Potential sources and health risk assessment of polycyclic aromatic hydrocarbons in street dusts of Karaj urban area, northern Iran

Assessment of potential ecological risk for polycyclic aromatic hydrocarbons in urban soils with high level of atmospheric particulate matter concentration

Polycyclic aromatic hydrocarbons (PAHs) are known to be representative carcinogenic environmental pollutants with high toxicity. However, information on the potential ecological and environmental risks of PAH contamination in soil remains scarce. Thus, this study was evaluated the potential ecological risks of PAHs in soils of five Korean areas (Gunsan (GS), Gwangju, Yeongnam, Busan, and Gangwon) using organic carbon (OC)-normalized analysis, mean effect range-median quotient (M-ERM-Q), toxic equivalent quantity (TEQ) analysis, and risk quotient (RQ) derived by the species sensitivity distribution model. In this study, atmospheric particulate matter has a significant effect on soil pollution in GS through the presence of hopanes and the similar pattern of PAHs in soil and atmospheric PAHs. From analysis of source identification, combustion sources in soils of GS were important PAH sources. For PAHs in soils of GS, the OC-normalized analysis, M-ERM-Q, and TEQ analysis have 26.78 × 105 ng/g-OC, 0.218, and 49.72, respectively. Therefore, the potential ecological risk assessment results showed that GS had moderate-high ecological risk and moderate-high carcinogenic risk, whereas the other regions had low ecological risk and low-moderate carcinogenic risk. The risk level (M-ERM-Q) of PAH contamination in GS was similar to that in Changchun and Xiangxi Bay in China. The Port Harcourt City in Nigeria for PAH has the highest risk (M-ERM-Q = 4.02 and TEQ = 7923). Especially, compared to China (RQPhe =0.025 and 0.05), and Nigeria (0.059), phenanthrene showed the highest ecological risk in Korea (0.001-0.18). Korea should focus on controlling the release of PAHs originating from the PM in GS.

Polycyclic aromatic hydrocarbons in dust from rural communities around gas flaring points in the Niger Delta of Nigeria: an exploration of spatial patterns, sources and possible risk

Indoor and outdoor dust from three rural communities (Emu-Ebendo, EME, Otu-Jeremi, OTJ, and Ebedei, EBD) around gas flaring points, and a rural community (Ugono Abraka, UGA) without gas flare points, in the Niger Delta of Nigeria, was analysed for the concentrations and distribution of polycyclic aromatic hydrocarbons (PAHs), their sources, and possible health risk resulting from human exposure to PAHs in dust from these rural communities. The PAHs were extracted from the dust with a mixture of dichloromethane/n-hexane by ultrasonication, and purified on a silica gel/alumina packed column. Gas chromatography-mass spectrometry was employed to determine the identity and concentrations of PAHs in the cleaned extracts. The Σ16PAH concentrations in the indoor dust ranged from 558 to 167 000, 6580 to 413 000, and 2350-37 500 μg kg-1 for EME, OTJ and EBD respectively, while those of their outdoor counterparts varied from 347 to 19 700, 15 000 to 130 000, and 1780 to 46 300 μg kg-1 for EME, OTJ and EBD respectively. On the other hand, the UGA community without gas flare points had Σ16PAH concentrations in the range of 444-5260 μg kg-1 for indoor dust, and 154-7000 μg kg-1 for outdoor dust. The lifetime cancer risk values for PAHs in these matrices surpassed the acceptable limit of 10-6 suggesting a potential carcinogenic risk resulting from human exposure to PAHs in indoor and outdoor dust from these rural communities. Principal component analysis suggested that PAH contamination of dust from these communities arises principally from gas flaring, combustion of wood/biomass, and vehicular emissions.

