Road dust trace elements contamination, sources, dispersed composition, and human health risk in Chelyabinsk, Russia

Exploring the environmental risks and seasonal variations of potentially toxic elements (PTEs) in fine road dust in resource-based cities based on Monte Carlo simulation, geo-detector and random forest model

The environmental pollution caused by mineral exploitation and energy consumption poses a serious threat to ecological security and human health, particularly in resource-based cities. To address this issue, a comprehensive investigation was conducted on potentially toxic elements (PTEs) in road dust from different seasons to assess the environmental risks and influencing factors faced by Datong City. Multivariate statistical analysis and absolute principal component score were employed for source identification and quantitative allocation. The geo-accumulation index and improved Nemerow index were utilized to evaluate the pollution levels of PTEs. Monte Carlo simulation was employed to assess the ecological-health risks associated with PTEs content and source orientation. Furthermore, geo-detector and random forest analysis were conducted to examine the key environmental variables and driving factors contributing to the spatiotemporal variation in PTEs content. In all PTEs, Cd, Hg, and Zn exhibited higher levels of content, with an average content/background value of 3.65 to 4.91, 2.53 to 3.34, and 2.15 to 2.89 times, respectively. Seasonal disparities were evident in PTEs contents, with average levels generally showing a pattern of spring (winter) > summer (autumn). PTEs in fine road dust (FRD) were primarily influenced by traffic, natural factors, coal-related industrial activities, and metallurgical activities, contributing 14.9-33.9 %, 41.4-47.5 %, 4.4-8.3 %, and 14.2-29.4 % to the total contents, respectively. The overall pollution and ecological risk of PTEs were categorized as moderate and high, respectively, with the winter season exhibiting the most severe conditions, primarily driven by Hg emissions from coal-related industries. Non-carcinogenic risk of PTEs for adults was within the safe limit, yet children still faced a probability of 4.1 %-16.4 % of unacceptable risks, particularly in summer. Carcinogenic risks were evident across all demographics, with children at the highest risk, mainly due to Cr and smelting industrial sources. Geo-detector and random forest model indicated that spatial disparities in prioritized control elements (Cr and Hg) were primarily influenced by particulate matter (PM10) and anthropogenic activities (industrial and socio-economic factors); variations in particulate matter (PM10 and PM2.5) and meteorological factors (wind speed and precipitation) were the primary controllers of seasonal disparities of Cr and Hg.

Ecological and health risk assessment of heavy metals in interior dust from college campus

Contamination of college campus dust with heavy metals and the calculation of their ecological and health risks to the students and staff did not receive much attention except in recent years. This study aims to assess the ecological and human health risks of Cd, Cr, Cu, Pb, and Zn in interior dust of College of Science/University campus. An atomic absorption spectrophotometer was utilized to estimate the samples that were collected from 46 locations of the college campus including: classrooms, offices, and laboratories. The Pb, Cu, Cr and Zn metals in the interior dust of the College of Science pose low potential ecological risk, whereas Cd generates medium potential ecological risk. The gained results showed that the student and staff of the College are exposed to low non-cancerous health risks (HI < 1) caused by Cd, Cr, Cu, Pb, and Zn in interior dust. The total lifetime carcinogenic risks (TLCR) of Cd, Cr, and Pb are within the acceptable safe limit (10-6-10-4). The low non-carcinogenic health risks of Cd, Cr, Cu, Pb, and Zn and that the carcinogenic health risks of Cd, Cr and Pb fall within acceptable safe limits, measured in the interior dust of the campus of the College of Science, does not mean neglecting the continuous assessment of those risks.

Spatial distribution, pollution level and human health risk assessment of heavy metals in urban street dust at neighbourhood scale

Urban street dust (UStD) is a vital issue for human health and is crucial for urban sustainability. This study aims to enhance the creation of safe, affordable, and resilient cities by examining environmental contamination and health risks in urban residential areas. Specifically, it investigates the concentrations and spatial distribution of chromium (Cr), cadmium (Cd), nickel (Ni), copper (Cu), lead (Pb), and zinc (Zn) in UStD in Yenimahalle, Ankara. The mean concentrations of Zn, Cr, Pb, Cd, Ni, and Cu in UStD were 97.98, 66.88, 55.22, 52.45, 38.37, and 3.81 mg/kg, respectively. The geoaccumulation pollution index (Igeo) values for these elements were: Cd (5.12), Ni (1.61), Cr (1.21), Pb (1.13), Cu (0.78), and Zn (0.24). These indices indicate that the area is moderately polluted with Cr, Pb, and Ni, uncontaminated to moderately contaminated with Cu and Zn, and extremely polluted with Cd. The hazard index (HI) values for Cr, Cd, Ni, Cu, Pb, and Zn were below the non-carcinogenic risk threshold for adults, indicating no significant risk. However, for children, the HI values for Pb, Ni, Cd, and Zn were 3.37, 1.80, 1.25, and 1.25, respectively, suggesting a higher risk. Carcinogenic risk (RI) of Cd, Ni, and Pb was significant for both children and adults, indicating that exposure through ingestion, inhalation, and dermal contact is hazardous. The findings highlight the need for strategic mitigation measures for both natural and anthropogenic activities, providing essential insights for residents, policymakers, stakeholders, and urban planners.

