Enrichment Factor Of Heavy Metals Research Articles

A correlation study of road dust pollutants, tire wear particles, air quality, and traffic conditions in the Seoul (South Korea)

The interdependence of traffic dynamics and air quality on the concentrations of tire wear particles (TWP), heavy metals, and carbon black (CB) in road dust collected from 15 locations in Seoul, South Korea, was assessed. Pearson correlation, principal component analysis, and network analysis were employed to evaluate the correlations among traffic volume, vehicle speed, air quality parameters (PM10, PM2.5, NOx, and CO), and the concentrations of TWP (5934 to 16,253 mg/kg, average 9581 ± 4086 mg/kg), CB (371–22,287 mg/kg, average 4291 ± 6096 mg/kg), and heavy metals (Cr, Mn, Fe, Ni, Cu, Zn, As, Cd, and Pb) in road dust. The enrichment factors for heavy metals and the pollution index of TWP and CB were also calculated to evaluate the contribution of vehicle-derived particulate substances to road dust contamination. It was found that Cluster B, characterized by traffic-related variables such as traffic volume, vehicle speed, and heavy metals (Zn, Cd, and Pb), was significantly correlated with these pollutants, with correlation coefficients reaching up to 0.933. TWP was identified as a significant mediator in the increase of Zn, Pb, and Cd concentrations linked to traffic activities, contributing to pollution levels that were 2–16 times higher than the geochemical background. The presence of TWP and CB in road dust was identified as an indicator of contamination from traffic-related activities, highlighting the importance of Zn, Pb, and Cd as emerging pollutants that require targeted management strategies.

Characteristics of Soil Heavy Metal Pollution and Health Risks in Chenzhou City

The objective of this inquiry is to illuminate the attributes of heavy metal contamination and evaluate the potential ecological hazards inherent in the surface soil of Chenzhou City. A comprehensive analysis was conducted on 600 systematically collected soil samples within the study area, utilizing enrichment factors, geo-accumulation indices, comprehensive pollution indices, potential ecological hazard indices, and health risk assessment models to evaluate the degree of heavy metal contamination in the soil, potential ecological risks, and associated health hazards. The findings reveal that the average enrichment factor (EF) for each heavy metal is below 2, with the hierarchy from highest to lowest being Hg > Cd > Cu > Pb > Ni > Zn > Cr > As. Approximately 78.67% of soil samples exhibit no pollution to weak pollution levels based on heavy metal enrichment factors. Moreover, the comprehensive pollution index (IPIN) indicates that 95.17% of soil samples are within safe and pollution-free levels, indicating an overall environmentally secure setting. However, 2.67% of samples display heightened potential ecological risk levels, primarily concentrated in the southwestern region of the study area, influenced by nearby industrial activities. Additionally, it is noteworthy that both the non-carcinogenic and carcinogenic health hazards emanating from soil heavy metals to adult individuals lie within tolerable thresholds. Among these, arsenic (As), chromium (Cr), and lead (Pb) have been discerned as the principal non-carcinogenic agents. It is of particular significance that only a solitary soil specimen, located in the southwestern quadrant of the investigative region, manifests detectable health perils for children.

Assessment of heavy metals contamination and ecological risk of roadside agricultural soil, used for sunflower (Helianthus annuus L.) cultivation

