Seasonal occurrence and cancer risk assessment of polycyclic aromatic hydrocarbons in street dust from the Novi Sad city, Serbia

Development of a needle trap device packed with modified PAF-6-MNPs for sampling and analysis of polycyclic aromatic compounds in air

The aim of this study was to develop a new method for sampling and analyzing polycyclic aromatic hydrocarbons in the air. This was achieved by utilizing a needle trap device packed with a modified porous aromatic framework coated with magnetic nanoparticles (PAF-6-MNPs). The modified adsorbent underwent qualitative evaluation using Fourier-transform infrared spectroscopy and X-ray diffraction, as well as scanning and transmission electron microscopy. The optimal conditions for sampling polycyclic aromatic hydrocarbons compounds were determined using a dynamic atmosphere chamber. The method was validated by taking various samples from the standard chamber, and then analyzed under different environmental sampling conditions using a gas chromatography device. The limit of detection (LOD) and limit of quantification (LOQ) values for the analytes of interest, including naphthalene, anthracene, and pyrene, ranged from 0.0034-0.0051 and 0.010-0.015 μg L-1, respectively. Also, the repeatability and reproducibility of the method expressed as relative standard deviation, for the mentioned analyses were found to be in the range of 17.8-20.5% and 20-22.9%. The results indicated that over a 20 day storage period (with the needle trap device containing the analytes of interest kept in the refrigerator), there was no significant decrease in the amount of analytes compared to the initial amount. These findings suggest that, the needle trap packed with the proposed adsorbent offers a reliable, highly-sensitive, easy-to-use, and cost-effective method for sampling polycyclic aromatic hydrocarbons in the air compared to the conventional method recommended by the National Institute of Occupational Safety and Health (NIOSH), method 5515.

Chemical and genotoxic characterization of bioaccessible fractions as a comprehensive in vitro tool in assessing the health risk due to dust-bound contaminant ingestion

In the last two decades, awareness grew on the matter of the impact of environment on human health. Contaminants sorbed onto soil and settled dust can be ingested and thus represent a hazard, particularly to young children, who play on the ground and bring their hands and objects to their mouth. Metal(loid)s and polycyclic aromatic hydrocarbons (PAHs) are of concern as they are both carcinogenic to humans and ubiquitous in outdoor environments. The present study aims to assess the total and bioaccessible fractions of PAHs and metal(loid)s present in settled dust of four preschools located in industrial, urban, and suburban areas. On the one hand, children's incremental life cancer risks (ILCR) were calculated according to ingestion pathway. On the other hand, the genotoxicities of the bioaccessible dust-bonded contaminants were determined on gastric cells. PAH concentrations ranged from 50.9 to 2267.3 ng/g, and the bioaccessible fraction represented 10.7% of the total in average. Metal(loid) concentration ranged from 12,430 to 38,941 µg/g, and the mean bioaccessibility was of 40.1%. Cancer risk ranged from 2.8.105 to 8.6.105, indicating that there is a potential cancer risk for children linked to the ingestion of settled dust. The inorganic bioaccessible fraction induced little DNA (< 20%TailDNA) and chromosomal damages (30% increase in micronuclei), whereas the organic bioaccessible fraction induced higher DNA (17-63%TailDNA) and chromosomal damages (88% increase in micronuclei). Such experimental approach needs to be deepen, as a tool complementary to cancer risk calculation, since the latter only lays on a set of targeted contaminants with known toxicity values.

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.

Toward an interdisciplinary approach to assess the adverse health effects of dust-containing polycyclic aromatic hydrocarbons (PAHs) and metal(loid)s on preschool children

Settled dust can function as a pollutant sink for compounds, such as polycyclic aromatic hydrocarbons (PAHs) and metal(loid)s (MMs), which may lead to health issues. Thus, dust represents a hazard specifically for young children, because of their vulnerability and hand-to-mouth behavior favoring dust ingestion. The aim of the present study was to explore the influence of the season and the microenvironment on the concentrations of 15 PAHs and 17 MMs in indoor and outdoor settled dust in three preschools (suburban, urban, and industrial). Second, the potential sources and health risks among children associated with dust PAHs and MMs were assessed. Third, domestic factors (risk perception, knowledge and parental style) were described to explore protective parental behaviors toward dust hazards. The suburban preschool had the lowest concentrations of dust PAHs and MMs, while the industrial and urban preschools had higher but similar concentrations. Seasonal tendencies were not clearly observed. Indoor dusts reflected the outdoor environment, even if specific indoor sources were noted. Source analysis indicated mainly vehicular emissions, material release, and pyrogenic or industrial sources. The non-cancer health risks were non-existent, but potential cancer health risks (between 1.10-6 and 1.10-4) occurred at all sampling locations. Notably, the highest cancer risk was observed in a playground area (>1.10-4) and material release should be further addressed. Whereas we assessed higher risk indoors, parents perceived a higher risk in the open-air environment and at the preschool than at home. They also perceived a lower risk for their own children, revealing an optimism bias, which reduces parental anxiety.

