Road Dust Samples Research Articles

Pollution characteristics and toxicity of potentially toxic elements in road dust of a tourist city, Guilin, China: Ecological and health risk assessment☆

Road dust samples from industrial, urban, and tourist areas of the international tourist city of Guilin, China, were collected to study the concentration, spatial distribution, pollution level, and health risk of potentially toxic elements (PTEs) using an array-based risk assessment model from the United States Environmental Protection Agency. The geoaccumulation index (Igeo), ecological risk index, and spatial interpolation were used to investigate the road dust pollution level. The results indicated that apart from Ni and Al, the concentration of all the heavy metals (Pb, Zn, Ni, Cu, Cr, Cd, Fe, Mn, and As) were markedly higher than the corresponding background values in the three functional areas. Based on the Igeo, the study area had an uncontaminated to moderate pollution level, and the industrial area was slightly more polluted and posed a greater ecological risk than the urban and tourist areas. Comparatively, Pb, Zn, and Cu exhibited higher pollution levels in the three functional sites. Hotspots of PTEs were more concentrated in urban and industrial areas than in tourist areas. Furthermore, the health risk model revealed significant non-carcinogenic risks to children from As in urban, industrial, and tourist areas as the hazard quotients (1.64, 2.04, and 1.42, respectively) exceeded the threshold standard of 1.00. The carcinogenic risk via ingestion (RIing) illustrated significant risks to children from Cr, As, and Ni because the RIing values were considerably higher than the threshold standard (1.00E-6 to 1.00E-4) in the three functional areas. However, no cancer risk was observed from the dermal and inhalation pathways.

Pollution status and human health risk assessment of potentially toxic elements and polycyclic aromatic hydrocarbons in urban street dust of Tyumen city, Russia.

This study investigated levels and sources of pollution and potential health risks associated with potentially toxic elements (PTEs) and polycyclic aromatic hydrocarbons (PAHs) in urban street dust collected from Tyumen city, a large transport centre with one of the highest motorization rates in Russia. Twenty street dust samples were collected from four grades of roads in five different land use areas. Research methods included measurements of physical and chemical properties of street dust, concentrations of 18 PTEs using inductively coupled plasma mass spectrometry, 12 PAHs using high-performance liquid chromatography, and statistical analysis of the data. Concentrations of Ni, Cr, Sb, and Mo, as well as medium and high molecular weight PAHs in urban street dust, were notably higher than in soils within the city, which indicates that transport is the main source of these elements. Concentrations of Cu, Cd, Pb, Zn, Mn, and As in street dust of Tyumen were lower compared to many large cities, while Cr, Ni, and Co were higher. Concentrations of PAH were comparable to other large nonindustrial cities. Total contamination of street dust by both PTEs and PAHs showed more robust relationships with the number of roadway lanes rather than land use. The estimated carcinogenic risks were low in 70% of samples and medium in 30% of samples. Noncarcinogenic risks were attributed to exposure to Co, Ni, V, and As. The total noncarcinogenic risk for adults was found to be negligible, while the risk was found to be moderate for children.

Background and fingerprint characteristics of anthropogenic 236U and137Cs in soil and road dust samples collected from Beijing and Zhangjiakou, China

236U has attracted more attention as an environmental tracer in recent years. However, in-depth study of 236U in terrestrial environments is still rare in China. Data on 236U and 137Cs concentrations in soil and road dust samples collected from Beijing and Zhangjiakou, China were obtained to demonstrate the background and distinct characteristics of anthropogenic 236U and 137Cs. 236U and 137Cs were detected in the range of (1.10–7.90) × 107 atoms g−1 and below the method limits of detection to 5.30 Bq kg−1. A clear characteristic was observed in road dust, where 236U concentrations increased with decreasing of sample particle size. Soil samples showed an irregular characteristic, but the highest 236U concentrations were observed in particle size fraction of <0.053 mm in both samples. This phenomenon was caused by U chemical properties, higher specific surface areas and organic compounds in fine particles. Anthropogenic radionuclides fingerprint characteristics in <0.053 mm samples were specially discussed. 236U/238U atom ratios were detected in the range of (0.627–3.38) × 10−8. A weak correlation between anthropogenic 236U and natural U isotopes were observed. The intermediate correlation between 236U and 137Cs indicated somewhat distinct migration behavior of these two radionuclides in soil after release to the environment. The released amount of 236U from global fallout during the period of atmospheric nuclear weapons testing was roughly estimated to be 1300 ± 448 kg. These results could be used as fingerprint information for anthropogenic 236U migration behavior and tracer application in environment.

