less than or equal to 2 indicate that there is no contamination, and that the concentration is within the natural background prediction range. Only the EF values for Cr and Ni were between 2 and 5, indicating moderate enrichment&#x0D; The Igeo analyses revealed that the İğneada shores sediments were unpolluted for all studied metal levels at all stations&#x0D; All PLI values in the stations were between 0 and 1, indicating that İğneada shores were less impacted by these metals&#x0D; &#x0D; GRAPHICAL ABSTRACT

Seasonal variations in the abundance and distribution of microplastic particles in the surface waters of a Southern Indian Lake

Hazardous anthropogenic particles, such as microplastics (MPs) in the lake ecosystems, are a serious concern. In this work, we have investigated the seasonal occurrence and distribution of microplastics in the surface water samples of Lake Manipal in southwest India. The concentration of MPs was found to be higher during the monsoon season (0.423 particles/L) in comparison with the post-monsoon (0.117 particles/L) period. The higher abundance is attributed to the input of storm-water sewers connected to the lake as well as surface runoff during periods of high rainfall. The concentrations of small-sized (0.3–1 mm) microplastics were greater in both seasons. Approximately 96% of the microplastics were fibres, followed by smaller amounts of fragments, pellets, films, and foams. Polyethylene terephthalate (PET) was the principal polymer composition of the microplastics, followed by cellulose. The PET and cellulose fibres were mainly derived from the laundering of clothes in the residential colonies and hostels situated close to the lake. The storm-water sewers were the likely conduit for these PET fibres into the lake. The Pollution Load Index (PLI) data reveals that pollution due to microplastics in Lake Manipal falls within the Level I risk category. The PLI was higher during the monsoon season due to an increased flux of these particles from the nearby region. During the post-monsoon period, the PLI values decreased, suggesting that MPs in the water column may have settled and mixed with the sediments. The baseline data generated in this study is important as different types of birds, amphibians, and other microorganisms are present in the environment of Lake Manipal. We also propose certain policy measures that can be adopted by the regional population to mitigate microplastic pollution in the lake and its vicinity.

Bubalus bubalis Blood as Biological Tool to Track Impacts from Cobalt: Bioaccumulation and Health Risks Perspectives from a Water-Soil-Forage-Livestock Ecosystem.

Cobalt (Co) bioaccumulation, contamination, and toxicity in the soil environment, plant growth, and cattles' health are becoming a severe matter that can cause unembellished consequences in environmental safety and human health. The present research was conducted for the assurance of cobalt (Co) amassing in three forage plant species (Zea mays, Sorghum bicolor, Trifolium alaxandrium), from four ecological sites, and sewage water and in buffaloes blood was investigated. The analysis of variance showed significant differences for Co concentration in the soil and sewage water collected from all ecological sites. Meanwhile, summer and winter seasons and forage ecotypes significantly influenced the quantity of Co. The forage pastures also vary significantly in the concentration of Co in the above-ground parts. The highest Co level was present in Trifolium alaxandrium at ecological site-5. Cobalt taken from wastewater had a higher concentration in Trifolium alaxandrium during the winter. The samples which are collected from site-V and site-IV have the maximum concentration of Co because these areas receive highly contaminated water for irrigation. Cobalt tends to be bioaccumulated in the food chain and can cause serious problems in humans and animals. Bioaccumulation of cobalt in collected samples could be accredited to anthropogenic activities. Pollution load index values for all samples fell in the range below 1. The health risk index indicated the probability of health damage caused by the ingestion of contaminated fodder. An increase of Co concentration in soil, fodder, and blood owing to wastewater irrigation to crops was indicated as an outcome of this investigation. The results indicate that the Co toxicity in forage crops is attributed to Co bioaccumulation, transfer, and pollution load in the soil-water-cattle triangle. Efforts should be extended to avoid contamination of the food chain via Co-rich sewage water. Other nonconventional water resources should be used for forage irrigation.

Moss Biomonitoring of Atmospheric Trace Element Pollution in the Republic of Moldova.