The present study is an attempt for comprehensive assessment of the pollution intensity and corresponding ecological risk of heavy metals including Cd, Co, Cr, Cu, Fe, Ni, Pb, Zn and Sb for agricultural soil, located alongside the national road II-81 in Bulgaria, used for the sunflower (Helianthus annuus L.) cultivation, by various factors and indices calculation. In total, 18 surface soil samples (0 - 20 cm depth) were collected at distances 11 m, 36 m and 61 m from the road edge at two sunflower plants’ growth stages: vegetative (V-3) and maturity (R9). The total concentrations of heavy metals of soil samples, collected at two different sunflower growth stages were used for assessment of the potential ecological risk. Based on the results for the potential ecological risk index, pollution load index, enrichment factor, contamination factor and the degree of contamination, calculated from the average total concentrations, considerable pollution of the tested agricultural soil was observed, mainly with Sb. The values of enrichment factor show that with the exception of Fe, Cr and Ni the rest of the tested heavy metals are mostly from anthropogenic sources. There are strong, not statistically significant correlations between the enrichment factors, ecological risk index, pollution load index and contamination degree and the distance from the road edge and strong correlations between enrichment factors of heavy metals related to the road traffic emissions and the distance from the road edge. The values of the factors and indices above mentioned are lower at the growth stage R9 than at the growth stage V-3 that shows the sunflower capacity of accumulation of the tested heavy metals.

Heavy metal accumulation in a moderately polluted Ulhas estuary, Western India

The impact of industrialization and anthropogenic activities on the heavy metal accumulation in a moderately polluted Ulhas estuary, Mumbai is presented here. The estuarine pollution was evaluated based on the enrichment factor of heavy metals in four sediment cores collected between the river embayment and upstream locations. The results showed that the concentrations of Cr, Mn, Fe, Co, Ni, Cu, Zn, and Hg in the top 20 cm of the three downstream cores (Core 1, 2, 3) were very low, whereas core 4 collected in the upstream location showed moderate enrichment of all the metals. Most of the metals seem to have a common source such as effluents discharged from various anthropogenic activities. Statistical analyses showed that the metals in the first three cores have significant correlations with other metals as well as with organic carbon, clay, silt, or, sand. However, the fourth core was different, as it showed no correlation with sand, silt, clay, or organic carbon, as the only significant correlation was among metals. It can be therefore concluded that the first 3 cores collected from the coast to the mid-estuary exhibited normal distribution of metals owing to their geochemical normalization. However, S4 (core 4) located upstream showing moderate contamination of heavy metals seems to be a hotspot, as it is very close to the industrial discharge point. The continuous discharge of effluents fails to normalize the metals geochemically and instead, favours increased precipitation of metals as complexes, which may easily become bioavailable.

Enrichment Factors, Health Risk, and Source Identification of Heavy Metals in Agricultural Soils in Semi-arid Region of Hainan Island

To understand the enrichment factors and pollution levels of heavy metals in agricultural soils in the semi-arid region of Hainan island, 1818 surface soil samples were collected in Gancheng Town and analyzed for their heavy metal contents and physicochemical composition. Correlation analysis was used to determine the heavy metal enrichment factors. The geo-accumulation index (Igeo), comprehensive ecological risk index (RI), and hazard index (HI), as well as carcinogenic risk (CR), were used to assess the degree of pollution and health risk. Positive matrix factorization (PMF) was used to determine the primary sources of pollution and priority sources. The average values of heavy metal contents in the topsoil were 22.7, 0.128, 33.4, 14.5, 0.032, 9.32, 32.5, and 43.3 mg·kg-1 for As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn, respectively. With the exception of Zn, the concentrations of other heavy metals in the topsoil were higher than the soil background values of Hainan, showing different degrees of heavy metal accumulation effect. The Igeo revealed that the major pollutant element in soils was As, followed by Cd and Cu. The RI showed that the proportion of soil samples that were high-risk level or worse was 29.4% of the total number of samples, among which As was the major source of risk. The health risk assessment results indicated that As, Cr, and Ni exposure presented carcinogenic risk for children with high CR values. Based on PMF, four major sources of heavy metals were identified in the study area. Hg was derived mainly from industrial sources, and As was closely associated with agricultural activities. Ni, Cu, Cr, and Zn were related to soil parent materials. Pb and Cd were associated with agricultural activities and traffic emissions. The PMF models combined with correlation analysis were useful for estimating the source apportionment of heavy metals in soils.

