Modified Degree Of Contamination Research Articles

Health risk assessment in sediment cores: A preliminary study in Erdek and Bandırma Bays, Türkiye

The contents of heavy metals in the core sediments of Erdek and Bandırma Bays were investigated to determine the pollution level, metal distribution and the associated human risks. It is very important to assess the concentration level of metal pollutants and health risk to adults and children. Therefore, metal analysis, contamination degree (Cdeg), modified contamination degree (mCdeg), toxic unit (TU), toxic risk index (TRI), modified hazard quotient (mHQ), and human risk assessment were carried out. The measured metals in the sediments were in the range of Al: 0.71-6.5%, Fe: 0.73-6.7%, Mn:100-923mg/kg, As: 0.5-28mg/kg, Co: 0.1-21mg/kg, Cr: 31-595mg/kg, Cu: 0.1-58mg/kg, Ni: 11-196mg/kg, Pb: 3-72mg/kg, V: 19-159mg/kg, Zn: 6-255mg/kg, Hg: 0.03-1mg/kg. Based on the Igeo, the mean values were < 0, except for Hg in cores MD72 (0.1), BD1 (0.9), and ER1 (0.2), which means that both bays are “unpolluted to moderately contaminated” with Hg. The mean mCdeg values of Erdek and Bandırma Bays sediments were very low contaminated with selected metals. The mean values of ΣTUs values for the cores (BK1, MD72, BD1 and ER1) ranged from 2.8-1.0, 4.9-0.5, 5.8-0.5, and 2.9-0.7, respectively. The mHQ-Hg and -Ni values indicated moderate to considerable significant contamination to living organisms, while it was for -Zn, -Cu, and –Pb indicated low to very low contamination to living organisms. There was no toxic risk to the marine ecosystem according to the TRI value (<5). Based on the human risk assessment using to the Hazard Quotient (HQ) that recommended by the US EPA, there are no adverse health effects by ingestion and dermal contact. Moreover, there are no non-carcinogenic and carcinogenic harm to adults and children. The results of this study will serve as a preliminary baseline human health risk assessment for Bandırma and Erdek Bays.

Heavy metals in surface sediments of Lake Patria wetland, southern Italy, and environmental risk

The study investigated the presence of heavy metals in the surface sediments of one of the most important wetlands in south Italy, Lake Patria, and the related environmental risk. Surface sediments were analyzed for particle size and shape, total organic carbon and As, Cd, Cr, Cu, Fe, Hg, Ni, Pb and Zn levels. Mean total organic carbon was high, 3.1 %, with a peak of 5.9 % near the input of freshwater channel whereas sediments appeared to be mainly composed of sand and/or gravel and significantly polluted by metals especially Cr, Cu and Zn. Data from heavy metals spatial distribution, Pearson correlation, principal component analysis and geochemical indices suggested dominant anthropogenic source for most metals. Mean Igeo values of Cr, Cu and Ni were in the range of 4.6–7.3 of strongly polluted class while their relative mean enrichment factors were largely exceeding the threshold of the anthropic pollution, 1.5. A very high pollution situation was also outlined when considering the Cf indices, with Cr, Cu and Ni possessing mean values from an order of magnitude of ten to hundred times higher the very high polluted class, 6 ≤ Cf. On the overall, the integrated indices of modified contamination degree, pollution load and ecological risk revealed a serious pollution scenario. The mean comprehensive ecological hazard index was fivefold the most critical limit, ≥600, in almost all the lagoon and especially in the locations close to channel.

Geospatial evaluation and bio-remediation of heavy metal-contaminated soils in arid zones