The moss biomonitoring technique was used for the assessment of air pollution in the Republic of Moldova, in the framework of the UNECE ICP Vegetation Programme. The content of 11 chemical elements (Al, V, Cr, Fe, Ni, Zn, As, Sb, Cd, Cu, and Pb) was determined by neutron activation analysis and atomic absorption spectrometry in samples collected in spring 2020. Distribution maps were built to identify the most polluted sites. The highest concentrations of elements in mosses were determined in the north-eastern, central, and western parts of the country. The main element associations were identified using factor analysis. Three factors were determined, of which one of mixed geogenic-anthropogenic origin and two of anthropogenic origin. A comparison of the data obtained in 2020 and 2015 showed a significant decrease in the concentrations of Cr, As, Sb, Cd, Pb, and Cu in 2020. The state of the environment was assessed using Contamination Factor and Pollution Load Index values, which characterized it as unpolluted to moderately polluted. Possible air pollution sources in the Republic of Moldova are resuspension of soil particles, agricultural practices, vehicles, industry, and thermal power plants.

Distribution of heavy metals in surface soil near a coal power production unit: potential risk to ecology and human health.

Coal thermal power plants are the dominant factor in producing various hazardous elements in surrounding surface soil, resulting in a significant human health hazard. In the current study, the seasonal (pre- and post-monsoon) concentration of As, Cd, Co, Cr, Cu, Fe, Li, Mg, Mn, Ni, Pb, and Zn in surface soil around coal power production unit was analyzed using inductively coupled plasma-mass spectrometry (ICP-MS). The possible health risks throughout multiple exposure routes, i.e., ingestion, dermal, and inhalation were estimated for adult and children. Furthermore, geo-accumulation index (Igeo), enrichment factor (EF), pollution factor (CF), ecological risk index, and pollution load index (PLI) were applied to interpret the environmental pollution in the study area. The geospatial distribution pattern was computed to understand the trace and hazardous element distribution in the surface soil. As a result, the concentration of Fe (mg/kg) in pre-monsoon (15,620) and post-monsoon (27,180), Ni (mg/kg) in pre-monsoon (19.8), and post-monsoon (81.7) was found above the standard limits of soil prescribed by the WHO and FAO. Enrichment factor was observed between 0.95-6948 (pre-monsoon) and 0.53-116.09 (post-monsoon). The ecological risk index was found moderate to considerable for As and Cd metals during both seasons. In addition, the average PLI value was observed high for both seasons indicating the contamination of the study area with heavy metals. Moreover, Igeo values for Fe, Mg, and As were found relatively high. Conversely, health risks to the human population were found within the USEPA acceptable limits.

Evaluating a Sampling Regime for Estimating the Levels of Contamination and the Sources of Elements in Soils Collected from a Rapidly Industrialized Town in Guangdong Province, China.

Gaogang Town, a typical urban center within the Pearl River Delta region of China, suffers contamination of soils with metals/metalloids due to rapid development of industrial activities and agriculture. Few studies have been conducted to systematically describe the main sources, influencing factors, and ecological risks of metals/metalloids in soils in China. In this study, 312 surface soil samples were collected, and 15 elements were detected by plasma emission spectroscopy, atomic fluorescence spectroscopy, and atomic emission spectrometry. Element content features were analyzed by index of geo-accumulation (Igeo), pollution load index (PLI), potential ecological risk index(RI), positive matrix factorization model (PMF), and geostatistical analysis. The PLI value is between 0 and 1, indicating that the whole study area is lightly polluted. Combining PMF model and geostatistical analysis, soil elements in surface soils of Gaogang town were quantitatively apportioned into four sources: parent material and basic substances (23.5%), natural sources (32.2%), agricultural activities and industrial pollution (22.9%), and transportation (21.4%). The comprehensive analysis results show that polluted areas are mainly distributed on roads, rivers, and industrial and human activity areas. The main sources of ecological risks are factory pollution and human activity. Finally, we found that a quarter of the sampling density was the best sample size for this study.

Sediment contamination by trace elements and the associated ecological and health risk assessment: A case study from a large reservoir (Turkey).