Seasonal toxicity of urban road dust in runoff process-studies in Poland

Urban road dust (URD) is one of the most important non-point sources of pollution in agglomerations. The aim of this study was to assess the seasonal toxic effects of URD runoff in two regions of Poland. The concentrations of elements in URD and leachate were studied. The impact of pollutants in URD runoff on water organisms was evaluated using Daphtoxkit F and Rotoxkit F (LC50). The acute toxicity tests for crustaceans and rotifers were selected as the response of these taxa reflects the impact on zooplankton, a key component of aquatic ecosystem and the basis of most food webs. The concentrations of elements were found to vary depending on the site, although URD samples collected in Katowice agglomeration (Upper Silesia) had higher values of elements (Mn, Cu, Zn, As) compared to Wrocław (Lower Silesia). The concentrations of Mn, Zn, As, Cr, and Mg in water-soluble fraction of URD were higher in summer and winter in the Upper Silesia region due to rainwater runoff resulting from traffic, industries, post-industrial waste, and the presence of old heating systems. When comparing the content of elements in the water-soluble fraction between seasons, Zn, As, Cr, and Al concentrations were slightly higher in winter. The highest mortality of Daphnia magna and Brachiouns calyciflorus was observed in URD from both agglomerations in winter. However, the mortality is likely due to the concentration of elements or/and the coexistence of an unknown compound or a synergistic effect of the studied elements. This study highlights the alarming seasonal sources of elements in URD runoff, which will directly enter the food chain and affect the entire ecosystem, and human health.

An explicit review and proposal of an integrated framework system to mitigate the baffling complexities induced by road dust-associated contaminants

Road dust-associated contaminants (RD-AC) are gradually becoming a much thornier problem, as their monotonous correlations render them carcinogenic, mutagenic, and teratogenic. While many studies have examined the harmful effects of road dust on both humans and the environment, few studies have considered the co-exposure risk and gradient outcomes given the spatial extent of RD-AC. In this spirit, this paper presents in-depth elucidation into the baffling complexities induced by both major and emerging contaminants of road dust through a panorama-to-profile up-to-date review of diverse studies unified by the goal of advancing innovative methods to mitigate these contaminants. The paper thoroughly explores the correlations between RD-AC and provides insights to understand their potential in dispersing saprotrophic microorganisms. It also explores emerging challenges and proposes a novel integrated framework system aimed at thermally inactivating viruses and other pathogenic micro-organisms commingled with RD-AC. The main findings are: (i) the co-exposure risk of both major and emerging contaminants add another layer of complexity, highlighting the need for more holistic framework strategies, given the geospatial morphology of these contaminants; (ii) road dust contaminants show great potential for extended prevalence and severity of viral particles pollution; (iii) increasing trend of environmentally persistent free radicals (EPFRs) in road dust, with studies conducted solely in China thus far; and (iv) substantial hurdle exists in acquiring data concerning acute procedural distress and long-term co-exposure risk to RD-ACs. Given the baffling complexities of RD-ACs, co-exposure risk and the need for innovative mitigation strategies, the study underscore the significance of establishing robust systems for deep road dust contaminants control and future research efforts while recognizing the interconnectivity within the contaminants associated with road dust.

Remarkable contamination characteristics, potential hazards and source apportionment of heavy metals in surface dust of kindergartens in a northern megacity of China

It is essential to understand the impact of heavy metals (HMs) present in the surface dust (SD) of kindergartens on children, who are highly sensitive to contaminated dust in cities in their growth stage. A study was conducted on 11 types of HMs present in the SD of 73 kindergartens in Beijing. This study aims to assess the pollution levels and sources of eleven HMs in Beijing's kindergartens surface dust (KSD), and estimate the potential health risks in different populations and sources. The results indicate that Cd has the highest contamination in the KSD, followed by Pb, Zn, Ni, Ba, Cr, and Cu. The sources of these pollutants are identified as industrial sources (23.7%), natural sources (22.1%), traffic sources (30.4%), and construction sources (23.9%). Cancer risk is higher in children (4.02E-06) than in adults (8.93E-06). Notably, Cr is the priority pollutant in the KSD, and industrial and construction activities are the main sources of pollution that need to be controlled. The pollution in the central and surrounding areas is primarily caused by historical legacy industrial sites, transportation, urban development, and climate conditions. This work provides guidance to manage the pollution caused by HMs in the KSD of Beijing. ENVIRONMENTAL IMPLICATION: Children within urban populations are particularly sensitive to pollutants present in SD. Prolonged exposure to contaminated SD significantly heightens the likelihood of childhood illnesses. The pollution status and potential health risks of HMs within SD from urban kindergartens are comprehensively investigated. Additionally, the contributions from four primary sources are identified and quantified. Furthermore, a pollution-source-oriented assessment is adopted to clearly distinguish the diverse impacts of different sources on health risks, and the priority pollutants and sources are determined. This work holds pivotal importance for risk management, decision-making, and environmental control concerning HMs in KSD.

Pollution characteristics, associated risks, and possible sources of heavy metals in road dust collected from different areas of a metropolis in Vietnam

Road dust samples were collected from different areas in Ho Chi Minh City (HCMC)-the largest city in Vietnam to explore pollution characteristics, ecological and human health risks, and sources of heavy metals (HMs). Results revealed the level of HMs found in the samples from residential and industrial zones of HCMC in the order of Mn > Zn > Cu > Cr > Pb > Ni > Co > As > Cd, Zn > Mn > Cu > Cr > Pb > Ni > Co > As > Cd. Due to the high enrichment of Cu, Zn in residential areas and Cu, Pb, Zn in industrial areas, the HM contamination in these areas remained moderate to severe. The findings also revealed a rising trend in the level of HMs in road dust from the east to the west of HCMC, and a heavy metal contamination hotspot in the west. In addition, industrial areas were more contaminated with HMs, posing greater associated risks than residential areas. Children living in urban areas of HCMC were found to be exposed to unacceptable health risks. Meanwhile, adults living in industrial areas face intolerable cancer risk. Among the nine HMs, Cd, Pb, and Cu posed the greatest ecological risk, while Cr and As were the main culprits behind health risks. HMs in road dust might derive from non-exhaust vehicular emissions, crustal materials, and industrial activities. The results suggested that industrial areas to the west of HCMC should focus more on reducing and controlling severe pollution of HMs.