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

There are many sources of urban road dust, such as soil dispersal, emissions of industrial enterprises and thermal power plants, road traffic-related processes. Chelyabinsk was selected as a typical Russian industrial city. This work was the first pollution study of road dust in Chelyabinsk. We examined 125 road dust samples were on the content toxic trace elements (As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Sb, Sr, and Zn). The concentrations of trace elements in road dust were determined using ICP-MS. Results showed that the metal concentrations in dust were higher than the background value of local soil. The distribution curves of dust were asymmetric, had have two peaks, and showed significant unimodal distribution. The higher share of particles was in the range from 30 … 40 to 250 … 300 μm. The thoracic fraction volume (%) and concentrations of trace elements were higher near metallurgical plants. Cadmium, Сu, Mn, Ni, Sr, Pb and Zn were originated from industry and transport; electrometallurgical plant was source of Cr; Al, Co, and Fe derived from local soils and pavement erosion; As, Hg and Sb were the tracers of coal-fired power stations emission. Ingestion was a major exposure way of toxic elements in the dust. The results suggested that there was no significant potential health risk to both children and adults from exposure to any elements in road dust. The cancer risk for adults and children from exposure to As, Cd, Cr, and Pb was found to be at the acceptable or tolerable level.The study deals with the contamination of potentially toxic trace elements (As, Cd, Co, Cr, Cu, Mn, Ni, Pb, Sb, Sr and Zn) in road dust collected from Chelyabinsk urban area.

Quantification of ytterbium in road dust applying slurry sampling and detection by high-resolution continuum source graphite furnace atomic absorption spectrometry

In this work, the determination of ytterbium in road dust samples, employing a simple and fast methodology, based on sample preparation as slurry and analysis by high resolution-continuum source graphite furnace atomic absorption spectrometry (HR-CS-GFAAS), is purposed. The determinations were carried out on the Yb main line, 398.799 nm, using an integration time of 5.0 s. The optimum condition for the slurry preparation of road dust samples was established through a Doehlert matrix for two variables, which employed a HNO3 concentration of 0.24 mol L−1 and homogenization time of 34 min, using ultrasonic bath. The temperatures applied to the graphite furnace were optimized, wherein the pyrolysis and atomization temperatures were 1200 °C and 2700 °C, respectively, using 250 μg of W as permanent chemical modifier. To investigate possible matrix interferences in the determination of Yb in road dust samples, external calibration and standard addition curves were compared. The comparison between slopes of the external and standard addition calibration curves showed difference of about 7.0%, an indication of absence of matrix effects for determination of Yb in road dust samples. The limit of detection (LOD) and limit of quantification (LOQ) were 22 and 72 ng g−1, respectively, with a characteristic mass of 6.0 pg. The accuracy was confirmed through analyses of three certified reference materials (CRM): Trace Elements in Soil Containing Lead From Paint (NIST 2586), Rock (NCS DC 73301) and Geochemical Soil (TILL-1), and the good agreement between the found and certified values was obtained, 99 ± 4 to 104 ± 2%, corroborating the accuracy of the analytical method. The precision was expressed as relative standard deviation (RSD) for measurements in triplicate, being lower than or equal to 10.0%. The analytical method was used for Yb determination in eight samples of dust collected in an urban area of Salvador and Jaguaquara, Bahia State, Northeast, Brazil. The concentrations obtained for Yb ranged from 172 ± 13 to 2065 ± 122 ng g−1. Thus, the proposed analytical method presents the characteristics of being fast, precise and accurate for the determination of Yb in road dust samples, employing slurry sampling and detection by HR-CS-GFAAS.