Although Keban Reservoir (KR) is Turkey's the second largest man-made reservoir, limited data are available on the contents of trace elements (TEs) in sediments of the KR. The concentrations of 23 less- and commonly-monitored TEs in the sediments from 49 sites in the reservoir were measured to assess health risks, contamination levels and ecological risks of TEs. Concerning median Enrichment Factor values of TEs, chromium (Cr), strontium (Sr) and nickel (Ni) showed moderate enrichment, while other TEs showed minimal enrichment. Pollution Load Index values ranged from 0.33 to 0.63, indicating no a multi-element contamination case in the study area. Low ecological risk was found at 47 sites, while moderate ecological risk was recorded at two sites. The PEC (probable effect concentration) values were exceeded for Ni and Cr. Although wastewater from leather processing factory partly contributed to Cr enrichment at site 2, all TEs mainly originated from lithogenic sources. Median hazard quotient (HQ) values of zirconium (Zr) and lanthanum (La) for children from sediment ingestion were above the risk threshold of unity (HQ=4.81 and 1.39) and contributed 62.9% and 18.2% of the total health risk. Such high HQ values of Zr and La have never been reported in the literature. Hazard index values for children exceeded those for adults, indicating that children are more vulnerable to health risks than adults. Carcinogenic risk values of arsenic (As) were within the acceptable limits. Our findings indicated that in a multi-element sediment study, some less-monitored elements such as Zr and La may have an important role in health risk assessment even if they are found in the sediment at low concentrations. Therefore, this study can be a model for future similar studies evaluating the health risks of multi-elements in sediments.

Heavy metal contamination, pollution indices and health risk assessment of soil around an asphalt production company in Badagry, Lagos, Nigeria

In the environment, heavy metal contamination tends to be ecologically important considering its toxicity and pollution of the soil. It constitutes some levels of risks and hazards to humans and the ecosystem. This study assessed the heavy metal contamination, pollution indices and associated health risk of soil around an asphalt production company. A total of 13 soil samples were obtained around asphalt plant. The heavy metals such as cadmium (Cd), iron (Fe), lead (Pb), cobalt (Co) and zinc (Zn) were analyzed. Also determined were the contamination factor (CF), cancer risk (CR), degree of contamination (DC), ecological risk index (ERI), Geo-accumulation index (Igeo), hazard index (HI), lifetime cancer risk (LCR), Nemerow integrated pollution index (NIPI), pollution load index (PLI), pollution index (PI) and target hazard quotient (THQ), and they were used in estimating pollution and health risk. The ranges of Cd, Pb, Co, Fe and Zn in the samples were: 0.006-0.11, 0.09-0.34, 0.06-0.22, 0.09-184.41 and 0.39-3.15 mg/kg respectively. The Igeo, CF, ERI, PLI, DC, NIPI and PI values of the metals were within uncontaminated level. The metals THQ and HI values were lesser than the projected limit for both adults and children. The soils’ Co, Cd and Pb did not exceed tolerable CR and LCR value of 1.0×10-4. It could be suggested that the Asphalt production company activities is not contaminating the soil around them.

Seasonal and spatial variations of atmospheric depositions-bound elements over Tehran megacity, Iran: Pollution levels, PMF-based source apportionment and risks assessment

A total of 32 atmospheric depositions (ADs) samples were collected from eight sampling sites from April 2018 to March 2019 in the Tehran megacity. Elemental concentration, pollution characteristics, ecological and human health risks, and source apportionment of ADs in the < 63 μm fraction were investigated. Descriptive statistical analysis revealed that the average concentration of Zn, Cd, Pb, and Cu had the highest values over the upper continental crust (UCC). The influence of anthropogenic activities on the level of elements pollution was determined using the Geo-accumulation index (Igeo), Enrichment factor (EF), and Pollution index (PI). The findings revealed the highest Igeo values for Cd at the “extremely contaminated” level due to great influence from Cd emission sources, especially in spring. The extremely high EF values for Zn in 18.8% of samples could be attributed to the low distance of these sampling sites from the nearby industrial areas and adjacent road traffic density. PI values in the range of “considerable to extremely high” pollution were in the order of Zn > Cd > Pb > Cu > Ni > Cr. Eventually, The pollution load index (PLI) indicated the higher than unity of PLI values for all sampling sites reflecting considerable polluted sites across the study area. The ecological risk index (RI) indicated a considerable ecological risk, with the highest monomial risk values for Cd and Pb. The cumulative hazard index (HI) results showed that children encounter higher non-carcinogenic (NCR) risks than adults. However, the cumulative carcinogenic risk (CCR) of adults was 2.25 times higher than for children. The positive matrix factorization (PMF) model extracted four factors, including traffic-related sources (29.7%), local soils and crustal dust resuspension sources (24.8%), demolition and construction activities (23.5%), and industry-related emissions (22%). Among the identified sources, traffic-related sources showed the largest contribution to elements and ecological risks.