Polyaromatic hydrocarbon thin film layers on glass, dust, and polyurethane foam surfaces

An investigation was conducted into the dynamic behavior of two polyaromatic hydrocarbon (PAH) semi-volatile organic compound (SVOC) naphthalene (NAP) and benzo [ghi]perylene (BghiP) in air and on various surfaces including glass, dust, and polyurethane foam (PUF) to understand their interaction with different media. A confocal fluorescence microscope and an infrared microscope were employed to detect and monitor the concentration-, time-, and temperature-dependent changes of the aromatic NAP and BghiP species on the surfaces. Infrared two-dimensional mapping of the vibrational characteristic peaks was used to track the two PAHs on the surfaces. Gas chromatography-mass spectrometry (GC-MS) was employed to measure the gaseous concentrations. The sorption of NAP and BghiP on the surfaces was estimated using Arizona desert sand fine (ISO 12103-1 A2) dust and organic contaminant household (SRM 2585) dust. The surface-to-air partition coefficients of NAP and BghiP were estimated on the different surfaces of glass, dust, and PUF. Molecular dynamic simulations were performed on dust surfaces based on the Hatcher model to understand the behavior of NAP and BghiP on dust surfaces. The Weschler-Nazaroff model was introduced to predictPAH film accumulation on the surfaces, providing a better understanding of PAH interaction with different environmental media. These findings could contribute to developing effective strategies to mitigate the adverse impact of PAHs on the environment and human health.

Contamination, probabilistic health risk assessment and quantitative source apportionment of potentially toxic metals (PTMs) in street dust of a highly developed city in north of Iran

Street dust (SD) are the particulates that primarily originated from Earth's crust and secondary alteration and erosion of natural and anthropogenic materials. The multi-dimensional pollution and health risk assessment of potentially toxic metals (PTMs) in these particles remain unknown in the majority of world urban areas. The elemental concentration, mineralogy, and micro-morphology of street dust were determined by inductively coupled plasma mass spectrometry (ICP-MS), SEM-EDX, XRD, and petrographical observation. Multivariate statistical analysis combined with positive matrix factorization (PMF) and Monte-Carlo simulations were applied to source identification and health risk assessment of PTMs. A severe enrichment of Sb, Cu and Zn and moderate contamination of Sn, Pb, and Cr were observed in the samples particularly in the areas with higher loads of traffic. The results of geochemical indices showed that K, Al, Mn, and V have natural/geogenic origins. While Sb, Pb, Cr, Cu, and Zn showed an enrichment relative to the background values with dominant anthropogenic sources. The results were confirmed by source appointment techniques. The results of deterministic and probabilistic health risk assessment by Monte-Carlo simulations revealed the non-carcinogenic nature of As, Mn, and Pb for children mainly through skin and ingestion routes. It can be concluded that the chemical compound of street dust in Gorgan city is affected by both natural (loess deposits) and anthropogenic sources. Also, children are in the risk of exposure to PTMs in street dust more than adults.

Polycyclic aromatic hydrocarbons in road dusts of a densely populated African city: spatial and seasonal distribution, source, and risk assessment

Road dust is a principal source and depository of polycyclic aromatic hydrocarbons (PAHs) in many urban areas of the world. Hence, this study probed the spatial and seasonal pattern, sources, and related cancer health risks of PAHs in the road dusts sampled at ten traffic intersection (TIs) of a model African city. Mixed PAHs sources were ascertained using the diagnostic ratios and positive matrix factorization (PMF) model. The results showed fluctuations in mean concentrations from 36.51 to 43.04 µg/g. Three-ring PAHs were the most abundant PAHs with anthracene (Anth) ranging from 6.84 ± 1.99 to 9.26 ± 4.42 µg/g being the predominant pollutant in Ibadan. Benzo(k)Fluoranthene (BkF) which is a pointer of traffic emission was the most dominant among the seven carcinogenic PAHs considered, varying from 2.68 ± 0.43 to 4.59 ± 0.48 µg/g. Seasonal variation results showed that PAH concentrations were 20% higher during dry season than rainy season. The seven sources of PAHs identified by PMF model include the following: diesel vehicle exhausts, gasoline combustion, diesel combustion, coal tar combustion, gasoline vehicle exhausts, coal and wood (biomass) combustion, and emissions from unburnt fossil fuels. Employing the incremental lifetime cancer risk (ILCR) model, the city's cancer risk of 5.96E-05 for children and 6.60E-05 for adults were more than the satisfactory risk baseline of ILCR ≤ 10^-6 and higher in adults than in Children.