Integrative assessment of urban dust polycyclic aromatic hydrocarbons using ground and satellite data in Iran

Recently, for quick urbanization and industrialization, pollutants, especially urban dust, have posed many threats to the human environment. Polycyclic aromatic hydrocarbons (PAHs) are regarded as the main dangerous pollutants that are widespread, persistent, and carcinogenic. The present work aimed to investigate the contamination and sources of PAHs, as well as to assess the risk of cancer for 16 priority PAHs, in urban dust samples in Ahvaz, Isfahan, and Shiraz cities in Iran. We measured PAH concentrations by gas chromatography-mass spectrometry (GC-MS). The average concentrations of the 16 PAHs in Ahvaz, Isfahan, and Shiraz were 6215.11, 7611.03, and 7810.37 μg kg-1, respectively. The domination of low-molecular-weight (LMW) PAHs was observed in Ahvaz, while maximum contribution was observed for high-molecular-weight (HMW) PAHs in Esfahan and Shiraz. For PAHs' source identification, diagnostic ratio, correlation analysis, clustering, and positive matrix factorization (PMF) model were used. PAHs had a combustion (coal and wood, oil, fossil fuels) and gasoline/diesel engine emissions in all cities. Comparative studies suggest that the PAH compounds' level is higher in the research area than in other countries, except for China and India. Also, the pollution of urban dust PAHs has increased over time compared to previous studies in the same cities. The cancer risk from exposure to dust contaminated with PAHs was assessed using the Incremental Lifetime Cancer Risk (ILCR) model. According to the findings, a high risk of exposure to cancer was observed in Ahvaz, Isfahan, and Shiraz. However, compared to adults, children are at higher risk of cancer in their daily lives via dermal contact and unconscious ingestion. Based on the ILCR values, the risk of cancer is in the order of Shiraz > Isfahan > Ahvaz. To assess air pollutants and their effects on urban dust, TROPOMI onboard the Sentinel-5P data were used in the studied cities during 2018-2021. The results show that Ahvaz has different high levels of CO compared to the other 2 cities. Also, Isfahan has different high levels of NO2 compared to the other 2 cities, but Shiraz has different low levels of O3. According to satellite time series data, the trend of the Aerosol Absorbing Index (AAI) has been increasing, while there was a decreasing trend in AAI from the beginning of the COVID-19 pandemic until 12 months later. Therefore, the natural and anthropogenic sources of urban dust PAHs have been increasing in all studied cities. Our findings show that PAH compounds in urban dust pose a significant threat to human health. Therefore, strategic management and planning are vital in reducing urban dust pollution.

Occurrence, Sources, and Health Risks of Polycyclic Aromatic Hydrocarbons in Road Environments from Harbin, a Megacity of China

To obtain a comprehensive understanding about that occurrence, sources, and effects on human health of polycyclic aromatic hydrocarbons (PAHs) in road environmental samples from Harbin, concentrations of 32 PAHs in road dust, green belt soil, and parking lot dust samples were quantified. The total PAH concentrations ranged from 0.95 to 40.7 μg/g and 0.39 to 43.9 μg/g in road dust and green belt soil, respectively, and were dominated by high molecular weight PAHs (HMW-PAHs). Despite the content of PAHs in arterial roads being higher, the composition profile of PAHs was hardly influenced by road types. For parking lot dust, the range of total PAH concentrations was 0.81-190 μg/g, and three-ring to five-ring PAHs produced the maximum contribution. Compared with surface parking lots (mean: 6.12 μg/g), higher total PAH concentrations were detected in underground parking lots (mean: 33.1 μg/g). The diagnostic ratios of PAHs showed that petroleum, petroleum combustion, and biomass/coal combustion were major sources of PAHs in the samples. Furthermore, according to the Incremental Lifetime Cancer Risk model, the cancer risks of three kinds of samples for adults and children were above the threshold (10-6). Overall, this study demonstrated that PAHs in the road environment of Harbin have a certain health impact on local citizens.