Introduction: Soil pollution directly impacts food quality and the lives of both humans and animals. The concentration of heavy metals in Egypt’s drain-side soils is rising, which is detrimental to the quality of the soil and crops. The key to reducing the detrimental effects on the ecosystem is having accurate maps of the spatial distribution of heavy metals and the subsequent use of environmentally sustainable remediation approaches. The objective of this work is to assess soil contamination utilizing spatial mapping of heavy metals, determine contamination levels using Principal Component Analysis (PCA), and calculate both the contamination severity and the potential for bioremediation in the soils surrounding the main drain of Bahr El-Baqar. Furthermore, evaluating the capacity of microorganisms (bacteria, fungi, and “Actinomycetes) to degrade heavy elements in the soil.Methodology: 146 soil sample locations were randomly selected near the Bahr El-Baqar drain to examine the degree of soil pollution Ordinary Kriging (OK), method was used to map and analyze the spatial distribution of soil contamination by seven heavy metals (Cr, Fe, Zn, Cd, Pb, As, and Ni). Modified contamination degree (mCd) and PCA were used to assess the research area’s soil pollution levels. The process involved isolating, identifying, and classifying the microorganisms present in the soil of the study area. The study findings showed that variography suggested the Stable model effectively matched pH, SOM, and Cd values. Furthermore, the exponential model proved suitable for predicting Fe, Pb and Ni, while the spherical model was appropriate for Ni, Cr, and Zn.Results: The study revealed three levels of contamination, with an extremely high degree (EHDC) affecting approximately 97.49% of the area. The EHDC exhibited average concentrations of heavy metals: 79.23 ± 17.81 for Cr, 20,014.08 ± 4545.91 for Fe, 201.31 ± 112.97 for Zn, 1.33 ± 1.37 for Cd, 40.96 ± 26.36 for Pb, 211.47 ± 13.96 for As, and 46.15 ± 9.72 for Ni. Isolation and identification of microorganisms showed a significant influence on the breakdown of both organic and inorganic pollutants in the environment. The study demonstrated exceptionally high removal efficiency for As and Cr, with a removal efficiency reached 100%, achieved by Rhizopus oryzae, Pseudomonas aeruginosa, and Bacillus thuringiensis.Conclusion: This study has designated management zones for soil contamination by mapping soil pollutants, geo-identified them, and found potential microorganisms that could significantly reduce soil pollution levels.

Integrated application of multiple indicators and geographic information system-based approaches for comprehensive assessment of environmental impacts of toxic metals-contaminated agricultural soils and vegetables

Conventional monitoring and mapping approaches are laborious, expensive, and time-consuming because they need a large number of data and consequently extensive sampling and experimental operations. Therefore, due to the growing concern about the potential of contamination of soils and agricultural products with heavy metals (HMs), a field experiment was conducted on 77 farm lands in an area of 2300 ha in the southeast of Shiraz (Iran) to investigate the source of metal contamination in the soils and vegetables and to model spatial distribution of HMs (iron, Fe; manganese, Mn; copper, Cu; zinc, Zn; cadmium, Cd; nickel, Ni, and lead, Pb) over the region using geographic information system (GIS) and geostatistical (Ordinary Kriging, OK) approaches and compare the results with deterministic approaches (Inverse Distance Weighting, IDW with different weighting power). Furthermore, some ecological and health risks indices including Pollution index (PI), Nemerow integrated pollution index (NIPI), pollution load index (PLI), degree of contamination (Cdeg), modified contamination degree (mCd), PIaverage and PIvector for soil quality, multi-element contamination (MEC), the probability of toxicity (MERMQ), the potential ecological index (RI), total hazard index (THI) and total carcinogenic risk index (TCR) based on ingestion, inhalation, and dermal exposure pathways for adults and children respectively for analyzing the noncarcinogenic and carcinogenic risks were calculated. Experimental semivariogram of the mentioned HMs were calculated and theoretical models (i.e., exponential, spherical, Gaussian, and linear models) were fitted in order to model their spatial structures and to investigate the most representative models. Moreover, principal component analysis (PCA) and cluster analysis (CA) were used to identify sources of HMs in the soils. Results showed that IDW method was more efficient than the OK approach to estimate the properties and HMs contents in the soils and plants. The estimated daily intake of metals (DIM) values of Pb and Ni exceeded their safe limits. In addition, Cd was the main element responsible for ecological risk. The PIave and PIvector indices showed that soil quality in the study area is not suitable. According to mCd values, the soils classified as ultra-high contaminated for Cu and Cd, extremely high for Zn and Pb, very high, high, and very low degree of contamination for Ni, Mn, and Fe, respectively. 36, 60, and 4 % of the sampling sites had high, medium, and low risk levels with 49, 21, and 9 % probability of toxicity, respectively. The maximum health risk index (HRI) value of 20.42 with extremely high risk for children was obtained for Ni and the HI for adults and children were 0.22 and 1.55, respectively. The THI values of Pb and Cd were the highest compared to the other HMs studied, revealing a possible non-cancer risk in children associated with exposure to these metals. The routes of exposure with the greatest influence on the THI and TCR indices were in the order of ingestion > inhalation > dermal. Therefore, ingestion, as the main route of exposure, is the route of greatest contribution to health risks. PCA analysis revealed that Fe, Mn, Cu, and Ni may originate from natural sources, while Fe was appeared to be controlled by fertilizer, and Cu primarily coming from pesticide, while Cd and Pb were mainly associated with the anthropogenic contamination, atmospheric depositions, and terrific in the urban soils. While, Zn mainly originated from fertilization. Findings are vital for developing remediation approaches for controlling the contaminants distribution as well as for monitoring and mapping the quality and health of soil resources.