Trends, Issues and Future Directions of Urban Health Impact Assessment Research: A Systematic Review and Bibliometric Analysis

Health impact assessment (HIA) has been regarded as an important means and tool for urban planning to promote public health and further promote the integration of health concept. This paper aimed to help scientifically to understand the current situation of urban HIA research, analyze its discipline co-occurrence, publication characteristics, partnership, influence, keyword co-occurrence, co-citation, and structural variation. Based on the ISI Web database, this paper used a bibliometric method to analyze 2215 articles related to urban HIA published from 2012 to 2021. We found that the main research directions in the field were Environmental Sciences and Public Environmental Occupational Health; China contributed most articles, the Tehran University of Medical Sciences was the most influential institution, Science of the Total Environment was the most influential journal, Yousefi M was the most influential author. The main hotspots include health risk assessment, source appointment, contamination, exposure, particulate matter, heavy metals and urban soils in 2012–2021; road dust, source apposition, polycyclic aromatic hydrocarbons, air pollution, urban topsoil and the north China plain were always hot research topics in 2012–2021, drinking water and water quality became research topics of great concern in 2017–2021. There were 25 articles with strong transformation potential during 2020–2021, but most papers carried out research on the health risk assessment of toxic elements in soil and dust. Finally, we also discussed the limitations of this paper and the direction of bibliometric analysis of urban HIA in the future.

Source identification and risk assessment of polycyclic aromatic hydrocarbons (PAHs) in air and dust samples of Lahore City

During two consecutive summer and winter seasons in Lahore, the health risk of air and dust-borne polycyclic aromatic hydrocarbons (PAHs) was evaluated. Gas chromatography/mass spectrometry (GS/MS) was used to determine air and dust samples from various functional areas across the city. The mean ∑₁₆PAHs were higher in air 1035.8 ± 310.7 (pg m^-3) and dust 963.4 ± 289.0 (ng g^-1 d.w.) during winter seasons as compared to summer seasons in air 1010.9 ± 303.3 (pg m^-3) and dust matrices 945.2 ± 283.6 (ng g^-1 d.w.), respectively. PAHs ring profile recognized 3 and 4 rings PAHs as most dominant in air and dust samples. Estimated results of incremental lifetime cancer risk (ILCR) highlighted high carcinogenic risk among the residents of Lahore via ingestion and dermal contact on exposure to atmospheric PAHs. The total ILCR values in air among children (summer: 9.61E - 02, winter: 2.09E - 02) and adults (summer: 1.45E - 01, winter: 3.14E - 02) and in dust, children (summer: 9.16E - 03, winter: 8.80E - 03) and adults (summer: 1.38E - 02, winter: 1.33E - 02) during the study period. The isomeric ratios in the study area revealed mixed PAH sources, including vehicular emission, petroleum, diesel and biomass combustion. As a result, it is advised that atmospheric PAHs should be monitored throughout the year and the ecologically friendly fuels be used to prevent PAHs pollution and health concerns in the city. The findings of this study are beneficial to the local regulating bodies in terms of controlling the exposure and promoting steps to reduce PAHs pollution and manage health in Lahore.