Distribution characteristics and ecological risk assessment of heavy metals in sediments of Shahe reservoir

Shahe Reservoir of Northern Canal Basin was selected as the study area. Nineteen surface (0~20 cm) sediment samples and three sediment core samples were collected to analyze the spatial distribution characteristics of As, Cd, Cu, Mn, Pb and Zn in the sediments. The geo-accumulation index, potential ecological risk index and risk assessment code were used to evaluate heavy metal pollution, as well as its potential risk was analyzed according to the speciation of heavy metals. Results showed that the average enrichment factors of heavy metals compared to the background value in soil of Beijing were ranked at the order as the point source pollution area > the central area of the reservoir > the downstream area of the reservoir > the Nansha River > the upstream area of the reservoir > the Beisha River, namely, 2.57 times, 2.06 times, 1.97 times, 1.95 times, 1.87 times and 1.85 times, respectively. The sediment core samples in the central area of the reservoir and the inlet of the Beisha River showed a trend of increasing firstly and then decreasing with the change of depth. Pollution assessment results showed that sediment was moderately contaminated or moderately to strongly contaminated by As, but the other heavy metals were not polluted or lightly polluted. The potential ecological risk index of all sampling sites was less than 150, showing a low ecological risk. As Cr and Cu were mainly in the speciation of residues, with low bioavailability. Although the content of Mn and Zn were low, they showed high bioavailability. Based on correlation analysis and principal component analysis, it was speculated that the sources of various heavy metal pollution in the sediment were similar, which were possibly input from the external wastewater. The heavy metals in sediment were positively related to nutrients and organic matter, indicating that all of them were mostly from the same point polluted sources.

Heavy metal levels and sources in suspended particulate matters of the glacier watersheds in Northeast Tibetan Plateau

This study collected summer meltwater runoff samples from several glacier watersheds of the northeast Tibetan Plateau during June-July 2017, and measured the concentrations of 17 trace elements (Li, Be, Sc, V, Cr, Co, Ni, Cu, Zn, Ga, Rb, Mo, Cd, In, Sb, Cs, Ba) in meltwater suspended particulate matter (SPM), in order to reveal the elemental concentration, spatial distribution, and water quality in remote glacier watershed under regional anthropogenic activities. Results showed that, the concentration of heavy metal elements was relatively high in Yuzhufeng Glacier basin, ranging from 0.57 μg/L (In) to 1,551.6 μg/L (Ba), whereas in Qiyi Glacier basin it was the lowest, ranging from 0.02 to 85.05 μg/L; and relatively medium in other glacier watersheds, with total elemental concentration varying from 1,503.9 to 1726.2 μg/L. Moreover, enrichment factors (EFs) of SPM heavy metals showed significantly higher value in the downstream than that of upper glacier region of the watershed. Most heavy metals with low EFs mainly originated from crust dust, while others with higher EFs (e.g., Cd, Sb) probably originated from anthropogenic sources. Spatially, the EFs of heavy metals were higher in Yuzhufeng and Laohugou Glacier basins; while in other regions the EFs were relatively low, which may be caused by regional land-surface and atmospheric environmental differences surrounding the various glacier watersheds. Compared with other remote locations in global range, heavy metals level (e.g., Cu, Ni, and Zn) in this region is relatively higher. Meanwhile, we find that, though the water quality of the glacier basin in northeast Tibetan Plateau was relatively clean and pollution-free, it is still obviously affected by regional anthropogenic activities. Mining activities, transportation and natural weathering and erosion processes in the study areas have important effects on the content of heavy metal pollutants of river-water SPM in the glacier watershed. Moreover, backward air-mass trajectories demonstrated the potential atmospheric pollutants transport from the surrounding cities and suburbs, to deposit in the snowpack and glaciers, and then melted out and released into meltwater runoff. This study provides a new perspective on more complete view of heavy metals distribution in glacier watershed, and new understanding for the cryosphere water environment evaluation in the Tibetan Plateau region.