Environmental Impact of Heavy Metals in Soils from Electronic Waste Dumpsite in Southwest Nigeria

The massive influx of electronics into Nigeria has led to environmental challenges due to increase in the production of electronic waste, which causes serious health and pollution problems. This study investigated the level and impact of heavy metals in 30 soil samples from an electronic waste disposal site in southwest Nigeria, using appropriate standard methods. The range concentrations of the heavy metals were 1615 mg/kg Pb, 20 mg/kg Cr, 266.32 mg/kg Ni, 22.39 mg/kg Cd and 242.03 mg/kg Cu at depth 0-15cm while 1453.56 mg/kg Pb, 26.31 mg/kg Cr, 497.11 mg/kg Ni, 17.04 mg/kg Cd and 230.31 mg/kg Cu were observed at depth 15-30 cm. The concentrations of the heavy metals exceeded the allowable limits, except for Cr. The mean degree of contaminations, 18.15 and 14.35, were observed at depths 0-15 and 15-30 cm respectively and indicated considerable and moderate degree of contamination by the heavy metals, respectively. The mean Potential index of 323.52 and 225.79 at depth 0-15 cm and 15-30 cm showed sever toxicity and moderate toxicity, respectively. The I-geo. of Pb at both depths indicated extreme contamination. This study reveals sever potential environmental and health hazards in the neighborhood, ecosystem, and community, and advises that the government should establish a national policy on e-waste and regulate testing of all electronics imported under the names of reuse, donation and recycling, which will halt the importation of e-scraps (e-waste).

A Comparative Study on Speciation and Availability Risk of Toxic and Potentially Toxic Elements in Different Groups of Sediments in the Dar-E-Allo Copper Mine, SE Iran

ABSTRACT The present study has been performed to evaluate the prospective effects of toxic and potentially toxic elements (TPTEs) on different groups of sediments in mining area. Fractionation of metal and metalloid elements (As, Cd, Co, Cu, Fe, Mo and Zn) was studied using a modified Community Bureau of Reference (mBCR) sequential extraction procedure in the sediments collected at five sedimentary systems. Compared to natural background values the enrichment factor (EF) of TPTEs follow the order of Cu > Mo > Cd > Zn > Co > As > Fe. Comparison with sediments quality indicators (including: sediment pollution index (SPI), pollution load index (PLI), and modified contamination degree (mCd)) revealed, that leached sediment containing secondary phases (S5 and S6), sediments containing ferric compounds (S7 and S8) and then evaporitic deposits (S9) are considered as the most contaminated sediment with a high to ultra-high degree of contamination, Subsequently based on the average indices values for sedimentary systems, the descending order is as follows: S5> S4 > S2 > S3 > S1. This issue confirm that sedimentary systems of mining area are heavily contaminated by toxic and potentially toxic elements and were not found within the guideline acceptable values. The potential ecological risk index (PERI) revealed a very high risk level for Cu with a peak in sediments containing sulfide phases. Speciation results in the investigated sediments indicated that the labile form has a considerable role in the release of all TPTEs except for Mo, Fe, and to somewhat As. Accordingly, based on the risk of elements bioavailability, the descending order is as follows: S9 > S4 > S5 > S6 > S7 > S3 > S8 > S2 > S1. X-ray diffraction (XRD) analysis confirmed the presence of lithogenic minerals with low bioavailable elements in the samples (S1, S2, S3, S4, S7 and S8) and secondary minerals with high bioavailable elements in samples (S5, S6 and S9). Multivariate statistical analysis (Pearson’s correlation analysis, PCA, and CA) suggested that the sources of TPTEs contamination were mainly anthropogenic along with the geogenic sources in the study area.

Ecological risk assessment of potentially toxic elements (PTEs) in agricultural soil, vegetables and fruits with respect to distance gradient in proximity to lead-acid battery industry