Polycyclic aromatic hydrocarbons and their nitro-derivatives in urban road dust across China: Spatial variation, source apportionment, and health risk

As an essential carrier of hazardous substances, fugitive road dust has become a severe issue in China. In this study, 212 road dust samples from 53 cities in China were collected to comprehensively investigate the spatial variations, potential sources, and cancer risk of 16 polycyclic aromatic hydrocarbons (PAHs) and 16 nitro-PAHs. The total PAHs concentrations ranged from 0.07 to 345 μg/g dry weight, which is at a moderate level compared to other regions in the world. The mean concentration of Σ16nitro-PAHs was 111 ± 115 ng/g, which is 2–3 orders of magnitude lower than that of Σ16PAHs. A clear geographical trend of dust PAHs and nitro-PAHs was observed in the northeast, north, and east coastal regions of China at a higher level. Moreover, a significant correlation between latitude and PAHs/nitro-PAHs revealed the influences of outdoor temperature and coal combustion for heating in the different regions on the emission and reaction of PAHs and nitro-PAHs. The secondary formation of most nitro-PAHs increases with a decrease in latitude indicated that solar radiation and temperature are important factors on secondary formation of nitro-PAHs. The average concentration of total PAHs and their derivatives in trunk road samples were statistically higher than those in other road samples (p < 0.05), indicating the influence of traffic load on target compound concentration. Generally, the primary sources of PAHs in the road dust samples were coal combustion (23.9%), vehicles (57.1%), and wood/biomass combustion (19.0%). For nitro-PAHs, the main sources were secondary formation (30.9%), biomass/coal combustion (28.4%), and vehicles (44.9%). Furthermore, a moderate potential carcinogenic risk due to PAHs and nitro-PAHs in the dust samples was found in China.

Concentrations of polycyclic aromatic hydrocarbons in street dust from bus stops in Qingyang city: Estimates of lifetime cancer risk and sources of exposure for daily commuters in Northwest China

Lifetime cancer risk and exposure of daily commuters to polycyclic aromatic hydrocarbons (PAHs) in cities of Northwest China were determined from a study of street dust samples obtained from bus stops in Qingyang city. The sum of 16 priority PAHs (Σ16 PAHs) concentrations in the dust samples ranged from 0.8 to 18.3 mg kg−1 (mean 3.0 mg kg−1) and the distribution of individual, carcinogenic, combustion specific, low (2–3 rings) and high molecular weight (4–6 rings) PAHs was determined. The benzo[a]pyrene toxic equivalents of Σ16 PAHs ranged from 0.01 to 12.2 mg kg−1 (mean 0.8 mg kg−1). Incremental lifetime cancer risk from exposure to PAHs in dust at bus stops in Qingyang city was estimated at 1.9 × 10−6 for adults and 3.5 × 10−6 for children (confidence limit ≥ 95%). Emission source analysis of PAHs in bus stop dust showed that they were mainly derived from residential coal, oil and biomass combustion, e.g. from boilers, traffic vehicles, and Kang heaters. Higher concentrations of PAHs were obtained at bus stops near transport hubs, commercial districts, and administrative institutions.

Fate of road-dust associated microplastics and per- and polyfluorinated substances in stormwater

Emerging contaminants such as microplastics (MPs) and per- and polyfluorinated substances (PFAS) in the water environment have been documented as the major environmental threat due to their negative impact on the ecosystem. Road dust has been recognised as a potential source of these emerging pollutants in stormwater which are eventually released into open water bodies. The aim of this study was to identify the existence of MPs and PFAS in Australian road dust and stormwater samples. We found that different MP types such as polyethylene, nylon, polyester and cotton were identified in the stormwater samples. The main type of MPs in stormwater was microfibres which accounted for more than 50 %. It was also found that PFAS was detected in Australian road dust from industrial and heavily trafficked areas. Although there was no PFAS in stormwater in the selected industrial and heavy traffic study area, they can be found in airport and defence sites. This study indicated that road dust acts as the potential origin of MPs and PFAS in urban stormwater runoff.

Spatial distribution of magnetic material in urban road dust classified by land use and type of road in San Luis Potosí, Mexico

Industrial and vehicular emissions of particles cause multiple damages to human health due to concentration, size, and composition. These emissions contain magnetic particles; therefore, low-cost properties allow tracking and monitoring them. This study is aimed at identifying the primary sources of magnetic material in 100 samples of urban road dust from San Luis Potosi, Mexico, analyzing the influence of land use and the type of road on these particles. Magnetic susceptibility (χlf) and isothermal remanent magnetization at 0.7 T (IRM0.7T) were determined, as well as the iron and manganese content using X-ray fluorescence. The distribution of particles was examined by land use and type of road through geostatistical maps and variance analysis. The results showed that the iron and manganese content, χlf, and IRM0.7T were positively correlated, indicating a possible common origin. The primary sources identified were the iron smelter and laminator in the industrial park. Urban land use influenced the content of iron, manganese, and magnetic material in urban road dust. The land uses with the more significant transformation (industrial and mixed) presented the highest values of iron, manganese, χlf, and IRM0.7T. On the other hand, vehicular traffic was indirectly assessed through the type of road, influencing the magnetic signal of urban road dust and finding the highest signals in primary and secondary roads. Then, the magnetic properties allowed the tracking and monitoring of magnetic particles from industrial and vehicle emissions.