Dilution of PAHs loadings of particulate matter in air, dust and rivers in urban areas: A comparative study (Tehran megacity, Iran and city of Tübingen, SW-Germany)

PAHs (polycyclic aromatic hydrocarbons) in urban areas are usually bound to particles. Concentrations are different in different compartments (airborne particles, street dust, suspended sediments in rivers and channels). This study follows concentrations of PAHs from particles in air to street dust and finally suspended sediments in the city of Tehran, Iran compared to Tübingen, Germany. Data sets are based on own investigations (PAHs on suspended sediments), or taken from literature studies (PAHs in street dust and airborne particles). Based on a cross-comparison of concentrations of PAHs on particles, and their congener distribution patterns, the occurrence, interrelation (exchange and mixing processes), as well as possible dilution processes among PAHs in the different particle classes are disentangled. Results show that for Tehran and Tübingen PAHs in airborne particles are very high (in the range of 500 mg kg^-1). However, in street dust and suspended sediments PAHs concentrations on particles are around 100 times lower. Surprisingly concentrations in street dust and suspended sediments are 5 to 10 times lower in Tehran (average 0.5 mg kg^-1) than in Tübingen (average 5 mg kg^-1). Since it is unlikely that PAHs emissions are lower in the Tehran megacity, an effective dilution of the atmospheric signal by uncontaminated (background) particles is hypothesized. Uncontaminated particles may stem from wind erosion of bare surfaces, construction and sand mining sites or even dust from the desert areas, which are frequent in arid climate in Tehran.

The effect of PM2.5-related hazards on biomarkers of bronchial epithelial cells (A549) inflammation in Karaj and Fardis cities

Fine particles (especially PM2.5 particles) in ambient air can cause irreversible effects on human health. In the present study, seasonal variations in toxicity PM2.5 (cell viability and release of pro-inflammatory cytokines) were exposed human lung cells (A549) to concentrations of PM2.5 samples in summer (sPM2.5) and winter (wPM2.5) seasons. Cells were separately exposed to three concentrations of PM2.5 (25, 50, and 100 μg/mL) and three times (12 h, 1 and 2 days). We evaluated cell viability by MTT assay [3- (4, 5-dimethylthiazol-2-yl) -2, 5-diphenyltetrazolium bromide] and liberation of pro-inflammatory cytokines (interleukin-6 and interleukin-8) by the ELISA method. The toxicological results of this study showed that increasing the concentration of PM2.5 particulates and contact time with it reduces cell viability and increases inflammatory responses. Seasonal cytotoxicity of PM2.5 particles in high-traffic areas at summer season compared to winter season was lower. The lowest percent of viability at 2 days of exposure and 100 μg/mL exposure in the winter sample was observed. Also, PM2.5 particles were influential in the amount of interleukins 8 and 6. The average release level of IL-6 and IL-8 in the cold season (winter) and the enormous exposure time and concentrations (2 days-100 μg/mL) was much higher than in the hot season (summer). These values were twice as high for winter PM2.5 samples as for summer samples. The compounds in PM2.5 at different seasons can cause some biological effects. The samples' chemical characteristics in two seasons displayed that the PMs were diverse in chemical properties. In general, heavy metals and polycyclic aromatic hydrocarbons were more in the winter samples. However, the samples of wPM2.5 had a lower mass quota of metals such as aluminum, iron, copper, zinc, and magnesium. Concentrations of chromium, cadmium, arsenic, mercury, nickel, and lead were more significant in the sample of wPM2.5.

Occurrence and source apportionment of polycyclic aromatic hydrocarbons (PAHs) in dust of an emerging industrial city in Iran: implications for human health