Lead-acid battery industries in Bangladesh have proliferated in urban areas, leading to the release of significant amounts of potentially toxic elements (PTEs) and metalloids into the environment. This study aimed to assess the spatial distribution, sources, contamination status, and ecological risks in agricultural soils, vegetables, and fruits near these industries. Soil samples were collected from four sites at varying distances (0 m, 100 m, 250 m, and 500 m) around three lead-acid battery industries (AA, AB, and AC) in Dhaka and Gazipur Districts during June-July 2020. The concentrations of the Pb, As, Cd and Zn in agricultural soils were ranged between 8.40–116.61, 8.99–28.21, 0.03–1.28, and 25.38–68.72 mg/kg, respectively. The concentrations of Pb, As, and Cd were found to be considerably higher than background levels across all industries, with a gradual decrease in PTE concentrations from 0 m to 500 m. The contamination factor indicated high to moderate contamination in agricultural soils by As, Cd, and Pb, and low contamination by Zn. pollution load index, modified contamination degree, and nemerow comprehensive index revealed varying pollution levels in the vicinity of the industries, with AA and AB showing higher pollution compared to AC. The individual risk factors demonstrated significant risks associated with Cd and As exposure, while Pb and Zn posed lower risks. The potential ecological risk index indicated considerable ecological risk for AA (risk index = 192.41), moderate risk for AB (risk index = 111.80), AC (risk index = 65.08), respectively. Correlation and principal component analysis revealed strong positive associations (p < 0.01) among the chemical parameters and potentially toxic elements in soils, and demonstrated the lead-acid battery industry as the primary contamination source in the studied areas. There were strong positive relationships (p < 0.01) existed between As, Cd, and Zn in soils and vegetables; while a strong negative association found between As in soils with As in Fruits. The cluster analysis showed EC, OC, OM, Pb, As and Zn into separate group, implied their same source of origin as anthropogenic source. The metal uptake was in the decreasing order of Cd > Zn > As > Pb and Cd > Zn > Pb > As in vegetable and fruit samples, respectively and transfer factor analysis highlighted Cd and Zn as metals with higher absorption rates in vegetables and fruits. Among the industries, AA and AB were significantly impacted on soil quality, and considerable metal accumulation found on vegetables. The human health risk assessment results indicate a potential noncarcinogenic health hazard for the populations surrounding the industries (AA, AB, and AC). This is evidenced by the calculation of the total target hazard quotient and the hazard index, both of which exceeded the acceptable level (>1). However, the carcinogenic health risks arising from the consumption of potentially toxic elements are within threshold values. This study provides crucial insights into the environmental as well as health impact of lead-acid battery industries, emphasizing the urgency of implementing effective environmental management practices to mitigate their consequences.

Contamination and ecological risk assessment of Cr, As, Cd and Pb in water and sediment of the southeastern Bay of Bengal coast in a developing country

Safe levels of heavy metals in the surface water and sediment of the eastern Bay of Bengal coast have not been universally established. Current study characterized heavy metals such as arsenic (As), chromium (Cr), cadmium (Cd) and lead (Pb) in surface water and sediments of the most important fishing resource at the eastern Bay of Bengal coast, Bangladesh. Both water and sediment samples were analyzed using inductively coupled plasma mass spectrometer. Considering both of the seasons, the mean concentrations of Cr, As, Cd, and Pb in water samples were 33.25, 8.14, 0.48, and 21.14 μg/L, respectively and in sediment were 30.47, 4.48, 0.20, and 19.98 mg/kg, respectively. Heavy metals concentration in water samples surpassed the acceptable limits of usable water quality, indicating that water from this water resource is not safe for drinking, cooking, bathing, and any other uses. Enrichment factors also directed minor enrichment of heavy metals in sediment of the coast. Other indexes for ecological risk assessment such as pollution load index (PLI), contamination factor (CF), geoaccumulation index (Igeo), modified contamination degree (mCd), and potential ecological risk index (PERI) also indicated that sediment of the coastal watershed was low contamination. In-depth inventorying of heavy metals in both water and sediment of the study area are required to determine ecosystem health for holistic risk assessment and management.

ASSESSMENT OF HEAVY METAL POLLUTION IN SOIL AT A REFUSE DUMPSITE IN UNIVERSITY OF CROSS RIVER STATE (UNICROSS), CALABAR, SOUTH-SOUTH, NIGERIA

Total concentration and pollution indices of mercury (Hg), lead (Pb), chromium (Cr), cadmium (Cd), arsenic (As), nickel (Ni), and cobalt (Co) in dumpsite soil located in University of Cross River State, Calabar were evaluated in this work. Soil samples were collected at 0 - 15cm depth from two sampling stations at the dumpsite once in the months of April, August and December, 2021 and analyzed to the closest mg/kg using Atomic Absorption Spectrophotometer (AAS). The concentrations of the heavy metals showed that Cd&gt;Pb&gt;Ni&gt;Cr&gt;As&gt;Co. All the concentrations of the heavy metals examined when compared with those of average value of heavy metals in shale showed that all the metals were lower than their corresponding world average value except Cd. Geoaccumulation index indicated unpolluted to moderately polluted for all metals studied except Cd which indicated strong to very strongly polluted. Contamination factor for Cd indicated very high contamination. Contamination degree for site 1 and 2 indicated considerable degree of contamination and moderate degree of contamination respectively. Pollution load index values investigated were within the baseline level for all the stations. The heavy metal pollution is attributable to the waste deposited at the dumpsite located in the institution. It is recommended that the dumpsite be relocated to another location that is far away from the residential area and from drinking water sources like boreholes.