Concentrations, Speciation, and Bioavailability of Heavy Metals in Street Dust as well as Relationships with Physiochemcal Properties: A Case Study of Jinan City in East China.

A total of 77 street dust samples were collected from Jinan City in East China and were analyzed for the concentrations, speciation, bioavailability, and influencing factors of ten heavy metals. The results showed that the average concentrations of Ba, Co, Cr, Cu, Cd, Mn, Ni, Pb, Zn, and V in the street dust were 642.77, 8.24, 114.09, 87.71, 1.08, 517.04, 30.29, 80.32, 497.84, and 51.76 mg/kg, and the concentrations of Ba, Cr, Cu, Cd, Ni, Pb, and Zn exceeded the local soil element background values. In the street dust, Ba, Co, Cr, Mn, Ni, and V were mainly in the residual; Cu and Pb were controlled by the oxidizable; Cd mainly existed in the acid extractable; and Zn was dominated by the reducible. According to the ratios of the acid extractable to the sum of four forms, Cd (39.85%) presented a high environmental risk; Mn and Zn (24.29% and 27.78%) exhibited a medium risk; and V, Cu, Pb, Ba, Co, Ni, and Cr had no environmental risk. The order of mobility or potential risk of heavy metals was Cd ( 85.8%) > Zn (77.1%) > Cu (64.3%) > Pb (62.0%) > Mn (51.7%) > Ba ( 38.9%) > Co (31.2%) > Ni (30.1%) > V (25.8%) > Cr (23.1%), suggesting that Cd, Zn, Cu, Pb, and Mn presented relatively high movability and risk. The bioavailability order of heavy metals was Cd (82.7%) > Zn (63.6%) > Mn (40.4%) > Ni (20.4%) > Pb (11.7%) > Cu (11.1%) > V (7.8%) > Cr (3.7%) in the gastric phase and Cu (24.6%) > Cd (19.9%) > Mn (16.2%) > Ni (6.6%) > Pb (5.7%) > Zn (4.4%) > Cr (3.0%) > V (2.3%) in intestinal phase, implying that Cd, Zn, Mn, and Cu were highly bioavailable in the gastrointestinal environment, which coincided with the risk of speciation. The speciation of heavy metals in street dust had certain correlations with their bioavailability. The physiochemical properties of street dust had significant effects on the concentrations, speciation, and bioavailability of heavy metals in street dust. The simple, fast, and nondestructive magnetic measurements could be used as indicators of the concentrations, speciation, and bioavailability of heavy metals in street dust.

Identifying environmental pollution recorded in street dust using the magnetic method: a case study from central eastern China.

Urban street dust constitutes important intermediate products for the transmission of solid organic and inorganic pollutants in the urban environment. In this study, 133 street dust samples were collected from Xinyang to explore their magnetic characteristics, spatial distribution, and environmental implications using magnetic measurements. The results are as follows. (1) There were ferrimagnetic, antiferrimagnetic, and paramagnetic (e.g., lepidocrocite) minerals in the dust. Among these, the dominant magnetic carriers were ferrimagnetic minerals. Furthermore, magnetite was a first-order ferrimagnetic carrier. (2) The magnetic domains of the dust were pseudo single-domain to multi-domain. (3) The magnetic concentration (χ and SIRM) of dust were 2.6 and 4.1 times higher than those of background samples that were not polluted by urban and anthropogenic activities, respectively. Therefore, we conclude that the dust consisted of high concentration of ferrimagnetic minerals and coarse magnetic particles. (4) The magnetic distribution was spatially different. The industrial area, which was the most polluted sampling area, had the highest magnetic concentration and the coarsest magnetic particles. This was attributable to industrial emissions, fossil fuel combustion, and exhaust emissions from heavy-laden trucks. Residential and commercial areas, which were the second most polluted areas, had higher concentration and coarser particles. This was primarily due to the high population density and traffic activities of mini-cars (i.e., high flux and exhaust emissions). Hence, the conclusion is that the magnetic characteristics, spatial distribution, and the sources of dust are dictated by anthropogenic activities. Our results indicate that the magnetic method is a highly effective tool to monitor urban environmental pollution.