Assessment of heavy metal contamination in street dust: concentrations, bioaccessibility, and human health risks in coal mine and thermal power plant complex

Coal mining has also been associated with adverse environmental and health impacts including cancer and respiratory disorders, with the presence of thermal power plants exacerbating the problem of heavy metal pollution. Minimal studies have been conducted on the environmental impacts, health risks, and bioaccessibility of heavy metals in coal mine areas. Consequently, samples of street dust were collected from different locations in the Singrauli mine complex and analysed. Heavy metals (Cu, Ni, Zn, Cr, Co, As, and Mo) were found to be higher than the background concentration, with the maximum concentration was found in areas close to the Thermal Power Plants, like Near Vindyachal TPP, Near Shakti Nagar TPP, and Anpara. The highest geo-accumulation index value was found for Co, Mo, Zn, and As, indicating moderate to strong pollution levels. Health risk assessment (for both adults and children) revealed that Cr and Fe posed significantly higher Hazard Quotient and Hazard Index (HI) values, indicating significant non-carcinogenic threats. Moreover, Carcinogenic Risk (CR) values for Cd, Cr, and Ni indicated a risk of carcinogenicity to the public exposed to road dust. The study also examined the bioaccessibility of the metals, which showed that the gastric phase accumulated a higher percentage of Ni (42.52%), Pb (34.79%), Co (22.22%), As (20%) and Cu (15%) than the intestinal phase. Strong positive correlation was observed between metal concentration (Cu, Pb, Cr, Fe, Zn, and Mn), HI, and CR of adult and child, while bioaccessibility of intestinal phase was positively correlated with gastric phase of metals (Cu, Ni, Co, As, and Mn).

Ascertaining priority control pollution sources and target pollutants in toxic metal risk management of a medium-sized industrial city

Re-suspended surface dust (RSD) often poses higher environmental risks due to its specific physical characteristics. To ascertain the priority pollution sources and pollutants for the risk control of toxic metals (TMs) in RSD of medium-sized industrial cities, this study took Baotou City, a representative medium-sized industrial city in North China, as an example to systematically study TMs pollution in RSD. The levels of Cr (242.6 mg kg-1), Pb (65.7 mg kg-1), Co (54.0 mg kg-1), Ba (1032.4 mg kg-1), Cu (31.8 mg kg-1), Zn (81.7 mg kg-1), and Mn (593.8 mg kg-1) in Baotou RSD exceeded their soil background values. Co and Cr exhibited significant enrichment in 94.0 % and 49.4 % of samples, respectively. The comprehensive pollution of TMs in Baotou RSD was very high, mainly caused by Co and Cr. The main sources of TMs in the study area were industrial emissions, construction, and traffic activities, accounting for 32.5, 25.9, and 41.6 % of the total TMs respectively. The overall ecological risk in the study area was low, but 21.5 % of samples exhibited moderate or higher risk. The carcinogenic risks of TMs in the RSD to local residents and their non-carcinogenic risks to children cannot be ignored. Industrial and construction sources were priority pollution sources for eco-health risks, with Cr and Co being the target TMs. The south, north and west of the study area were the priority control areas for TMs pollution. The probabilistic risk assessment method combining of Monte Carlo simulation and source analysis can effectively identify the priority pollution sources and pollutants. These findings provide scientific basis for TMs pollution control in Baotou and constitute a reference for environmental management and protection of residents' health in other similar medium-sized industrial cities.

Heavy metal contamination levels, source distribution, and risk assessment in fine sand of urban surface deposited sediments of Ekaterinburg, Russia

Urban surface deposited sediments (USDS) are unique indicators of local pollution that pose a potential threat to the living environment and human health. Ekaterinburg is a highly populated metropolitan area in Russia with rapid urbanization and industrialization activities. In Ekaterinburg's residential areas, about 35, 12, and 16 samples are represented by green zones, roads, driveways, and sidewalks, respectively. The total concentrations of heavy metals was detected using a chemical analyzer inductively coupled plasma mass spectrometry (ICP-MS). Zn, Sn, Sb, and Pb have the highest concentrations in the green zone, while V, Fe, Co, and Cu represent the utmost values on roads. Moreover, Mn and Ni are the prevailing metals in the fine sand fraction of driveways along with sidewalks. Broadly, the high pollution in the studied zones is generated by anthropogenic activities and traffic emissions. The potential ecological risk (RI) was observed in high risk (IR > 600), even though the results of all heavy metals reveal no adverse health effects from the considered noncarcinogenic metal for adults and children by different exposure pathways except the children's exposure to Co in case of the dermal contact, where the HI values of Co for children in the studied zones are higher than the proposed level (> 1). In all urban zones, the total carcinogenic risk (TLCR) values are predicted as a high potential inhalation exposure.

Potentially toxic elements in surface fine dust of residence communities in valley industrial cities

A comprehensive analysis of content, pollution characteristics, health hazard, distribution, and source of some broadly concerned potentially toxic elements (PTEs, Pb, V, Mn, Cr, Ba, Zn, Ni, and Cu) in surface fine dust with particle size <63 μm (SFD63) from residence communities in Xi'an, a representative valley industrial city, was conducted in this research to analyze the quality of environment and influencing factors of valley industrial cities in China. The average contents of Ba (794.1 mg kg-1), Cu (61.3 mg kg-1), Pb (99.9 mg kg-1), Zn (408.1 mg kg-1), Cr (110.0 mg kg-1), and Ni (33.4 mg kg-1) in SFD63 of Xi'an residence communities surpassed their background contents of local soil. The high enrichment-value regions of PTEs were chiefly located in the regions with high traffic flow, high population density, and areas around industries. Zn and Pb had moderate enrichment, and the overall pollution level of PTEs was unpolluted-to-moderate and moderate pollution. Three source categories (including natural geogenic source, industrial anthropogenic source, and mixed anthropogenic source of transportation, residential activities, and construction) were identified as the predominant sources for the PTEs pollution in SFD63, with the contribution levels of 29.9%, 32.4%, and 37.7%, respectively. The assessment of health risks according to Monte Carlo simulation revealed that the 95% of the non-cancer risk of PTEs to residents (the elderly, working people, and children) was less than the threshold of 1, while the probability of cancer risk exceeding the acceptable threshold of 1E-6 was 93.76% for children, 68.61% for the elderly, and 67.54% for working people. Industrial source was determined as priority pollution source and Cr was determined as priority pollutant, which should be concerned.