Uluköy ve Alemşah Sulama Göletleri(Çanakkale Türkiye) Sedimentlerinin Ağır Metal Kirliliği Bakımından İncelenmesi

Bu çalışmada, Çanakkale Ezine’de bulunan Uluköy ve Alemşah göletleri sedimentlerinin bazı fiziko-kimyasal özelliklerinin ve ağır metal konsantrasyonlarının belirlenmesi ve farklı ekolojik risk indislerine göre değerlendirilmesi amaçlanmıştır. Alanın belirlenmesi, örneklerin alınması ve analizlerin gerçekleştirilmesi (Nisan 2019-Nisan 2020) tarihleri arasında bir yıllık bir süreç içinde gerçekleştirilmiştir. Sediment örneklerinde tekstür, pH, elektriksel iletkenlik, kireç, organik karbon ile ağır metal konsantrasyonları belirlenmiştir. İlaveten sedimentlerdeki ağır metallerin kirlenme indisleri de (zenginleşme faktörü, jeobirikim indeksi ve kirlilik yük indeksi) saptanmıştır. Ağır metallerin zenginleşme faktörü Uluköy sulama göletinde Cu>Pb>Zn>Mn>Cr>Ni iken Alemşah sulama göletinde ise Cu>Pb>Zn>Mn>Cr=Ni sıralamasında belirlenmiştir. Uluköy sulama göletinde jeobirikim indeksi Fe için 8.55, Mn için 4.82, Cr için 3.06; Alemşah sulama göletinde ise Fe için 8.72, Mn için 5.13, Cr için 3.22 ve Zn için 3.12 olarak saptanmıştır. Hem Uluköy hem de Alemşah sulama göletleri sedimentlerinde ağır metallerce kirlenme saptanamamıştır. Kaynakların sürdürülebilir ve etkin kullanılması için bu tür izleme ve değerlendirme çalışmalarına önem verilmesi önerilmektedir.

Assessment of heavy metal pollution in soils: a case study of Nsukka metropolis

Owing to population growth and urbanization, there has been an increase in the number of auto mechanic workshops, vulcanizer’s shops and engine oil retail shops along the roads within Nsukka with a direct increase in heavy metal concentration in dust. Emissions from these activities pose serious environmental concern along the major roads. This study is centered on the assessment of heavy metal pollution in dust and top soil along major roads within Nsukka metropolis. Soil and dust samples were collected along major roads at maximum distance of five meters from the roads edge, with control samples collected 400 m away from the nearest road. Heavy metals (Cadmium, Zinc, Iron, Lead, Chromium, Arsenic, Copper, Nickel, and Manganese) concentrations in the dust and soil were analyzed using Atomic Absorption Spectrophotometry method. The result of the analyzed heavy metal concentration showed no significant variation from the background concentration. The concentrations of Pb and Cr showed little variation, whereas As showed the greatest variation from the background value. The results of heavy metals contamination factor in soil and dust ranged from low contamination to very high contamination (CF < 1; to CF ≥ 6). High and very high contamination values were obtained for As, Cr, and Mn in both dust and soil samples. The enrichment factor of heavy metals ranged from EF ≤ 1 (background rank) to EF> 40 (extremely high enrichment). Among the analyzed heavy metals, Zn, Pb, As, and Cr showed the highest enrichments in both soil and dust samples respectively. The result of Igeo ranged from Igeo ≤ 0 (uncontaminated) to 2 < Igeo < 3 (moderately to heavily contaminated). In the dust and soil samples, Igeo for Zn, Pb, Cd, Ni, and Cu show no contamination; Igeo for As and Cr showed moderate contaminations in some locations whereas that of Mn showed moderate to heavy contamination. Results of PLI ranged from PLI < 1 (no pollution) to 3 <PLI (extremely heavy pollution).