Inventory, source and health risk assessment of nitrated and parent PAHs in agricultural soils over a rural river in Southeast China

Nitrated polycyclic aromatic hydrocarbons (NPAHs) have become a concerning topic because of their widespread occurrence and carcinogenicity. However, studies on NPAHs in soils, especially in agricultural soils, are still limited. In this study, a systematic monitoring campaign of 15 NPAHs and 16 polycyclic aromatic hydrocarbons (PAHs) was performed in agricultural soils from the Taige Canal basin in 2018, which is a typical agricultural activity area of the Yangtze River Delta. The total concentration of NPAHs and PAHs ranged from 14.4 to 85.5 ng g^-1 and 118-1108 ng g^-1, respectively. Among the target analytes, 1,8-dinitropyrene and fluoranthene were the most predominant congeners accounting for 35.0% of ∑₁₅NPAHs and 17.2% of ∑₁₆PAHs, respectively. Four-ring NPAHs and PAHs were predominant, followed by three-ring NPAHs and PAHs. NPAHs and PAHs had a similar spatial distribution pattern with high concentrations in the northeastern Taige Canal basin. The soil mass inventory of ∑₁₆PAHs and ∑₁₅NPAHs was evaluated to be 31.7 and 2.55 metric tons, respectively. Total organic carbon had a significant impact on the distribution of PAHs in soils. The correlation between PAH congeners in agricultural soils was higher than that between NPAH congeners. Based on diagnostic ratios and principal component analysis-multiple linear regression model, vehicle exhaust emission, coal combustion, and biomass combustion were the predominant sources of these NPAHs and PAHs. According to the lifetime incremental carcinogenic risk model, the health risk posed by NPAHs and PAHs in agricultural soils of the Taige Canal basin was virtually negligible. The total health risk in soils of the Taige Canal basin to adults was slightly higher than that to children.

Levels, distribution, sources and children health risk of PAHs in residential dust: A multi-city study in China

BACKGROUND

Polycyclic aromatic hydrocarbons (PAHs) are typical residential pollutants mainly from biofuel combustion that impose inevitable risk to children. The PAHs in residential dust is universal in most Chinese households with an obvious public health concern.

METHODS

In this observational study, a total of 235 residential dust samples from 8 Chinese cities (Panjin, Shijiazhuang, Lanzhou, Luoyang, Xi'an, Wuxi, Mianyang, and Shenzhen) were collected from April 2018 to March 2019, which were extracted and analyzed for 16 priority PAHs by HPLC/FD-UV. Diagnostic ratios, hierarchical clustering analysis and principal component analysis were applied simultaneously for source apportionments. Incremental lifetime cancer risk was employed to estimate children's health risks based on the assumed exposure scenarios. Spearman correlation, Mann-Whitney U test, Kruskal-Wallis H test and Partial Least Squares were used to screen the factors affecting the concentration of PAHs in residential dust.

RESULTS

The median concentration of ∑₁₆PAHs in residential dust from 8 cities was 44.11 μg/g (0.04 - 355.79 μg/g). ∑₁₆PAHs were found both higher in dust samples in heating season and from downwind households only in Mianyang (p < 0.05). The leading two sources of PAHs were combustion processes and automobile exhaust emissions based on four principal components that accounted for 74.29 % of the total variance. Indoor air environmental factors, household characteristics, and residents' behavioral lifestyles may be the influencing factors of residential dust PAHs. The carcinogenic risk of children aged 0 - 5 years, under the moderate exposure level of PAHs in residential dust, exceeded the acceptable level (10^-5 - 10^-4 for dermal contact and 10^-6 - 10^-5 for ingestion).

CONCLUSIONS

There was serious PAHs pollution in residential dust under actual living conditions in eight cities across China. More evidence-based measures were needed to control PAHs pollution to safeguard children's health according to appointed sources and influencing factors in residential dust.