Exposure of children to light rare earth elements through ingestion of various size fractions of road dust in REEs mining areas

Road dust, contains enhanced amounts of light rare earth elements (LREEs) in rare earth industrial cities, which poses a serious health risk particularly to children. Road dust samples were collected from Baotou, the largest rare earth industrial city in northern China, and sieved into six size fractions. The pollution characteristics of the LREEs (La, Ce, Pr, and Nd) in the size-fractioned road dust were investigated, and the LREEs exposure dose of children via ingestion of road dust was evaluated. The results showed that the finer size fractions of road dust had enhanced REEs concentrations, and the pollution level was found to be elevated with a decrease in particle size. Ce was the most abundant element, with concentrations ranging from 105 to 5420 mg·kg−1, followed by La, Nd and Pr. REEs mining activities had a major contribution to the LREEs in the road dust and crust, among which coal combustion emissions could also be a potential source. The average daily intake dose of LREEs through ingestion of road dust by children ranged from 4.27 × 10−4 to 2.63 × 10−2 mg·kg−1·day−1 and was significantly affected by particle size. Road dust exposure is notably affected by particle size, and there is a serious risk to children of LREEs uptake from fine particles (<100 μm) of road dust.

Carbon fractionation and stable carbon isotopic fingerprint of road dusts near coal power plant with emphases on coal-related source apportionment

Road dust from coal utilization is a significant source contributing to the generation of pollutants that can affect the health of people residing within close proximity to roadways. In this study, road dust samples were collected from different directions centered around a coal-fired power plant in Huainan. Black carbon (BC), soot, char, organic carbon (OC) and total carbon (TC), as well as the δ13C of samples, were determined. Compared to the reference locations which were distant from the power plant, the research areas surrounding the power plant were featured by significantly higher OC/BC ratio and TC concentration. The OC/BC showed significant difference in urban vs. rural areas, and at different distances from the central power plant, which implied that the source and spread of carbonaceous species was dominantly affected by wind direction and urban/rural area differences. Surface morphology analysis showed that the road dust was mixed with spherical particles similar to fly ash. High-resolution XPS C1s spectrum revealed the existence of metal carbide, metal carbonate, and CF3 in the road dust samples. The speciation of carbon in road dusts was found correlated with sampling directions and urban functional areas. Based on the δ13C and OC/BC, it could be inferred that coal-related substances might be important sources of road dusts.

Contamination characteristics of heavy metals in particle size fractions from street dust from an industrial city, Central China

In order to investigate the heavy metal pollution level and distribution characteristics in different particle sizes, and to evaluate the health risk, 42 street dust samples were collected in January 2015 from Huangshi, as an industrial city in Central China. The results analyzed by flame atomic absorption spectrometry (FAAS) showed that the average content of Cu, Pb, Zn, Cd, Mn, and Fe in the fine particle diameter (< 25 μm) was 1041.12, 361.64, 890.00, 14.43, 3178.52, and 61841.79 mg kg−1, respectively. Meanwhile, the average content of Cu, Pb, Zn, Cd, Mn, and Fe in the coarse particle diameter (25 < D < 75 μm) was 1628.54, 401.52, 593.16, 9.54, 5316.07, and 76765.37 mg kg−1, respectively. Compared with other cities, the heavy metal pollution of street dust in Huangshi was more serious. The results indicated that heavy metals were more easily enriched in fine grains street dust, except for Cu, Mn, and Fe. The heavy metal elements showed obvious spatial heterogeneity in different regions, and the interference from human sources was greater. Heavy metals in Huangshi street dust are generally at moderate or higher pollution levels (except Fe), of which Cu and Cd are the most seriously polluted. Multivariate statistical analysis shows that the heavy metals in fine-grained street dust mainly come from traffic/industrial mixed sources (74.5%) and industrial sources (25.5%); the heavy-grained street dust heavy metals mainly come from mixed traffic/industrial sources (55.1%) and soil source (44.9%). For non-carcinogenic heavy metals, mainly through the hand-mouth contact pathway into the human body, there are also no non-carcinogenic health risks in both hand-mouth ingestion and dermal contact. For carcinogenic heavy metals, Cd in street dust did not have carcinogenic risk.

Polycyclic aromatic hydrocarbon source fingerprints in the environmental samples of Anzali-South of Caspian Sea.