Chemical nature and predominant sources of PM10 and PM2.5 from multiple sites on the Silk Road, Northwest China

We analyzed particulate matter (PM10 and PM2.5) from 4 urban sites (Wuwei, Zhangye, Jiuquan and Dunhuang) located on the Silk Road of Northwest China in summer and winter of 2018 for water-soluble ions, carbonaceous aerosols and heavy metals. The focus was to examine patterns in mass concentration, chemical nature and predominant sources. The average concentrations of PM10 and PM2.5 in this region were in the range of 112–152 μg/m3 and 70–81 μg/m3, respectively, and water-soluble inorganic ions (WSIIs) and mineral dust were the two main species of PM. PM10 and PM2.5 showed a relatively homogeneous spatial distribution in this area. The ratios of chemical composition and the enrichment factors of heavy metals were also analyzed. Four sources were identified by the positive matrix factorization (PMF) model. Dust and secondary inorganic aerosols were the dominant PM10 and PM2.5 contributors, respectively, accounting for 32.2% for PM10 and 34.7% for PM2.5. The contribution of dust and factory combustion emission sources to PM2.5 in this region was higher than that in the North, East and South regions of China, while that of secondary inorganic aerosol sources was relatively lower than in these other areas. The backward-trajectory model revealed that high PM pollution was related to the air masses from adjacent polluted regions in Inner Mongolia and was characterized by high PM contributions from secondary aerosols.

Characteristics of heavy metals in size-fractionated atmospheric particulate matters and associated health risk assessment based on the respiratory deposition.

The heavy metal distributions in size-fractionated atmospheric particulate matters and the associated health risks were investigated in a typical mining and smelting area in Southwest China. The Cd, Cr, Cu, Pb, and Zn concentrations were 19.28, 44.48, 100.0, 554.0, and 601.8ng/m3, respectively, in PM2.1; and 23.45, 60.99, 95.25, 559.3, and 813.7ng/m3, respectively, in PM10. Enrichment factors of heavy metals indicated that anthropogenic sources of Cd, Cu, Pb, and Zn in the size-fractionated particles. The elevated concentrations of Cd, Cu, Pb, and Zn were dominantly enriched in submicron particles (DP < 1.1μm), whereas Cr tended to be accumulated in coarse particles (2.1 < DP < 10μm). The deposition concentrations for multiple heavy metals in the head airway region, tracheobronchial region, and alveolar regions were 321.07, 21.58, and 51.96ng/h for children, and 634.49, 42.65, and 102.68ng/h for adults, respectively. The coarse particles contributed the most to the deposition concentration of HMs in head region, whereas submicron particles had relative higher proportions in the alveolar region. Heavy metals, especially Pb, caused noncarcinogenic risk to the children as the hazard index was 4.45. Moreover, total carcinogenic risks of heavy metals (Cr, Cd, and Pb) were 4.33 × 10-5 and 7.58 × 10-5 for adults and children, respectively, indicating potential carcinogenic risks. Overall, the results of this study revealed high health risks to the residents living around the mining and smelting areas, especially the children. It was therefore urgent to control the emission of heavy metals in the atmosphere.

New insights into heavy metal elements deposition in the snowpacks of mountain glaciers in the eastern Tibetan Plateau

Atmospheric heavy metals have important environmental and health threats. To investigate atmospheric deposition and contamination of heavy metal elements in the glaciers of the eastern Tibetan Plateau (ETP), we collected the surface snow (cryoconites) samples in the Lenglongling Glacier (LG), the Gannan Snowpack (GS), the Dagu Glacier (DG), the Hailuogou Glacier (HG) and Yulong Snow-mountain Glacier (YG) in summer 2017. Samples were analyzed for concentrations and enrichment factors (EFs) of Al and trace elements (Pb, Co, Cd, Ba, Mn, Ga, Sc, V, Zn, Cr, Ni, Cu, Rb, Sb, Cs, As, Mo, Li) using inductively coupled plasma-mass spectrometry (ICP-MS). Results showed that the concentrations and EFs of heavy metals (e.g. Sb, Cu, Cr, Ni, As, Mo) were generally high value in YG, GS and LG, while were relatively low value in DG and HG, implying that ETP glaciers may have been affected by atmospheric anthropogenic pollutants deposition to varying degrees. Comparing the heavy metal concentrations in the glaciers with those in the precipitation of middle/eastern China cities and also the South Asian cities, we find that the glacial heavy metal concentrations were generally low level, though the anthropogenic pollutants were still significantly enriched. Taking the spatial distribution of As and Ni concentration/EFs in the glaciers and surrounding urban precipitation as an example, we find that the heavy metal pollutants were probably transported to the glaciers through three routes from the surrounding densely populated area of Asia. The MODIS AOD and NCEP/NCAR wind vector also demonstrated that the atmospheric pollutants originated from anthropogenic emissions of urban areas of both South Asia, and northwest and east China, mainly caused by the large scale atmospheric circulation (e.g. the South Asian Monsoon, westerlies and Eastern Asian Summer Monsoon). Therefore, control of these potential pollution emission sources of the surrounding densely populated areas in Asia could be important to ETP glaciers in future perspectives.