Identifying proxies and mapping heavy metals concentrations in city road dusts: A case study in the Brussels-Capital Region, Belgium

This paper investigates the spatial distribution of heavy metals (HMs) concentrations in road dusts over a part of the Brussels-Capital Region (BCR), with the aim of identifying the most relevant factors impacting these concentrations and subsequently mapping them over all road segments. For this goal, a set of 128 samples of road dusts was collected over a three years time span in the Anderlecht municipality, that covers about a tenth of the BCR area. The concentrations of Cd, Cr, Cu, Ni, Pb and Zn have been measured in the finest fraction ( ⌀ < 250 μm) using ICP-OES. In parallel, continuous and categorical-valued proxies have been collected over all road segments. Using a multivariate linear modeling (MLR) approach, the most influential proxies that have been identified are the distance to the center of the BCR, land use, road hierarchy and roadside parking occupation. The performance of the MLR models remains however limited, with adjusted R 2 values around 0.5 for all HMs. From a spatial analysis of the regression residuals, it is likely that some useful proxies could have been overlooked. Although these models have clear limitations for reliably predicting HMs concentrations at specific locations, the corresponding maps drawn over all road segments provide a useful overview and help designing sound monitoring policies as well appropriate implementation of mitigation measures at places where road dust pollutants tend to concentrate. Further studies are needed to confirm this, but it is expected that our models will perform reasonably well over a large part of the BCR. It is believed too that our findings are relevant for modeling road dusts pollution in other cities as well.

Gas Particle Partitioning of PAHs Emissions from Typical Solid Fuel Combustions as Well as Their Health Risk Assessment in Rural Guanzhong Plain, China

Air pollutants from the incomplete combustion of rural solid fuels are seriously harmful to both air quality and human health. To quantify the health effects of different fuel-stove combinations, gas and particle partitioning of twenty-nine species of polycyclic aromatic hydrocarbons (PAHs) emitted from seven fuel-stove combinations were examined in this study, and the benzo (a) pyrene toxicity equivalent (BaPeq) and cancer risks were estimated accordingly. The results showed that the gas phase PAHs (accounting for 68-78% of the total PAHs) had higher emission factors (EFs) than particulate ones. For all combustion combinations, pPAHs accounted for the highest proportion (84.5% to 99.3%) in both the gas and particulate phases, followed by aPAHs (0.63-14.7%), while the proportions of nPAHs and oPAHs were much lower (2-4 orders of magnitude) than pPAHs. For BaPeq, particulate phase PAHs dominated the BaPeq rather than gas ones, which may be due to the greater abundance of 5-ring particle PAHs. Gas and particle pPAHs were both predominant in the BaPeq, with proportions of 95.2-98.6% for all combustion combinations. Cancer risk results showed a descending order of bituminous coal combustion (0.003-0.05), biomass burning (0.002-0.01), and clean briquette coal combustion (10^-5-0.001), indicating that local residents caused a severe health threat by solid fuel combustion (the threshold: 10^-4). The results also highlighted that clean briquette coal could reduce cancer risks by 1-2 orders of magnitude compared to bulk coal and biomass. For oPAH, BcdPQ (6H-benzo(c,d)pyrene-6-one) had the highest cancer risk, ranging from 4.83 × 10^-5 to 2.45 × 10^-4, which were even higher than the total of aPAHs and nPAHs. The dramatically high toxicity and cancer risk of PAHs from solid fuel combustion strengthened the necessity and urgency of clean heating innovation in Guanzhong Plain and in similar places.

Source risk, ecological risk, and bioeffect assessment for polycyclic aromatic hydrocarbons (PAHs) in Laizhou Bay and Jiaozhou Bay of Shandong Peninsula, China

In order to incorporate the contribution of pollution sources to ecological risks into environmental monitoring, positive matrix factorization-risk quotient (PMF-RQ) was used to quantify the contribution of different PAH sources to ecological risks, which indicated that the unburned petroleum, vehicular emissions, and diesel combustion were the main sources of PAHs in Laizhou Bay and Jiaozhou Bay, and they were caused by petrochemical industry, maritime shipping, and urban traffic exhaust as the major sources of PAHs for ecological risk. Meanwhile, integrated biomarker response (IBR) and multi-biomarker pollution index (MPI) suggested that September was the most polluted month for PAHs in Laizhou Bay and Jiaozhou Bay and the pollution in Laizhou Bay was significantly higher than that in Jiaozhou Bay. This research was dedicated to explore the monitoring pattern for PAH pollution from the source to bioeffects, and it may have contributed a scientific support to monitoring and governance of marine PAH pollution.