The major emission sources of polycyclic aromatic hydrocarbons (PAHs) in Anzali city, apportionment of these sources and transfer of PAHs through street dust and runoff to rivers and finally the Caspian Sea, were studied. PAHs in environmental samples including street dust, runoff, and river sediment samples as well as in major sources of hydrocarbons in urban area including vehicles exhaust, gasoline and diesel fuels, engine oils of automobiles and boats, asphalt, and tire debris were extracted by Soxhlet and liquid-liquid extraction in solid and liquid phase and were analyzed by GC-MS. Significance of each source in PAH emission in the area was identified by chemical fingerprinting. According to the spatial distribution of PAHs in receptor samples stations of street dust and runoff located in the center of the city with high traffic of vehicles had higher concentrations of PAHs than stations in the out bonds of the city. In the river sediment samples, the stations located in the port area had the highest concentrations of PAHs. Results of chemical fingerprinting showed that especially in street dust and runoff samples, the isometric patterns of PAHs were rather similar to those in the proposed major sources, showing that they may have been originated from them, especially from asphalt and tire. On the contrary, river sediment samples were confirmed to receive inputs from other unknown independent sources.

Chemical characteristics of road dust PM2.5 fraction in oasis cities at the margin of Tarim Basin

In order to understand the compositions characteristics of particulate matter with aerodynamic diameter less than 2.5 μm (PM2.5) fraction in road dust (RD2.5) of oasis cities on the edge of Tarim Basin, 30 road dust (RD) samples were collected in Kashi, Cele, and Yutian in the spring, 2018, and RD2.5 was collected using the resuspension approach. Eight water-soluble ions, 39 trace elements and 8 fractions of carbon-containing species in PM2.5 were analyzed. Ca2+ and Ca were the most abundant ions and elements in RD2.5 (7.1% and 9.5%). Cl- in RD2.5 was affected not only by attributed to saline-alkali soils in oasis cities of the Tarim Basin and dust from Taklimakan Desert but also by human activities. Moreover, the organic carbon/elemental carbon (OC/EC) ratio indicated that carbon components in RD2.5 in Cele town mainly come from fossil fuel combustion, while those in Yutian and Kashi mainly come from biomass combustion. It is noteworthy that high Ca in RD2.5 was seriously affected by anthropogenic emissions, and high Na and K contents in RD2.5 could be derived from soil and desert dust. It was estimated that Cd, Tl, Sn and Cr were emitted from anthropogenic emissions using the enrichment factor. The coefficients of divergence (COD) result indicated that the influence of local emission on road dust emission is greater than that of long-distance transmission. This study is the first time to comprehensively analyze the chemical characteristics of road dust in oasis cities, and the results provides the sources of road dust at the margin of Tarim Basin.

Temperature-controlled liquid–liquid microextraction using a biocompatible hydrophobic deep eutectic solvent for microextraction of palladium from catalytic converter and road dust samples prior to ETAAS determination

A simple method based on temperature-controlled liquid–liquid microextraction (TC-LLME) using a novel hydrophobic deep eutectic solvent (DES) was developed for preconcentration of palladium. Deep eutectic solvent based on phenyl salicylate (salol) and DL-menthol (1:1) was used as the extraction solvent. The control of temperature enhanced the dispersion of deep eutectic solvent and a homogeneous solution was made. Upon cooling the solution in an ice bath, a cloudy solution was formed. Afterwards, the mixture was centrifuged and the sediment phase was analyzed by Electrothermal Atomic Absorption Spectroscopy (ETAAS). To improve the extraction efficiency, the main parameters were optimized. Under the optimized extraction conditions, the limit of detection (LOD) and limit of quantification (LOQ) were 0.03 μg L−1 and 0.10 μg L−1 respectively. Preconcentration factor was obtained 191. The precision, expressed as the relative standard deviation (RSD, n = 10), found to be 4.6%. Finally, the method was an effective procedure for the determination of palladium in water, catalytic converter and road dust samples with acceptable extraction recoveries of 95.1% to 100.4%. The obtained results confirmed the ability of the developed method in the different samples.

Spatial distribution of pollution characteristics and human health risk assessment of exposure to heavy elements in road dust from different functional areas of Zhengzhou, China.