Heavy Metals Contamination of Surface Water of Mini WHUO Stream in Port Harcourt, Rivers State, Nigeria

The level of heavy metals in the Mini Whuo Stream in Port Harcourt, Rivers State, Nigeria was assessed. The heavy metals’ analysis was performed after due digestion by the use of a Thermo Atomic Elemental Absorption Spectrophotometer. The average concentrations of the heavy metals studied in the stream were Pb; 2.594±0.76 mg/L, Cu; 1.90±0.60 mg/L, Zn; 2.50±0.74 mg/L, Cd; 0.472±0.17 mg/L, Ni; 2.785±0.87 mg/L, Cr; 4.484±0.76 mg/L, Co; 0.228±0.13 mg/L, Fe; 1.779±0.46 mg/L and As; 0.059±0.02 mg/L.The concentration of the heavy metals in the stream occurred in the order Cr &gt; Ni &gt;Pb&gt; Zn &gt; Cu &gt; Fe &gt; Cd &gt; Co &gt;&gt;As.The pollution assessment indices used in the evaluation of the anthropogenic activities has influenced the concentration of heavy metals in the stream using WHO maximum limit as basis of decision were, contamination factor, pollution load index, contamination degree and modified contamination degree. These four indices indicated that the studied heavy metals have contaminated the stream to a high level that it was no more suitable for domestic use.

A coupled geostatistical and machine learning approach to address spatial prediction of trace metals and pollution indices in sediments of the abandoned gold mining site of Bekao, Adamawa, Cameroon

Trace metals present in high amounts in aquatic systems are a perpetual concern. This study applied geostatistical and machine learning models namely Ordinary Kriging (OK), Ordinary Cokriging (OCK) and Artificial Neural Network (ANN) to assess the spatial variability of trace metals and pollution indices in surface sediments along the Lom River in an abandoned gold mining site at Bekao (Adamawa Cameroon). For this purpose, thirty-one (31) surface sediment samples are collected in order to determine the total concentrations of As, Cr, Cu, Fe, Mn, Ni, Pb, Sn and Zn. These trace metals are used to compute pollution indices as the sediment pollution index (SPI), the Nemerow index (NI), the modified contamination degree (mCD), and the potential ecological risk assessment (RI). OK, OCK and ANN models are compared to determine the best model performance. The best models are selected based on the values of the root mean square error (RMSE), the coefficient of determination (R2), the scatter index (SI) and the BIAS. Results showed that the sequence of trace metal mean concentrations in the sediments is Fe > Mn > Cu > Ni > Sn > Cr > Zn > Pb > As. The mean concentrations of Ni, Cu, Zn and Sn are above the average shale values (ASV) and the pollution status is globally moderate to significant with a low potential ecological risk. The spatial dependency obtained with semivariogram models are moderate to weak for Mn, Fe, Ni, Pb, SPI, NI, mCD, RI As, Cr, and Sn and strong for Cu and Zn. According to cross-validation parameters, ANN model is the best method for the prediction on trace metal concentrations and pollution indices in surface sediments along the Lom River in the abandoned gold mining site of Bekao.

Assessment of Edaphic pollution indices and bioaccumulation of trace metals in Solanum lycopersicum, Spinacia oleracea and Triticum aestivum: an associated health risk evaluation

The present study investigates bioaccumulation factor (Bfc), Edaphic pollution indices and associated health risk assessment of trace metals (TMs) i.e., Cu, Fe, Zn, Mn and Co in the crops, agricultural soil (AgS), and irrigation water (IgW) collected from various peri-urban area of metropolitan city of India, Lucknow. Though the level of these TMs was within the permissible limits (PL) (FAO/WHO, 2011) in AgS and IgW however it was higher than PL in tomato, spinach and wheat cultivated in the fields. The bioaccumulation factor of Cu, Fe and Mn in edible parts of tomato, spinach and wheat was 8 to 25 times higher through the AgS and 10 to 300 times higher through the IgW in the tomato, spinach and wheat samples. The enrichment factor (Efc), contamination factor (Cfc), contamination degree (Cdg) and modified contamination degree (mCdg) values of Co, Cu, Mn, Fe and Zn ranged from low to high levels of contamination, whereas the geo-accumulation index reflected low contamination in agricultural soil. on the other hand, the metal pollution load index (Mpi) was found strongly contaminated in most of the study areas. Due to the consumption of these contaminated vegetables and cereal (VCs) by human consumers, the hazard quotient (HQ), total hazard quotient (THQ) and hazard index (HI) were found to be more than the requisite value of 1, which indicates a far-long health risk in this crowded city and its surrounding regions.