A case study on the occurrence of polycyclic aromatic hydrocarbons in indoor dust of Serbian households: Distribution, source apportionment and health risk assessment

This study was conducted in order to obtain the first insight into the occurrence, potential sources, and health risks of polycyclic aromatic hydrocarbons (PAHs) in indoor dust. Samples (n = 47) were collected from households in four settlements in the northern Serbian province of Vojvodina. Total concentrations of 16 EPA priority PAHs in the dust samples varied from 140 to 8265 μg kg^-1. Mean and median values for all samples were 1825 and 1404 μg kg^-1, respectively. According to the international guidelines for indoor environment, PAH content can be regarded as normal (<500 μg kg^-1) for ∼6% of the samples, high (500-5000 μg kg^-1) for ∼87% of the samples, and very high (5000-50000 μg kg¹) for ∼6% of the samples. In all settlements, PAHs with 4 rings were the most prevalent (accounting for 40-53% of the total PAHs). They were followed by 3-ringed PAHs (29-40%), which indicates rather uniform PAH profiles in the analyzed dust. Based on diagnostic ratios, principal component analysis (PCA), and positive matrix factorization (PMF), pyrogenic sources, such as vehicle emissions and wood combustion were the dominant sources of PAHs in analyzed samples. Health risk assessment, which included incidental ingesting, inhaling and skin contact with PAHs in the analyzed dust, was evaluated by using the incremental lifetime cancer risk (ILCR) model. Median total ILCR was 3.88E-04 for children, and 3.73E-04 for adults. Results revealed that major contribution to quite high total ILCRs was brought by dermal contact and ingestion. Total cancer risk for indoor dust indicated that 85% of the studied locations exceeded 10-4. This implies risk of high concern, with potential adverse health effects. The results are valuable for future observation of PAHs in indoor environment. They are also useful for regional authorities who can use them to create policies which control sources of pollution.

Polycyclic aromatic hydrocarbons in street dust from different functional areas in Chengdu, China: seasonal variation and health risk assessment

This is the first investigation that identified seasonal variation, possible sources and health risk of 16 PAHs in street dust sampled park area (PA), educational area (EA), commercial area (CA), residential area (RA), and traffic area (TA) of Chengdu, one of the new first-tier cities in China. The total PAHs (∑₁₆PAHs) concentrations of averaging over two seasons varied from 2.15 to 10.6 mg/kg with a median value of 4.61 mg/kg and in winter (5.48 ± 1.52 mg/kg) were significantly higher than that in summer (4.04 ± 0.91 mg/kg). The highest ∑16PAHs concentration was found in TA (median 6.74 mg/kg). Statistical analysis results indicated that mixture sources of petroleum combustion and combustion of biomass and coal seem to be the primary source of the PAHs in street dust. Carcinogenic risk by incremental lifetime cancer risk (ILCR) model for PAHs in street dust indicates an acceptable potential cancer risk for residents. The same sequences of cancer risk to be observed for both children and adults among different functional areas: TA > CA > EA > RA > PA. The results provided advice for habitants in Chengdu to encourage outdoor activities in parks and residential areas and minimize traffic areas and commercial areas.

Seasonal source identification and source-specific health risk assessment of pollutants in road dust

Humans who are exposed to metals in road dust may have potential health risks through touching, ingesting, and inhaling the suspended road dust. There were limited studies to link seasonal emission sources to health risks from metals in road dust. In this study, metals in road dust from different functional areas were seasonally monitored. The contributions of the pollutant sources in study areas varied with seasons. By combining the source apportionment model (PMF), road dust emission model, and health risk models (HI: hazard index and ILCR: incremental lifetime carcinogenic risk), industrial and construction activity was identified as the crucial source of both the pollutants in road dust (29-47%), and the HI for adults (27-45%) and children (41-50%) in different seasons. The traffic non-exhaust emission dominated in the carcinogenic risks for children in spring (45%) and summer (36%). Factors such as seasons, particle size, metal bioavailability, human exposure time, and exposure area were all taken into consideration to avoid overestimating or underestimating health risks. The carcinogenic risks for children (1.6 E-06) and adults (2.8 E-06) exposed to Cr both exceed the minimum threshold (10^-6). It means that the potential risks were acceptable but could not be completely neglected. Measured metals mainly posed hazard to human health through ingestion route. Pb and Mn, Fe and Mn were the main harmful elements that induced non-carcinogenic risks for adults and children, respectively. Effectively identifying the source-specific health risks in different seasons will help in the formulation of adaptive strategies to diminish the potential risks.