Anthropogenic and natural impacts in the marine area of influence of the Grijalva – Usumacinta River (Southern Gulf of Mexico) during the last 45 years

The development of the Grijalva-Usumacinta river basin exerts modifications on its discharge area. A sediment core was studied to reconstruct environmental changes and trace element contamination status during the past 45 years. 210Pb-derived mass accumulation rates indicate higher sediment input to the area since 1995, related to increased precipitation and floodings in the catchment area. Sediments show finer particles from the late 1970s on, likely related to dams construction upriver and/or land use changes. Heavy metal enrichment factors (EF < 2) suggest minimum contamination. Benthic foraminifera and redox-sensitive - elements (As, Ba, Co, Cr, Cu, Ni, Pb, V and Zn) indicate the sediments before 2000 were deposited under oxygenated conditions. Afterwards, environmental conditions changed and benthic foraminifera and dinocysts assemblages changed suggesting eutrophication and lower oxygen conditions during the last 20 years. Monitoring should be continued to assess eutrophication/hypoxic/pollution trends that could become deleterious to the marine biota.

Risks related to heavy metal pollution in urban construction dust fall of fast-developing Chinese cities.

Urban construction is a major contributor to air pollution, but few studies have examined heavy metal pollution in urban areas caused by construction dust fall. We measured the concentrations of Cr, Ni, Cu, Zn, Pb, Cd, and Hg and particle size distribution in dust fall from various construction activities in seven fast-developing cities in China and conducted a health risk assessment. Mean metal concentrations in construction dust fall were on the order of Zn (246.3mg/kg)>Cr (94.2mg/kg)>Pb (56.5mg/kg)>Cu (53.6mg/kg)>Ni (22.8mg/kg)>Cd (0.68mg/kg)>Hg (0.08mg/kg). Cu and Zn were positively correlated in areas of subway and building construction, and Pb and Cd were positively correlated in areas of road construction, likely because of the materials specific to these activities. Enrichment factors for heavy metals at all sampling sites were on the order of Cd (10.4)>Zn (6.37)>Cu (4.25)>Pb (3.84)>Hg (2.41)>Cr (2.02)>Ni (1.32). The enrichment factors for all metals except Zn indicated that heavy metal pollution was highest in road construction, followed by building and subway construction. Non-carcinogenic risks to children (hazard index >1) were 1.01-1.08 in four of the seven sampling sites, indicating possible risk from deposition of construction dust fall. In contrast, the hazard index for adults was <1at the seven cities and total carcinogenic risks (<1×10-6) were at acceptable levels. An integrated ecological risk assessment demonstrated that heavy metal particles in construction dust fall in two of the cities (Shijiazhuang and Qingdao) were likely to be suspended in the atmosphere. Our study of heavy metal pollution in construction dust fall provides data on ecological and human health impacts and suggests that extensive measures are required to control construction dust fall in China.