Polycyclic aromatic hydrocarbons (PAHs) bounded to street dust are a severe environmental and human health danger. This study provides preliminary information on the abundance of PAHs in street dust from Rafsanjan city, Iran, where industrial emissions are high and data are lacking. Seventy street dust samples were collected from streets with different traffic loads. The United States Environmental Protection Agency (USEPA) Standard Methods 8270D and 3550C were used for the measurement of PAHs using GC mass spectroscopy. The total concentration of PAHs was 1443 ng g-1, with a range of 1380-1550 ng g-1. Additionally, the concentration of carcinogenic PAHs (∑carcPAHs) ranged from 729.5 to 889.4 ng g-1, with a mean value of 798.1 ng g-1. Pyrene was the most abundant PAH, with an average concentration of 257 ng g-1. Source identification analyses showed that vehicle emissions along with incomplete combustion and petroleum were the main sources of PAHs. The ecological risk status of the studied area was moderate. Spatial distribution mapping revealed that the streets around the city center and oil company had higher PAH levels than the other sectors of Rafsanjan. The results indicated that dermal contact and ingestion of contaminated particles were the most important pathways compared to inhalation. The mean incremental lifetime cancer risk (ILCR) was 1.4 × 10-3 and 1.3 × 10-3 for children and adults, respectively. This implies potentially adverse health effects in exposed individuals. The mutagenic risk for both subpopulations was approximately 18 times greater than the one recommended by USEPA. Our findings suggest that children are subjected to a higher carcinogenic and mutagenic risk of PAHs, especially dibenzo[a,h]anthracene (DahA), bounded to street dust of Rafsanjan. Our study highlights the need for the development of emission monitoring and control scenarios.

The partitioning behavior of PAHs between settled dust and its extracted water phase: Coefficients and effects of the fluorescent organic matter

The occurrence and distribution of polycyclic aromatic hydrocarbons (PAHs) in a city of Central China were determined in the settled dust and its extracted water phase from different land use types and bus stops in Nanchang City. The physicochemical properties of its water extracted dissolved organic matter (WEOM) were characterized to investigate the effect of fluorescence organic matter on the dust-water partitioning coefficients (K_d) using three-dimensional excitation-emission matrix fluorescence spectroscopy combined parallel factor analysis. Results showed that the range of ∑PAHs in settled dust and the extracted water phase was 0.05-15.92 μg·g^-1 and 2-211 ng·L^-1, respectively. These PAHs mostly came from the combustion of biomass. The risk assessment showed that PAHs in dust had no obvious health risk (less than the magnitude of 10^-6). Additionally, the high molecular weight (HMW) PAHs and the low molecular weight (LMW) PAHs were preferentially adsorbed by dust and the dissolved portion, respectively. It was confirmed by the relatively high logK_d values of 4.23 for the HMW-PAHs. Pearson correlation analysis suggested that the higher concentration of dissolved organic carbon and humic-like substance were in favor of PAHs in dust released into waters. This study can provide information on pollution control when considering the impact of fluorescent organic matter on the fate and transport of PAHs.

Impact of Land-Use Types on the Distribution and Exposure Risk of Polycyclic Aromatic Hydrocarbons in Dusts from Benin City, Nigeria

The concentrations of the sixteen United States Environmental Protection Agency polycyclic aromatic hydrocarbons (PAHs) were determined in dusts from different land-use types in Benin City by means of gas chromatography-mass spectrometry. The results obtained were used to assess the ecological and human health risk and to determine the source apportionment. The Ʃ16 PAH concentrations in dusts from Benin City ranged from 230 to 2300 µg kg^-1 for industrial areas, 211-1330 µg kg^-1 for commercial areas, 153-1170 µg kg^-1 for residential areas, and from 216 to 1970 µg kg^-1 for school playgrounds/parks. The ecological risk assessment suggested that the levels of PAHs in dusts from these land-use types are of low-to-moderate risk to organisms. The benzo(a)pyrene carcinogenic potency [BaP_TEQ] (70.5-131 µg kg^-1) and benzo(a)pyrene mutagenic potency [BaP_MEQ] (62.9-122 µg kg^-1) concentrations were below the Canadian soil quality guideline value of 600 µg kg^-1. The incremental lifetime carcinogenic risk (ILCR) arising from exposure of adults and children to PAHs in dusts from Benin City were in the magnitude of 10^-4-10^-2, which exceeded the safe target levels of 10^-6, implying a considerable cancer risk for residents of this city. The PAH source apportionment derived from isomeric ratios and multivariate statistics indicated that burning of biomass, wood, and charcoal, and vehicular traffic were the predominant sources of PAHs in dusts from Benin City.