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

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

Assessment of sources, environmental, ecological, and health risks of potentially toxic elements in urban dust of Moscow megacity, Russia

Potentially toxic elements (PTEs) in urban dust of Moscow megacity and related risks have been studied. 78 samples were collected in the Moscow downtown in sites with different anthropogenic load, namely, major highways, residential area, and recreation zones. The concentrations of PTEs in urban dust were determined by ICP-MS and ICP-AES. Then, environmental, ecological and health risks of PTEs in urban dust were assessed. In addition, potential sources of PTEs in dust were identified. It is shown that Moscow dust is mainly contaminated by Sb, Zn, Pb, Cd, Cu, Sn, and Mo, which according to the data of principal component and correlation analyses can be attributed to anthropogenic sources (non-exhaust vehicle emissions). Potential ecological risk factor demonstrates that Cu, Mo, and Cd have moderate potential ecological risks in 13% of studied area, while Sb has this risk in 62% of area. Potential ecological risk indices indicate that 41% of studied territory is of moderate ecological risk. Concerning the human risks through ingestion, dermal contact, and inhalation pathways, PTEs in Moscow dust have no significant non-carcinogenic risks for adults. However, the value of total hazard index for children is 1.8 showing that non-carcinogenic risks may occur. Moreover, possible carcinogenic risks caused by Cr are evaluated. The finding of the present study can be used for ecological management in the megacity to reduce both ecological and human risks. A special attention should be given to periods of hot and dry weather and to traffic-related emissions.

Contamination levels and source apportionment of potentially toxic elements in size-fractionated road dust of Moscow

The distributions of potentially toxic elements (PTEs) among PM₁, PM_1-10, PM_10-50, and PM_50-1000 fractions of the road dust were studied in the western and eastern parts of Moscow, impacted mainly by the road transport and the industrial sector, respectively. The partitioning of PTEs in road dust can provide more precise information on pollution sources and its further interpretation regarding human health risks. The concentrations of PTEs were analyzed by mass and atomic emission inductively coupled plasma spectrometry. Differences in the results between the western and eastern parts of the city were caused by the dissimilarity between traffic and industrial emissions. The source apportionment of the PTEs was carried out using absolute principal component analysis with multiple linear regressions (PCA/APCS-MLR). The contribution from anthropogenic sources was significant to PM₁ and PM_1-10 particles. In coarser fractions (PM_10-50, PM_50-1000), it decreased due to the input with the wind-induced resuspension of soil and rock particles. In the eastern part of the city, the accumulation of PTEs (especially Mo, Sb, Cd, Sn, Bi, Co, and As) is the most active in PM_1-10, while in the western part, it is most pronounced in PM₁ (especially Pb, Cu, Cr, and W) which is associated with differences in the size of particles coming from traffic and industrial sources. In the eastern part of Moscow, in comparison with the western part, the contribution from industrial sources to the accumulation of PTEs in all particle size fractions was higher by 10-30%. In the western part of Moscow, the finest particles PM₁ and PM_1-10 demonstrate the trend of rising pollution levels with the increase in road size, while in the eastern part of the city, only coarse particles PM_50-1000 show the same trend. In the fractions PM₁ and PM_1-10 of road dust, a significant contribution was made by anthropogenic sources; however, its role decreased in the coarse fractions-PM_10-50 and especially in PM_50-1000- due to the influence of roadside soils and their parent material.

A Comprehensive Exploration on Occurrence, Distribution and Risk Assessment of Potentially Toxic Elements in the Multi-Media Environment from Zhengzhou, China

Road dust (RD), roadside soils (RS) and river surface sediments (sediments) are important materials for evaluating contaminant levels in urban areas. This study aims to investigate the contaminant characteristics, pollution levels and ecological risks of RD, RS and sediments of potentially toxic elements (PTEs), including Cr, Ni, Cu, Zn, As, Cd, Hg and Pb, in the central urban area of Zhengzhou. Results reveal that RD shows a higher concentration of PTEs when compared to the other two environments. The spatial distribution characteristics suggest that PTEs in RD, RS and sediments may come from different sources. The geo-accumulation index (I_geo) was used to describe that the RD was moderately to extremely contaminated with Cd and Hg, while both RS and sediments were significantly enriched with Cd and Hg. For RD, RS and sediments, the potential ecological risk (RI) demonstrates a high potential ecological risk from Cd and Hg. Overall, PTEs in Zhengzhou road dust present a moderate risk.

Pollution characteristics and health risks of heavy metals in road dust in Ma'anshan, China

Road dust contains various heavy metals, which are re-suspension in the air under the action of wind and other external forces, threatening people's health all the time. Road dust was collected in the industrial heavy traffic area (IHT), non-industrial heavy traffic area (HT), urban area (UA), and study recreation area (SR) of Ma'anshan. The pollution degree of heavy metals in the four areas was calculated and demonstrated IHT > HT > UA > SR. In addition to the Ni (24.24 mg kg^-1)metals, the metals concentrations of Cr (74.14 mg kg^-1), Cu (91.8 mg kg^-1), Zn (393.03 mg kg^-1), Cd (9.93 mg kg^-1), and Pb (72.85 mg kg^-1) were all higher than the local soil background values. Cu comes from traffic emissions, Pb, Cd, and Zn mainly come from industrial emissions, as well as traffic emissions. While Cr and Ni mainly come from industrial emissions and local soil re-suspension. The non-carcinogenic risk of each heavy metal to children is 10 times higher than that of adults. Among them, the non-carcinogenic risk of Cr, Cd, and Pb to children is close to 1, so great attention should be paid to it. According to the study of enrichment factor (EF) and geo-accumulation index (I_geo), Cd is extremely polluted and it is imperative to reduce Cd pollution.