Assessment of heavy metal pollution in marine sediments receiving produced water, Delta State, Nigeria

Every aspect of oil and gas operations poses significant negative impacts on the environment in varying levels, these environmental impacts have economic and public health consequences on the indigenes of the operation locality. Produced water discharge is one of such aspects of the upstream oil and gas operation whose potential for environmental degradation has necessitated both local and international regulations for its governance. This research focuses on the environmental assessment of heavy metal pollution on marine sediments receiving treated produced water in Delta state, Nigeria. Sediment samples were obtained from produced water discharge area at various distances from the disposal point. Heavy metals (Cadmium, Zinc, Iron, Lead, Chromium, Vanadium, Barium, Nickel and Manganese) concentrations in the sediment were analyzed using Atomic Absorption Spectrophotometry method. In the sediment, manganese, nickel, chromium, lead, cadmium and zinc were detected in all the locations and showed no significant difference across the various locations. Barium and vanadium were detected in some location although no statistical difference was established across the locations. Iron concentration showed significant difference across the various locations. The results of heavy metals contamination factor in marine sediments ranged from low contamination to very high contamination (CF<1; 3 ≤ CF ≥ 6). High contamination values were recorded for vanadium (Location SD16, 21 and 22) and barium locations (SD8 and 21). The enrichment factor of heavy metals ranged from minimal to moderate, significant and very high enrichment. Barium, Nickel and Manganese showed the highest variation in enrichment factor. Other than cadmium and barium that showed moderate risk (40 ≤ Er <80) and very high risk (Er ≥ 320) at some locations respectively, the Ecological Risk Index of heavy metals based on the criteria for risk assessment showed low risk (Er<40) for most of the locations. Key words: Assessment, environmental impact, produced water, pollution, heavy metal, contamination, sediments.

Distribution of heavy metals in roadside dust of Petaling Jaya, Malaysia with multivariate and correlation analyses for source identification

ABSTRACT Anthropogenic emission is on the increase in urban cities due to increased human activities. However, the pollution level of heavy metals in urban environments due to emission from various anthropogenic sources could attain toxic levels to humans and biota. The roadside dust collected from Petaling Jaya, Malaysia was analysed for Pb, Cr, Cu, Cd, As, Ni, and Fe by using ZEE nit 650 P Graphite furnace atomic absorption spectroscopy. The contamination levels of these metals were assessed in terms of the geoaccumulation index (Igeo), enrichment factor (EF), contamination factor (Cf), and integrated pollution index (IPI). The result of the principal component analysis (PCA) and hierarchical cluster analysis (HCA) revealed that the variations found in different concentrations of heavy metals were mainly due to industrial and traffic emissions. The computed results of Igeo and EF of heavy metals in urban dust suggested that there were pollutions of Cd, Cu, Pb, and As. Meanwhile, Igeo and EF of Ni, Cr, and Fe were very low and posed no serious pollution. The Cf and IPI assessments also indicated that Cd, Cu, and Pb were the major pollutants in Petaling Jaya urban dust. On the other hand, the potential ecological risks for single element (Er) confirmed the IPI results and the potential ecological risk index (RI) indicated that generally, the degree of pollution of heavy metals in roadside dust of PJ was considerable. These results could help in the development of suitable management strategies to minimise pollution by using various remediation methods in Petaling Jaya.

Spatio-Temporal Dynamics of Soil Geochemical Anomalies in the Zone of Impact of Slag Residuals

The 13-year-old (from 2003 to 2016) dynamics of soil contamination for the content of heavy metals in the area of the village of Bolshoye Dumchino of the Mtsensk District in the territory adjacent to the slag dump of Mtsensk Foundry was studied. It is shown that on the territory of the placement of slag residuals a techno geochemical anomaly is formed, in which the contained heavy metals are of technogenic and genetic (natural geochemical) nature. To identify the effect of anthropogenic factor on soil pollution with heavy metals, was determined the refined enrichment factor of heavy metals (EFHM) in light gray forest soils at different distances from the slag dump, allowing to calculate the proportion of technogeneity of metals as a percentage of its total content. The technogenic origin of heavy metals as pollutants and the role of humus soil horizons in fixing these metals in the soil profile have been proven. Analysis of the results characterizing the degree of enrichment of the genetic horizons of light gray forest soils with heavy metals for the period 2003–2016 convincingly proves the effect of maximum accumulation of slag residuals in the dump on the accumulation intensity and fixation of the studied metals, both in the upper humus layer and their distribution in the profile soil. The established patterns in changing the degree of enrichment and technogenicity of heavy metals in the profile of light-gray forest soil are caused not only by the impact of the slag dump as a source of pollution, but also by the peculiarities of using the soils of the studied territories. It is shown that the toxic load for the analyzed period not only did not decrease, but even increased.