Road dust from different sources directly contacts the human body and has potential effects on public health. In this study, a total number of 87 road dust samples were collected at 29 sampling sites from five different functional areas (commercial area (CA), residential area (RA), educational area (EA), industrial area (IA), and park area (PA)) in Zhengzhou to study the contamination status, distribution, source identification, ecological risk assessment, and spatial distribution of human health risks due to eight heavy elements. The geo-accumulation index (Igeo) and pollution index (PI) revealed that there was very high contamination with Cd and Hg caused by atmospheric deposition, which should be paid special attention. Additionally, the source identification indicated that Cr, Ni, Cu, Zn, Cd, and Pb originate from anthropogenic activities related to traffic, and Hg can originate from medical equipment and agricultural chemicals, while the extremely low level of pollution with As could be explained by geographic sources. Moreover, the calculated ecological risk index values were increased in the order of CA > RA > EA > IA > PA in different functional areas. According to the human health risks of the whole city, children exposed to Pb have the highest health risk, especially for CA and IA, as calculated by the noncarcinogenic hazard index (HI). For adults and children, health risks caused by Cu, Zn, and Pb were higher in the CA, RA, and PA of the downtown area, whereas Cr and Ni had the highest noncarcinogenic exposure risk in northwestern Zhengzhou due to point source pollution. Calculations of the carcinogenic risk (CR) values for Cr, Ni, As, and Cd indicate that the value of Cr is highest (1.17 × 10-7), especially inside the industrial area (8.55 × 10-7), which is close to the lower limit of the threshold values (10-6 to 10-4). These results can provide a theoretical basis and data support for air treatment, pollution control, and the implementation of public prevention in different functional areas of Zhengzhou.

Variation of the chemical composition of street dust in a highly industrialized city in the interval of ten years

Street dust can be re-suspended into the atmosphere by wind and vehicle passage in an urban area. Street dust is affecting the environmental quality of the atmosphere and human health. A detailed study was conducted to determine the changes in concentrations of heavy metals and magnetic susceptibility by comparison of samples of street dust obtained in the years 2008 and 2018 at the same localities. An amount of dust per m2 of road area was highly variable for individual localities (47 g/m2 – 1.37 kg/m2), with arithmetic mean (229.7 ± 85.97 g/m2) in the year 2018. Silt particles in street dust (<0.063 mm) represented approx. 15–20%, sand particles approx. 63–70% and gravel 10–20%. Iron (5–6%) has significant concentrations in street dust. The highest concentrations are represented by the series Mn ˃ Zn ˃ Cr ˃ Cu ˃ Pb ˃ Ni. Comparison of metal concentrations in the years 2008 and 2018 showed a comparable level of iron and a lower level of lead. The significant enrichment was found for Cu, Cr and Zn expressed by enrichment factor in the range from 5 to 20. High values of magnetic susceptibility of street dust are caused by metallurgy. Metals except Cu are bound in magnetic particles and have a high correlation coefficient with magnetic susceptibility.

Assessment of Trace Elements in Urban Road Dust of a City in a Border Province Concerning Their Levels, Sources, and Related Health Risks.

Most research studies regarding the contamination of urban road dust (RD) focused on mega cities, but little consideration is given for small cities in border areas. The present work investigated the trace elements content in 16 RD samples of particle size < 63μm at six areas with different anthropogenic activities in Sakaka city, KSA. The trace elements were analyzed using XRF and ICP-MS. Significantly high trace elements concentrations were recorded at small-scale industrial area. Concentrations of trace elements are ranked as Fe > Mn > Pb > Zn > Cr > Cu > Co > As > Se. The contamination evaluation through enrichment factor calculation refers to the existence of an anthropogenic source for certain trace elements, such as Fe, Zn, Mn, Cu, and Pb. The values of contamination factor indicate the contamination of RD samples collected from small-scale industrial area with these trace elements. The highest pollution load index value recorded at this industrial area suggests that it is a highly polluted area. This was confirmed by applying the one-way ANOVA test for the difference analysis between the investigated areas. The correlation between most of the detected trace elements at the small scale-industrial area was lost due to the variation in their industrial sources. The health risk of some detected trace elements was estimated for two groups of populations, namely workers at the small scale-industrial area and residents (adults and children) at residential areas at this city under study. Workers and resident children were more likely affected by arsenic through the ingestion pathway to cancer because of its higher cancer risk values that were more than the acceptable value 1 × 10-6. Workers and residents (adults and children) are susceptible to noncarcinogenic risks through the ingestion pathway of Fe because of its higher hazard quotient values that are more than one.