Seasonal occurrence, source apportionment, and cancer risk assessment of PAHs in the second largest international holy metropolitan: Mashhad, Iran

Street dust resuspension is one of the main sources of particulate matter with impacts on air quality, health, and climate. This research was aimed to determine the concentration, source, and health risk of polycyclic aromatic hydrocarbons (PAHs) in street dust of Mashhad city. To this end, USEPA-regulated 16 PAHs were measured in 84 dust samples using gas chromatography coupled to mass spectrometry (GC-MS). The source of Σ16PAHs was identified using diagnostic ratios (DRs), positive matrix factorization (PMF), and principal component analysis (PCA). The measured Σ16PAHs demonstrated different spatial concentrations (from 1,005 to 9,138.96 μg kg-1) and showed higher levels in summer (1,206.21-9,138.96 μg kg-1), although 4-ring PAHs exhibited maximum levels in both summer and winter. The findings revealed that the dust-deposited PAHs are predominantly emitted through combustion of fossil fuels (such as diesel and gasoline) and natural gas. The total incremental lifetime cancer risk (ILCR) was assessed by considering three possible exposure routes separately for children and adults and calculated carcinogenic risk values of 2.24E-06 and 2.14E-06, respectively. ILCR is above the baseline value (1.0E-06) for children and adults in both seasons.

Occurrence, source apportionment, and carcinogenic risk assessment of polycyclic aromatic hydrocarbons in urban road dusts in Shanghai

Polycyclic aromatic hydrocarbons (PAHs), as a class of important environmental pollutants, have received considerable concern due to their widespread existence and biological toxicity. The main purpose of this study was to determine concentrations, spatial distribution, possible sources, and potential health risk of PAHs in urban road dust in Shanghai, China. The concentration of Σ₂₆PAHs ranged from 53.0 to 28,700 ng g^-1 in road dust samples from Shanghai, which is at the low to medium level compared with other areas around the world. PAHs with 4-5 rings were predominant components in road dust. The level of PAHs in road dust was significantly higher than those in soil and river sediment in Shanghai. Six possible sources of PAHs were apportioned by PMF model. The contribution of pyrogenic PAHs accounted for 91.3% of the total PAHs in road dusts. The motor vehicular emission, natural gas, and coal combustion were main sources for urban road dust PAHs from Shanghai. Four dibenzopyrene (DBP) isomers were contributed averagely 75% of total TEQ_BaP concentration. DBalP, BaP, DBaiP, BbF, and DBA were main contributors to total carcinogenic potency, which totally contributed from 69.6 to 91.8% (median 89.1%) to total TEQ_BaP in urban road dusts of Shanghai. The results of incremental lifetime carcinogenic risk (ILCR) assessment showed that the total risk values exposed to 24 PAHs in road dust were lower than 10^-4 at all sampling sites, indicating that exposure to dust-bound PAHs at present level was unlikely to result in high carcinogenic risk for both children and adults in Shanghai.

Occurrence of Phthalates in Bottled Drinks in the Chinese Market and Its Implications for Dietary Exposure

Ubiquitous occurrences of phthalic acid esters (PAEs) or phthalates in a variety of consumer products have been demonstrated. Nevertheless, studies on their occurrence in various types of bottled drinks are limited. In this study, fifteen PAEs were analyzed in six categories of bottled drinks (n = 105) collected from the Chinese market, including mineral water, tea drinks, energy drinks, juice drinks, soft drinks, and beer. Among the 15 PAEs measured, DEHP was the most abundant phthalate with concentrations ranging from below the limit of quantification (LOQ) to 41,000 ng/L at a detection rate (DR) of 96%, followed by DIBP (DR: 88%) and DBP (DR: 84%) with respective concentration ranges of below LOQ to 16,000 and to 4900 ng/L. At least one PAE was detected in each drink sample, and the sum concentrations of 15 PAEs ranged from 770 to 48,004 ng/L (median: 6286 ng/L). Significant differences with respect to both PAE concentrations and composition profiles were observed between different types of bottled drinks. The median sum concentration of 15 PAEs in soft drinks was over five times higher than that detected in mineral water; different from other drink types. Besides DEHP, DBIP, and DBP, a high concentration of BMEP was also detected in a tea drink. The estimated daily dietary intake of phthalates (EDI_drink) through the consumption of bottled drinks was calculated based on the concentrations measured and the daily ingestion rates of bottled drink items. The EDI_drink values for DMP, DEP, DIBP, DBP, BMEP, DAP, BEEP, BBP, DCP, DHP, BMPP, BBEP, DEHP, DOP, and DNP through the consumption of bottled mineral water (based on mean concentrations) were 0.45, 0.33, 12.5, 3.67, 2.10, 0.06, 0.32, 0.16, 0.10, 0.09, 0.05, 0.81, 112, 0.13, and 0.20 ng/kg-bw/d, respectively, for Chinese adults. Overall, the EDI_drink values calculated for phthalates through the consumption of bottled drinks were below the oral reference doses suggested by the United States Environmental Protection Agency (U.S. EPA).