Spatial dispersion hot spots of contamination and human health risk assessments of PTEs in surface sediments of streams around porphyry copper mine, Iran.

This comprehensive research has been conducted to consider the distribution of PTEs in the surface sediments of a recently developed Dar-e-Allo copper mine in dependence on the potential ecological and human health risks. Field sampling was carried out discreetly at preselected sampling spots including the natural background, the streams around the mine, waste rock drainages, evaporative deposits, sediments containing Fe oxy-hydroxides and secondary phases. Distribution of target elements (Al, As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, S, Sb, Se, and Zn) showed high levels of crustal elements. As regards, Fe, Al, and S are identified to exist as the most copious elements in the earth's crust, so have the major portion of potentially toxic elements (PTEs) in the sediment concentrations. Evaluating environmental indices reflected that in general, Cu, S, and Mo have a higher quota of contamination in sedimentary systems. the pollution load index (PLI), modified contamination degree (mCd), Contamination factor (Cf), Sediment potential index (SPI), Geo-accumulation index (Igeo) and Contamination degree (Cd) confirm that sedimentary systems of mining area are heavily contaminated by PTEs and were not found within the guideline acceptable values. The potential ecological risk index (PERI) displayed a high or severe risk level for Cu with a peak in green-blue sediments containing secondary minerals. The results of total carcinogenic risk (TCRs) show that As has high toxicity level and carries a risk of carcinogenicity among children and adults. The TCRs for Cd, Cr, Ni, and Pb with carcinogenic potential are found only in children and they are classified as the prime concern elements that have serious dangers to children's public health. The results of contamination source presumed that the sources of PTEs contamination were principally geogenic along with the anthropogenic sources in the study area. Therefore, the present study has highlighted the implication of human health risks of PTEs in sedimentary systems of copper mining, also will grant advice for prime stakeholders, including mine managers, Environmental Protection Agency, the government and public organizations in connection to protecting the environment, aquatic biota and consumer's health.

Investigation of Pollution Level of Traces Metals Elements in Agricultural Soil of Oubritenga Province of Burkina Faso

The purpose of this study was to investigate the pollution level of trace metals As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Sb, Se and Zn in agricultural soil around the water reservoir. A total of 36 soil samples were collected both during off-season agriculture and pluvial agriculture from April to October 2022. The samples were analyzed for trace metals according to the standard methods of the US EPA 2007 with a microwave plasma atomic emission spectrometer (MP-AES), Agilent Model 4210. The pollution level was assessed using contamination factor (Cf) and modified contamination degree (mCd). During the off-season, the concentration of trace metals followed in descending order as Mn > Cr > Cu > Pb > Zn. As, Cd, Co, Hg, Ni, Sb and Se were below the detectable limits. In pluvial season, the concentration of traces of metal follows the order Mn > Cr > Zn > Cu > Ni > Pb > Hg > As. Cd, Co, Sb and Se remain below the detectable limits. The concentrations of Cr, Mn and Zn were lower in the off-season agriculture than in pluvial agriculture. For Cu and Pb, the concentrations were higher in the off-season than in pluvial agriculture. The Cf ranges from 0.24 to 11.70 depending on the considered trace metal. The Cf values of As, Ni, Pb, Zn and Mn indicated that the agricultural study soil was lowery contaminated by these trace metals. The agricultural study soil was moderately contaminated by Cr and Cu, and highly contaminated by Hg. Globally the agricultural study soil presents a moderate degree of contamination (mCd 2.25) by the eight trace metals studied. This result provides information on understanding the risks of trace metal contamination of agricultural soil. It is important to anticipate the control of soil contamination through regular monitoring of toxic metals in agricultural soils, control the quality of chemicals used in agriculture and regulate their use.

Using Contamination Indices for Assessments of Heavy Metals Status of Soils around Mercury Mine, in Kurşunlu, (Konya) Province

The objective of this study was to establish contamination level for, Pb, Zn, Cu, Ni, Cr, As, Hg, Sb, Co, and Cd in soils around the old Hg mine area central part of Turkey. 34surface samples from mine area were collected. Samples were digested and the metals were determined by ICP-OES and assess metal contamination in soils by using Enrichment factor (EF), contamination factor (Cf), Geoaccumulation index (Igeo), hazard quotient (HQ) (individual metal), contamination index (Cd), modified contamination index (mCd), pollution load index (PLI), and hazard load index (HLI) (multi metal). Enrichment factor (EF), contamination factor (Cf), Geoaccumulation index (Igeo), hazard quotient (HQ)indicate that the soil in the most of studied points were unpolluted, slightly polluted or moderate degree of pollution with respect to Pb, Cr, Cd, Zn, Cu, Co and Ni, while the soils in all studied stations were extremely contaminated with respect to Hg, Sb and As. When the obtained result to by evaluated the cumulative effect of metal pollution load index (PLI), the contamination degree (Cd) and modified Contamination Degree (mCd), and hazard load index were found to be very high high pollution, ultra-high degree pollution and medium pollution respectively indicating that the studied soils in were polluted by total of studied heavy metals.