Assessment of Pb, Cd, and Zn in Isfahan’s air dust during 2015-2017 (A case study: North, West, and East Stations of Isfahan)

The present study aimed to measure the heavy metals existing in Isfahan’s dust at three stations during 2015-2017. This study was carried out in three stations located at north and northwest, west and southwest, and east and southeast parts of Isfahan. In each station, 12 sediment traps were placed and the concentrations of lead (Pb), cadmium (Cd) and zinc (Zn) in these sediment traps were determined using atomic absorption spectroscopy (AAS). The highest and the lowest concentrations of Pb in air dust were observed to be 490.1 and 70 mg/kg in western and eastern stations of Isfahan province, respectively. The highest and the lowest concentrations of Zn were 860.4 and 150 mg/kg in 2015, respectively. The highest Cd concentration (8.1 mg/kg) in air dust was found in the northern part of Isfahan province, while the lowest concentration of this metal (0.7 mg/kg) was observed in the eastern region of Isfahan. Similar results were obtained for the heavy metals enrichment factor with a maximum and minimum of 3.8 and 0.8 in 2015, respectively. The results of this study confirmed that the effect of human activities is significant in increasing the concentration of heavy metals such as Pb, Cd and Zn in dust. The assessment results for the enrichment factor of heavy metals revealed the contamination of dust by heavy metals. Accordingly, further attention is required to identify and control the pollutants sources such as heavy metals in dust in order to prevent the resulting pollution.

Heavy Metal Enrichment Factors in Fluvial Sediments of an Amazonian Basin Impacted by Gold Mining.

Artisanal and small-scale gold mining (ASGM) has been performed in the southern Ecuadorian Amazon since the colonial period. However, its effects on fluvial systems have been poorly investigated. Thus, in order to calculate the normalized enrichment factors (NEF) of several heavy metals in fluvial sediments of the Zamora River basin (Ecuadorian Amazon), we analyzed bottom sediments along ASGM-affected and unaffected river sections. The results indicated that sediments of the Congüime River have NEF between 2.2 and 2.3 for Cu (moderate contamination) and higher than 3 for Mn, Zn, Pb, and Hg (severe contamination). Similarly, a severe contamination is also observed in the lower Nangaritza River, due to sediments of this sector have NEF > 3 for Zn, Pb, and Hg. Bottom sediments from the Nambija and Zamora rivers showed a severe contamination with Hg (NEF > 3), suggesting the existence of ASGM activities in the upper Zamora River basin.

Heavy metal contents in the most productive Argentinean Humid Pampa soils

Argentinean Humid Pampa topsoil samples from sites with different land use patterns were analysed. Texture was dominated by fines (silt+clay > 50%) with high total organic carbon content (2.8 ± 1.8%), particularly in finer soils (3.7-9.9% to 0.99% in sandy soils). Carbon:nitrogen relationship was relatively homogeneous (13.9 ± 3.6%) pointing to a dominant contribution of terrestrial plant detritus. Heavy metal concentrations were low (Fe: 1.77 ± 0.50%; Mn: 446 ± 171; Zn: 48.4 ± 19.5; Cu: 17.6 ± 6.0; Pb: 10.0 ± 4.8; Cr: 7.2 ± 1.8; Ni: 6.1 ± 1.7; Cd: 0.05 ± 0.03 µg g-1) and spatially homogeneous ( 0.05). Heavy metal enrichment factors were low (0.07-2.28) indicating a natural origin.