Potentially harmful elements in urban surface deposited sediment of Ekaterinburg, Russia: Occurrence, source appointment and risk assessment

In this study, the human health risks of potentially harmful elements (PHEs) in urban surface deposited sediments (USDS) were examined by collecting urban dust samples, measuring their PHE concentrations, and using index evaluation. About 35, 12 and 16 samples are represented a green zones, roads, driveways and sidewalks in residential areas of Ekaterinburg, respectively. The dust fraction (0.002-0.1 mm) was obtained by sieving, filtration, and decantation process. Total concentrations of 10 PHEs were measured using inductively coupled plasma mass spectrometry. The highest concentrations of Pb were found in USDS from green zones, while Fe, V, Mn, Co, Ni, Sn, and Sb on roads, Cu and Zn on driveways and sidewalks. The contamination levels in the investigated land-use areas were studied, where the highest contamination was contributed from Sb in the driveways and sidewalk. Moreover, the pollution in the studied zones was a high load, contributing to anthropogenic activities and traffic emissions. No non-cancerogenic risk was attributed from the PHEs based on the results of health indices (HI < 1) for both adult and children, except Co and Ni which has HI > 1 for children. The total carcinogenic risk (TLCR) in all urban landscape areas is defined as a high potential inhalation exposure and a low potential ingestion and dermal exposure.

Occurrence and health implications of heavy metals in preschool children's clothing manufactured in four Asian regions

Clothing may be a potential contributor to body metal burden in children. However, available information on heavy metals in children's clothing is extremely limited and the associated health risks remain poorly understood. This study investigated the concentrations of Pb, Cd, Co, Zn, Cr, As, Cu and Ni in new preschool children's clothing manufactured in four Asian regions. The children's clothing had higher levels of Ni and Cr but lower levels of Pb and Cd in comparison to the concentrations reported in other textile products. The concentrations of Cd were higher in the black clothing than those in the white and color samples. The non-cotton samples contained higher Co concentrations. The Pb concentrations in the samples manufactured in China were significantly higher than those in the other three regions. We estimated the dermal exposure doses for these metals and calculated the associated risks. The results indicated that the health risks from exposure to these metals in the children's clothing were acceptable. However, more research is required to investigate heavy metals and the associated risks in child clothing due to the increasing complexity of their materials and manufacturing processes.

Pollution Characteristics, Source Apportionment, and Health Risk Assessment of Potentially Toxic Elements (PTEs) in Road Dust Samples in Jiayuguan, Hexi Corridor, China

The sources of potentially toxic elements (PTEs) in road dust are complex and potentially harmful to humans, especially in industrial cities. Jiayuguan is the largest steel-producing city in Northwest China, and this study was the first to conduct a related study on PTEs in road dust in this city, including the pollution characteristics, source apportionment, and health risk assessment of PTEs in road dust. The results showed that the highest concentration of PTEs in the local road dust samples were Mn, Ba, Zn, and Cr. The enrichment factor (EF) of Se was the highest, and it was "Very high enrichment" in areas other than the background area, indicating that the local Se was more affected by human activities. The geoaccumulation index (I_geo) of Se was also the highest, and the pollution level was 5 in all areas except the background area, indicating that the local Se was more polluted and related to coal combustion. The sources of PTEs in local road dust samples mainly included geogenic-industrial sources, coal combustion, traffic sources, and oil combustion. For the non-carcinogenic risk, the hazard index (HI) of each element of children was higher than that of adults, and the sum of the HI of each element was greater than 1, indicating that there was a non-carcinogenic risk under the combined influence of multiple elements, which was especially obvious in industrial areas. For the carcinogenic risk, the cancer risk (CR) of Cr at a certain point in the industrial area exceeded 10^-4, which was a carcinogenic risk, and the Cr in this area may be related to the topsoil of the local abandoned chromate plant.

Pollution Characteristics and Human Health Risk Assessment of Heavy Metals in Street Dust from a Typical Industrial Zone in Wuhan City, Central China

This study aimed to assess the pollution levels, sources, and human health risks of heavy metals in street dust from a typical industrial district in Wuhan City, Central China. In total, 47 street dust samples were collected from the major traffic arteries and streets around Wuhan Iron and Steel (Group) Company (WISC) in Qingshan District, Wuhan. The concentrations of heavy metals (Cr, Mn, Ni, Zn, Fe, Cu, and Cd) in street dust were determined by atomic absorption spectroscopy. Results indicated that the mean concentrations of Zn (249.71 mg/kg), Cu (51.15 mg/kg), and Cd (0.86 mg/kg) in street dust were higher than their corresponding soil background values in Hubei Province. Heavy metal enrichment is closely related to urban transportation and industrial production. The pollution level of heavy metals in street dust was assessed using the geo-accumulation method (I_geo) and potential ecological risk assessment (PERI). Based on the I_geo value, Cr, Mn, Fe, and Ni showed no pollution, Zn and Cu showed light to moderate contamination, and Cd showed moderate contamination. The PERI values of heavy metals in street dust ranged between 76.70 and 7027.28, which represents a medium to high potential ecological risk. Principal component analysis showed that the sources of heavy metals in street dust were mainly influenced by anthropogenic activities. Among the studied metals, Cu, Cr, Zn, Fe, and Mn mainly come from industrial processes, while Ni and Cd come from traffic exhaust. The non-carcinogenic risk indexes of heavy metals for children and adults are ranked as Cr > Cu > Ni > Cd > Zn. The health risks to children through the different exposure pathways are higher than those for adults. Hand-to-mouth intake is the riskiest exposure pathway for non-carcinogenic risk. In addition, Cr, Ni, and Cd do not pose a carcinogenic risk for the residents.