Accumulation pattern and risk assessment of metal elements in permafrost-affected soils on the Qinghai-Tibet Plateau

Permafrost-affected soils can serve as a major reservoir of metal elements (MEs) from anthropogenic sources by atmospheric transport. Understandings of the contents, sources, and ecological risks of MEs in high-altitudinal permafrost regions are helpful to mitigate environmental and human health hazards under climate change. Thus, we investigated the concentrations of 21 MEs of topsoil (0–50 cm) and evaluated the environmental quality using the ecological risk assessment methods in permafrost regions on the central Qinghai-Tibet Plateau (QTP). The results showed that (1) Ca, Al, Fe, K, Mg, Ti, and Mn (max values in mg/kg d.w.: 7.61 × 104, 5.93 × 104, 3.12 × 104, 2.33 × 104, 1.49 × 104, 0.52 × 104, and 0.06 × 104, respectively) were abundant in all sampling sites. (2) The concentrations of most MEs in the alpine wet meadow were the highest, followed by the alpine meadow and alpine desert steppe. (3) Land cover types and soil properties (soil organic carbon, pH, and soil texture) were associated with MEs. (4) Ca, Al, Fe, K, Mg, Mn, Rb, Sr, Th, Zn, V, Ni, As, Pb, Cu, and Co likely originated from geogenic/pedogenic processes, and Ti, Cr, Cd, and Hg were enriched by both natural and anthropogenic sources. (5) The modified contamination degree indicated that sampling sites in permafrost regions of the QTP were in a low pollution state, while the geoaccumulation index and enrichment factor have revealed that 37.14 % of soils showed moderate pollution of Hg, and 84.44 % of soils had moderate to high enrichment levels for Cd. This study reveals accumulation patterns of MEs in permafrost regions and provides a scientific basis for the research on the ecological security of MEs in permafrost regions influenced by climate change.

Potential ecological risk assessment of heavy metals (trace elements) in coastal soils of southwest Iran.

Heavy metal pollution has become one of the most important threats that can endanger the health of animals, the environment, and humans. The present study was performed to investigate the potential ecological risk (PER) of heavy metals [zinc (Zn), copper (Cu), cobalt (Co), molybdenum (Mo), manganese (Mn), and selenium (Se)] in the coastal soils of southwest Iran in 2019. The samples were collected from six soil sites and three depth intervals (0–15, 15–30, and 30–45 cm) among bare and vegetated coastal soils. The soil samples to study the soil properties (soil grain size, pH, EC, and soil organic carbon) and metal contamination were taken from soil (36 samples), water (6 samples), and plants (24 samples). The soil ecological risk (ER), the pollution load index (PLI), contamination degree (Cdeg), modified contamination degree (mCdeg) for heavy metal contamination in the soil, and enrichment factor (EF index) indicate the origin of metals entering the environment, and hence these parameters were investigated. The results of this study showed that the levels of Zn, Cu, Co, Mn, Se, and Mo were in the range of low-risk contaminants in this region. According to the results of the study, the risk index (RI) for metals was in the range of 1.296–3.845, which is much lower than 150, and therefore the ecological risk potential calculated in this study was in the low-risk category for toxic elements. Based on the results, it was found that agricultural, industrial, and human activities played an effective role in the accumulation of Zn, Cu, Co, Se, and Mo in the soil. In addition, the main source of Mn metal is believed to be natural due to geological activities in the region.

Assessment of heavy metal contamination and health risk in the coastal sediments of Suez Bay, Gulf of Suez, Egypt

Urban and industrial wastewaters, and the weathering of rocks are the main anthropogenic and natural sources of heavy metals (HMs) in coastal worldwide environments. The present work examined the content, distribution, potential sources, and ecological risks of HM contamination in the coastal sediments of Suez Bay, Egypt. Six pollution and health risk indices and multivariate statistical tools were applied. The ranges of HMs (μg/g) were in order: Fe (239–983), Mn (4.70–189), Cr (1.75–19.49), Co (0.04–12.87), Zn (0.78–15.57), Ni (0.78–10.90), Cu (0.23–7.53), Pb (0.74–6.92), Cd (0.10–0.97), and Hg (0.11–0.89). The results of pollution load index (PLI) and modified contamination degree (mCdeg) indicated that the Suez Bay area seems to be free from pollution. However, some individual sites recorded high concentrations of Cd and Hg, which might be attributed to the presence of some ports, industrial activities, sewage, shipbuilding workshops and heavy traffic of commercial ships. Moreover, the assessment of the carcinogenicity risks by dermal absorption was in order Cr > Pb > Cd for adults and children. However, the study area does not suffer from any potential carcinogenic risk because the total cancer risk (LCR) was less than 1 × 10−6.