Determination of Polycyclic Aromatic Hydrocarbons and Their Methylated Derivatives in Sewage Sludge from Northeastern China: Occurrence, Profiles and Toxicity Evaluation

This paper assesses the occurrence, distribution, source, and toxicity of polycyclic aromatic hydrocarbons (PAHs), and their methylated form (Me-PAHs) in sewage sludge from 10 WWTPs in Northeastern China was noted. The concentrations of ∑PAHs, ∑Me-PAHs ranged from 567 to 5040 and 48.1 to 479 ng.g−1dw, which is greater than the safety limit for sludge in agriculture in China. High and low molecular weight 4 and 2-ring PAHs and Me-PAHs in sludge were prevalent. The flux of sludge PAHs and Me-PAHs released from ten WWTPs, in Heilongjiang province, was calculated to be over 100 kg/year. Principal component analysis (PCA), diagnostic ratios and positive matrix factorization (PMF) determined a similar mixed pyrogenic and petrogenic source of sewage sludge. The average values of Benzo[a]pyrene was below the safe value of 600 ng.g−1 dependent on an incremental lifetime cancer risk ILCR of 10⁻⁶. Sludge is an important source for the transfer of pollutants into the environment, such as PAHs and Me-PAHs. Consequently, greater consideration should be given to its widespread occurrence.

Concentrations of selected monohydroxy polycyclic aromatic hydrocarbons across various stages of glomerular function

The objective of this study was to evaluate the variabilities in the concentrations of selected monohydroxy polycyclic aromatic hydrocarbons (OH-PAH) in urine across various stages of glomerular function. Data from National Health and Nutrition Examination Survey for US adult smokers (N = 3125) and nonsmokers (N = 6793) were selected for analysis to meet the objectives of the study. OH-PAHs selected for analysis were as follows: 1-hydroxynaphthalene, 2-hydroxynaphthalene, 2-hydroxyfluorene, 3-hydroxyfluorene, 9-hydroxyfluorene, 1-hydroxyphenanthrene, 2-hydroxyphenanthrene, 3-hydroxyphenanthrene, and 1-hydroxypyrene. Stages of glomerular function (GF) considered were as follows: hyperfiltrators (GF-1A, eGFR ≥ 110 mL/min/1.73 m²), normal filtrators (GF-1B, 90 < eGFR < 110 mL/min/1.73 m²), GF-2 (60 ≤ eGFR < 90 mL/min/1.73 m²), GF-3A (45 ≤ eGFR < 60 mL/min/1.73 m²), and GF-3B/4 (15 ≤ eGFR < 45 mL/min/1.73 m²). For the analysis of data for smokers, however, data for GF-3A and GF-3B/4 were merged because of small sample sizes for these GF stages for smokers. Among nonsmokers, (i) there was almost a straight-line decrease in adjusted concentrations of 2-hydroxyfluorene, 3-hydroxyfluorene, 9-hydroxyfluorene, 1-hydroxyphenanthrene, 2-hydroxyphenanthrene, 3-hydroxyphenanthrene, and 1-hydroxypyrene over GF-1A through GF-3B/4; (ii) concentrations of these OH-PAHs at GF-3B/4 varied from being 37.5% for 1-hydroxypyrene to being 87% for 9-hydroxyfluorene of what they were at GF-1A; and (iii) while concentrations of 1-hydroxynaphthalene were located on an inverted U-shaped curve, concentrations of 2-hydroxynaphthalene were located on a U-shaped curve with pints of inflections at GF-3A. Among smokers, concentrations of all nine OH-PAHs in urine were located on inverted U-shaped curves with points of inflections located at GF-2 and concentrations of these OH-PAHs at GF-3/4 varied from being 48.7% for 1-hydroxypyrene to being 116.1% for 9-hydroxyfluorene of what they were at GF-1A. The kidneys differ in how they process urinary metabolites of PAHs among smokers and nonsmokers.