Geochemistry of street dust in Tyumen, Russia: influence of traffic load

This study investigates the elemental composition, organic carbon content, pH values, and particle size characteristics in 50 road dust samples collected from Tyumen, a large city in Western Siberia (Russia). The content of 62 major and trace elements was studied using atomic emission spectrometry (ICP-AES) и inductively coupled plasma spectrometry (ICP-MS). It was revealed that the dust has an alkaline reaction pH = 7.4-10.2 and low organic carbon content (0.07-2.9%). The grain size distribution of the road dust samples revealed that the predominant grain size fraction was of 100-250 μm. The content of small particles (PM₂ and PM₁₀) representing the greatest environmental hazard is minimal on roads with an average traffic intensity. Studies have shown that the main road dust pollutants in Tyumen are Ni, Sb, Cr, Zn, and Co. The average geoaccumulation index (Igeo) values are ranked as Ni (2.2) > Sb (1.5) > Cr (1.3) > Zn (0.4) > Co (0.4) > Cu (0.2). The contamination evaluation through enrichment factor (EF) calculation showed that road dust is highly enriched in Ni and significantly in Cr and Sb. More than 80% of Zn, Co, and Cu and more than 90% of Ni, Sb, and Cr come from anthropogenic sources. The average concentration of Ni and Cr in the road dust of Tyumen is one order of magnitude higher than in other cities of the Earth where similar studies were carried out. The high Ni content is associated with the composition of local soils and roadways, increased content in vehicle exhaust gasses, and abrasion of metal parts. Calculations of the total enrichment index Ze showed that the level of road dust pollution in most of Tyumen's territory is hazardous.

Source apportionment and health risk assessment for potentially toxic elements in size-fractionated road dust in Busan Metropolitan City, Korea

Potentially toxic elements' (PTEs; V, Cr, Co, Ni, Cu, Zn, As, Cd, Sb, Pb, and Hg) pollution level was investigated in size-fractionated road dust in Busan Metropolitan City. Health risks to humans (adult and children) were also evaluated in fine particle fraction (< 63 μm) of road dust. PTE concentrations in the fine particles (< 63 μm) were ranked as follows (unit: mg/kg): Zn (2511) > Cu (559) > Cr (531) > Pb (385) > Ni (139) > V (83.8) > Sb (31.6) > Co (21.6) > As (17.2) > Cd (4.1) > Hg (0.38). The PTE concentrations in fine particles (< 63 μm) were significantly higher than those in coarse particles except for V, Co, and As. The mean PTE loadings of fine particle fraction (< 63 μm; 233 mg/m2) in road dust were up to 4.5 times higher than other particle fractions. Igeo values of Sb were higher than 5 except for > 1000-μm fraction, indicating extremely polluted status. PCA results and elemental ratios indicated that most of the PTEs in road dust were derived from non-exhaust traffic-related sources such as brake pads and tires. Cr, Pb, and Sb had higher HI values than other metals for both adults and children. Sampling sites of heavy traffic and industrial areas showed that the carcinogenic risk exceeded the maximum threshold level (10 - 4). Especially in children, the mean carcinogenic risk (ingestion pathway) of As (6.8 × 10 - 4) Cd (2.0 × 10 - 4), and Ni (4.1 × 10 - 4) exceeded the maximum threshold level, indicating that continuous exposure to road dust may pose a high cancer risk to children. Therefore, continuous monitoring and management of these metals are needed to protect human health and the urban environment.

A four-way model (FEST) for source apportionment: Development, verification, and application

In studying the spatial, temporal, and particle size variations heavy metal sources, a source apportionment model for a four-way array of data is required. In this study, referencing two-way and three-way models, a four-way (particle fractions, elements, sites, and time) source apportionment model (FEST) was developed. Errors in the three-way models solving four-way problems verified the necessity of developing the FEST model. The results showed that the FEST model had a higher accuracy than the existing models, which was probably because of more constraints and input data in the FEST model. Based on the sampled data in Beijing, sources were apportioned for the four-way array of data using the FEST model, and the spatial, temporal, and particle size variations of sources were evaluated. The main sources of heavy metals were similar to those in our prior studies, whereas the contributions of sources to specific heavy metals differed. Traffic exhaust and fuel combustion contributed more to fine particles than coarse particles, indicating that the two should be controlled preferentially among all sources. The management of traffic exhaust should be focused on the central and northern areas in each season, and the control of fuel combustion should be strengthened in the southern area in winter.

The Content and Sources of Potentially Toxic Elements in the Road Dust of Surgut (Russia)

The chemical and particle size composition of road dust in Surgut, which is a rapidly developing city in Western Siberia, was studied for the first time. Contents of major and trace elements were determined using ICP-MS and ICP-AES, respectively. It was found that the road dust had an alkaline pH (from 7.54 to 9.38) and that the particle size composition was dominated by the 100–250-μm fraction. The contamination assessment based on calculations of the enrichment factor (EF) showed that the road dust was significantly enriched in Sb and Cu and moderately enriched in Zn, Pb, Mo, Ni and W. The sources of these elements are probably associated with the abrasion of car tires and brake pads. Based on calculations of global pollution index (PIr) and total enrichment factor (Ze), the road dust of Surgut was characterized by a generally low level of potential ecological risk, except for stretches of road subject to regular traffic jams, where a moderate ecological risk level was identified. In comparison to the other Russian cities (Moscow, Chelyabinsk, Tyumen, etc.) where studies of road dust composition have been carried out, Surgut had similar contents of Cr and Cu and relatively lower contents of Sb, Cd, As and Pb.