Soil quality under different agricultural land uses as evaluated by chemical, geochemical and ecological indicators in mountains with high rainfall (Darjeeling Himalayas, India)

PurposeAgricultural land use associated with intensification in plant growing affects the physicochemical parameters of soils and thus soil quality. The aim of this study was to identify the quality of soils in the Peshok catchment in the Eastern Himalayas under different types of land use (tea, horticulture, rice), under high monsoon rainfall conditions.MethodsPhysical and chemical analysis were used, e.g. bulk density, pH, TOC, major and trace element content (such as Ca, Fe, K, Mg, Mn, Na, P, Ag, As, Ba, Cd, Co, Cr, Cu, Ga, Li, Mo, Ni, Pb, Sr and Zn) based on AntonPaar Multiwave 3000 microwave system and nitrogen and sulphur content using CNS Elementar Vario MAX cube analyser. In addition, ecotoxicological analyses were performed using the Microtox test. Soil quality was assessed on the basis of chemical indicators related to the mobility of trace elements (risk assessment code, individual contamination factor and global contamination factor); geochemical indicators (geoaccumulation index, enrichment factor, contamination factor, contamination degree, modified contamination degree, pollution load index and improved Nemerow pollution index); and ecological indicators (potential ecological risk coefficient and potential ecological risk index). A statistical package of Statistica v13 was used for statistical analysis.ResultsSoils in the analysed catchment are characterised by low contents of macro- and microelements. It was shown that natural factors, such as high precipitation and steep slopes, favour strong leaching of elements from the soil, and farming systems based on natural and chemical fertilisation, terracing and irrigation are not able to balance them fully. The contents of TOC and N as well as pH were determined mainly by the land use. Results of statistical analyses and geochemical indicators revealed the predominantly natural origins of elements. The higher Ga content indicated a relationship with the local geology and the higher Cu content with the use of fertilisers. Indicators showed a low ecological risk related to the presence of trace elements, and soil ecotoxicity to A. fischeri was generally determined by the acidic pH of the tested soils. Low mobility was observed for most elements, and regardless of the land use, the residual fraction predominated.ConclusionThe study showed that use of many indicators can more fully describe soil quality in relation to land use, especially in the case of a low content of trace elements. Moreover, this approach helps to better understand the changes taking place in soil quality under different land uses in mountains with high rainfall.

Heavy metal concentration in water, soil and cultivated vegetables at the edge of Kashaf Roud River, Mashhad, Iran: ecological risk assessment and bioaccumulation factor

ABSTRACT The entrance of heavy metals through human activities causes pollution of water, soil, and plants. The aim of this study was to measure the heavy metals concentration (Hg, Pb, As, and Cd) and their ecological impacts on water, soil, and vegetables in the Kashaf Roud River basin. Hence, 72 samples of irrigation water, 72 samples of soils, and 216 samples of vegetables (dill, leek, and basil) were collected. The contamination levels were evaluated by several ecological indices including Ecological Risks index (ERI), Heavy Metal Evaluation Index (HEI), Contamination factor (Cf), Pollution Index (PI), geo-accumulation index (Igeo), Potential ecological risk index (RI), Pollution load index (PLI), and modified degree of contamination (MDC). Based on obtained results, concentrations of heavy metals in water and soil samples were in the order of Pb>As>Cd>Hg. In addition, Pb and As had the highest concentration in vegetables with the mean total concentrations of 1.60 and 0.08 mgkg−1 wet weight, respectively. According to ERI value (238), water sampling site no. 3 had higher pollution than other places and was classified in the considerable ecological risk. Among the soil samples, the Cf average values followed the declining order of Cd (7.78)>Pb (6.91)>Hg (4.26)>As (2.68), so that Pb and Cd presented high contamination levels. Moreover, all soil samples of the studied region possessed PLI>1, which confirms their contamination with heavy metals. Finally, the trends in the BAF values for heavy metals in various vegetables were in order of Hg>Cd≈Pb>As for Leek and Hg>As> Pb>Cd for Dill and Basil. Concentrations of heavy metals in soil and water samples were within the national and international standard ranges. However, the concentrations of these metals in some vegetable samples exceeded the national and international levels. The utilisation of standard quality effluent for agricultural irrigation requires control measures and good organisational performance.