Potentially Toxic Element Levels in Atmospheric Particulates and Health Risk Estimation around Industrial Areas of Maros, Indonesia

Air quality deterioration is a major environmental problem in Indonesia. This study evaluated the levels and health risks of potentially toxic elements (PTEs) in Maros Regency, Indonesia. Total suspended particulate matter was collected from industrial areas for PTE (Al, Pb, Cr, Cu, Ni, As and Zn) analysis using inductively coupled plasma optical emission spectrometry (ICP-OES). Samples were collected from six critical areas in the Bantimurung region as that is where marble, cement and limestone industries are located. A calculation of the non-carcinogenic and cancer risks was performed to determine the potential health exposures in adults and children. A Monte Carlo simulation with 10,000 iterations and a sensitivity analysis was carried out to identify the risk probability and the most sensitive variable contributing to cancer risk from PTE exposure in humans. The results showed that the concentration of PTEs decreased in the order of Zn > Al > Cr > Pb > Cu > Ni > As in the wet season, and Zn > Al > Pb > As > Cr > Cu > Ni in the dry season. The hazard index (HI) value for children was 2.12, indicating a high non-carcinogenic risk for children. The total cancer risk (TCR) values in adults and children were 3.11 × 10⁻⁵ and 1.32 × 10⁻⁴, respectively, implying that both are at risk for developing cancer. The variables with the most contribution to cancer risk from As, Cr and Pb exposure in adults and children were As concentration (33.9% and 41.0%); exposure duration (ED) (34.3%) and SA (40.7%); and SA (98.7 % and 45.4%), respectively. These findings could be used as the scientific basis for public health intervention and to raise awareness of the harmful health effects of particulate bound PTEs

Elemental Composition of PM2.5 and PM10 and Health Risks Assessment in the Industrial Districts of Chelyabinsk, South Ural Region, Russia

Air pollution impacts all populations globally, indiscriminately and has site-specific variation and characteristics. Airborne particulate matter (PM) levels were monitored in a typical industrial Russian city, Chelyabinsk in three destinations, one characterized by high traffic volumes and two by industrial zone emissions. The mass concentration and trace metal content of PM_2.5 and PM₁₀ were obtained from samples collected during four distinct seasons of 2020. The mean 24-h PM₁₀ ranged between 6 and 64 μg/m³. 24-h PM_2.5 levels were reported from 5 to 56 μg/m³. About half of the 24-h PM₁₀ and most of the PM_2.5 values in Chelyabinsk were higher than the WHO recommendations. The mean PM_2.5/PM₁₀ ratio was measured at 0.85, indicative of anthropogenic input. To evaluate the Al, Fe, As, Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn concentration in PM_2.5 and PM₁₀, inductively coupled plasma mass spectrometry (ICP-MS) was used. Fe (337–732 ng/m³) was the most abundant component in PM_2.5 and PM₁₀ samples while Zn (77–206 ng/m³), Mn (10–96 ng/m³), and Pb (11–41 ng/m³) had the highest concentrations among trace elements. Total non-carcinogenic risks for children were found higher than 1, indicating possible health hazards. This study also presents that the carcinogenic risk for As, Cr, Co, Cd, Ni, and Pb were observed higher than the acceptable limit (1 × 10⁻⁶).

Pollution characteristics, spatial distribution, and source identification of heavy metals in road dust in a central eastern city in China: a comprehensive survey

Road dust enriched with heavy metals (HMs) is detrimental to ecosystems and human health in urban environments. In this study, it is to explore the concentrations, spatial distribution, contaminated levels, and source identification of six HMs (lead (Pb), zinc (Zn), copper (Cu), cobalt (Co), chromium (Cr), and nickel (Ni)) based on 130 road dusts in Xinyang urban area. The results indicated that the contents of Pb, Zn, Cu, and Co were higher than the background values in more than 99% of the samples, and their average concentrations were 15.2, 9.2, 8.6, and 6.3 times the background value, respectively. The spatial distribution of high-value areas for Pb, Zn, Cu, Cr, and Ni was more similar, which was associated with traffic density near major roads and population and settlement patterns. Co was relatively different from the five elements, which was distributed in the areas of residence, commerce, and industry. Furthermore, the investigated HMs were clearly polluted, with Pb, Zn, Cu, and Co indicating high levels of contamination, while Cr and Ni were moderately polluted. The comprehensive pollution of the six HMs was mostly moderate to heavy in this study. Moreover, three sources of HMs designated by correlation analysis (CA) and principal component analysis (PCA) were mixed traffic emissions and industrial waste for Cu and Cr; automotive emissions for Pb, Ni, and Zn; and mixed domestic waste and industrial activities for Co, with contributions of 42.3%, 46.4%, and 11.3% via the principal component analysis-multiple linear regression (PCA-MLR) model. The multi-factor index for pollution assessment combined with source identification is extremely effective and practical for providing reliable data support and a theoretical reference for pollution monitoring and governance.

Concentrations of Major and Trace Elements within the Snowpack of Tyumen, Russia

A study on the composition of snow allowed for a quantitative determination of pollutants deposited from the atmosphere. Concentrations of dissolved (<0.45 μm) and particulate fractions of 62 chemical elements were determined by ICP–MS and ICP–AES in 41 samples of snow from Tyumen (Russia). The background sites were characterized by a predominance of the dissolved phase of elements, except for Al, Sn, Cr, Co and Zr. The increased concentrations of dissolved Cd, Cu, Zn, Pb, Ni, As and Mo can be explained by a long-range atmospheric transport from the sources located in the Urals. The urban sites showed multiple increases in particulate depositions and a predominance of the particulate phase, with a high degree of enrichment in many heavy metals. Sources of trace elements were determined according to the enrichment factor (EF). Highly enriched elements (Pb, Sb, Cd, Ag, Mo, As, Zn and Cu) with an EF > 100 were emitted from anthropogenic sources. According to the potential ecological risk index (RI), the worst ecological conditions were identified in Tyumen’s historical center, industrial zone and along roads with the heaviest traffic. The data obtained in the present study allowed us to identify the most polluted parts of the city, which are located in the center and along the roads with the most intensive traffic. This research could offer a reference for the atmospheric pollution prevention and control in Tyumen.

Temporal variations of levels and sources of health risk associated with heavy metals in road dust in Beijing from May 2016 to April 2018

To analyze the temporal variations of heavy metals, health risk, and source-specific health risk, 24 road dust samples were collected from Beijing in each month in two years. The temporal variations of Hg, Pb, and Ni were higher than other heavy metals. Most heavy metals reached their highest concentrations either in winter or in spring, then the concentrations decreased and reached the lowest values in autumn. Human health risk assessment (HHRA) model showed that As, Cr, and Ni might pose cautionary carcinogenic risk (CR) to children (CR > 10^-6). CR for adults were only 0.15 to 0.19 times of that for children. Four sources were identified based on positive matrix factorization model and HHRA model, they were traffic exhaust, fuel combustion, construction, and use of pesticides and fertilizers. Influenced by the difference of carcinogenicity of heavy metals, traffic exhaust contributed the largest to heavy metals (36.02%, over 42.24% higher than other sources), while contributions of fuel combustion to CR (36.95%) was similar to traffic exhaust (37.17%). Monte-Carlo simulation showed that the 95th percentile of probability density functions of CR posed by Cr and Ni from each source were 9.90 × 10^-5 to 2.64 × 10^-4, posing cautionary carcinogenic risk to children. The seasonal change of CR varied among different sources. CR from use of pesticides and fertilizers in spring was 35.06 times of that in winter, and that from fuel combustion in winter was 1.15-2.40 times of that in other seasons. CR from each source was sensitive to ingestion rate and skin adherence factor.

Pollution evaluation, human health effect and tracing source of trace elements on road dust of Dhanbad, a highly polluted industrial coal belt of India

Dust samples were collected from roads of five distinct types of land use zones (National Highway, residential areas, sensitive areas, mining areas, and busy traffic areas) of Dhanbad to determine the pollution characteristics, health risk, and identifying the source of trace elements. The dust samples were segregated into ≤ 60 µm and trace elements like Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn were analysed. Concentrations of Cd, Cr, Cu, Fe, and Mn were observed highest in the mining areas, whereas Ni, Pb, and Zn presented higher concentration values at National Highway and busy traffic zones. Cd showed highest geo-accumulation index (Igeo), contamination factor (Cf), and ecological risk (ER) among all the trace elements. The health risk assessment model was performed to assess the health effects of carcinogenic and non-carcinogenic pollutants caused due to multi-elemental exposure on adults and children. The significantly higher HQ (Hazard Quotient) and HI (Hazard Index) values posed by Cr, Fe, and Mn indicated potential non-carcinogenic risks to the people of Dhanbad. Similarly, values of CR (Cancer Risk) for Cd, Cr and Ni were within the range of 10^-6-10^-4, which indicated to cause carcinogenic risk to the population by the exposure of road dust. Principal Component Analysis (PCA) and Pearson correlation showed that coal mining activities in Jharia coalfield, coal-based industries like coke-oven plants, coal washeries and heavy vehicular load in the roads of Dhanbad were the major causes of emission of these trace elements.

Spatial distribution and sources of potentially toxic elements in road dust and its PM10 fraction of Moscow megacity

For the first time, the contents of potentially toxic elements (PTEs) in road dust and in its PM₁₀ fraction were studied in Moscow from June 09 to July 30, 2017 on roads with different traffic intensities, inside courtyards with parking lots, and on pedestrian walkways in parks. The contents of PTEs in road dust and PM₁₀ fraction were analyzed by ICP-MS and ICP-AES. The main pollutants of road dust and its PM₁₀ fraction included Sb, Zn, W, Sn, Bi, Cd, Cu, Pb, and Mo. PM₁₀ was a major carrier of W, Bi, Sb, Zn, Sn (accounts for >65% of their total contents in road dust); Cu (>50%); and Cd, Pb, Mo, Co, Ni (30-50%). PM₁₀ fraction was 1.2-6.4 times more polluted with PTEs than bulk samples. Resuspension of roadside soil particles accounted for 34% of the mass of PTEs in road dust and for 64% in the PM₁₀ fraction. Other important sources of PTEs were non-exhaust vehicles emissions (~ 20% for dust and ~14% for PM₁₀) and industrial emissions (~20% and ~6%). The road dust and PM₁₀ particles were most contaminated in the central part of the city due to the large number of cars and traffic congestions. Local anomalies of individual PTEs were observed near industrial zones mainly in the west, south, and southeast of Moscow. In the yards of residential buildings the total enrichment of road dust and PM₁₀ with PTEs was only 1.1-1.5 times lower than that on major roads which poses a serious danger to the population spending a significant part of their lives in residential areas. The spatial pattern of the PTEs distribution in road dust and its PM₁₀ fraction should assist in more efficient planning of washing and mechanical cleaning of the road surface from dust to minimize the risk to public health.

Urban Soils and Road Dust—Civilization Effects and Metal Pollution—A Review

Urban soils have been changed much by human impacts in terms of structure, composition and use. This review paper gives a general introduction into changes from compaction, mixing, water retention, nutrient inputs, sealing, gardening, and pollution. Because pollutions in particular have caused concerns in the past, metal pollutions and platinum group metal inputs have been treated in more detail. Though it is not possible to cover the entire literature done on this field, it has been tried to give examples from all continents, regarding geochemical background levels. Urban metal soil pollution depends on the age of the settlement, current emissions from traffic and industry, and washout. It seems that in regions of high precipitation, pollutants are swept away to the watershed, leaving the soils less polluted than in Europe. Health hazards, however, are caused by ingestion and inhalation, which are higher in 3rd world countries, and not by concentrations met in urban soils as such; these are not treated within this paper in detail. With respect to pollutants, this paper is focused on metals. Contrary to many reviews of the past, which mix all data into one column, like sampling depth, sieved grain sizes, digestion and determination methods, these have been considered, because this might lead to considerable interpretation changes. Because many datasets are not Gaussian distributed, medians and concentration ranges are given, wherever possible. Urban dust contains about two to three fold the hazardous metal concentrations met in urban soils. Some data about metal mobilities obtained from selective and sequential leaching procedures, are also added. Soil compaction, pollution, sealings and run-offs cause stress situations for green plants growing at roadside locations, which is discussed in the Section 5. Environmental protection measures have led to decrease metal pollutions within the last decade in many places.