A review on analysis methods, source identification, and cancer risk evaluation of atmospheric polycyclic aromatic hydrocarbons

Polycyclic aromatic hydrocarbons (PAHs) have gained attention because of their environmental persistence and effects on ecosystems, animals, and human health. They are mutagenic, carcinogenic, and teratogenic. The review provides background knowledge about their sources, metabolism, temporal variations, and size distribution in atmospheric particulate matter. The review article briefly discusses the analytical methods suitable for the extraction, characterization, and quantification of nonpolar and polar PAHs, addressing the challenges. Herein, we discussed the molecular diagnostic ratios (DRs), stable carbon isotopic analysis (SCIA), and receptor models, with much emphasis on the positive matrix factorization (PMF) model, for apportioning PAH sources. Among which, DRs and PCA identified as the most widely employed method, but their accuracy for PAH source identification has received global criticism. Therefore, the review recommends compound-specific isotopic analysis (CSIA) and PMF as the best alternative methods to provide detailed qualitative and quantitative source analysis. The compound-specific isotopic signatures are not affected by environmental degradation and are considered promising for apportioning PAH sources. However, isotopic fractions of co-eluted compounds like polar PAHs and aliphatic hydrocarbons make the PAHs isotopic fractions interpretation difficult. The interference of unresolved complex mixtures is a limitation to the application of CSIA for PAH source apportionment. Hence, for CSIA to further support PAH source apportionment, fast and cost-effective purification techniques with no isotopic fractionation effects are highly desirable. The present review explains the concept of stable carbon isotopic analysis (SCIA) relevant to PAH source analysis, identifying the techniques suitable for sample extract purification. We demonstrate how the source apportioned PAHs can be applied in assessing the health risk of PAHs using the incremental lifetime cancer risk (ILCR) model, and in doing so, we identify the key factors that could undermine the accuracy of the ILCR and research gaps that need further investigation.

Comprehensive characterization of PAHs profile in Serbian soils for conventional and organic production: potential sources and risk assessment

This study presents a comprehensive characterization of occurrence and levels of 16 polycyclic aromatic hydrocarbons (PAHs) in arable soils used for conventional and organic production in northern and central part of Serbia as well as cross-border region with Hungary. Furthermore, this study includes a characterization of PAH sources and carcinogenic/non-carcinogenic human health risk for PAHs accumulated in analysed arable soils. The total concentration of 16 PAHs varied between 55 and 4584 µg kg^-1 in agricultural soil used for conventional production and between 90 and 523 µg kg^-1 in agricultural soil used for organic production. High molecular weight (HMW) PAHs were dominant compounds with similar contribution in both soil types (86% and 80% in conventional and in organic soil, respectively). Principal component analysis and diagnostic ratios of selected PAHs were used for identification of PAH sources in the analysed soils. Additionally, positive matrix factorization was applied for quantitative assessment. The results indicated that the major sources of PAHs were vehicle emissions, biomass and wood combustion, accounting for ~ 93% of PAHs. Exposure of farmers assessed through carcinogenic (TCR) and non-carcinogenic (THQ) risk did not exceed the acceptable threshold (TCR < 10^-6 and THQ < 1). Oral ingestion was the main exposure route which accounted for 57% of TCR and 80% of THQ. It was followed by dermal contact. This investigation gives a valuable data insight into the PAHs presence in arable soils and reveals the absence of environmental and health risk. It also acknowledges the importance of comprehensive monitoring of these persistent pollutants.

Distribution, sources and exposure risk of polycyclic aromatic hydrocarbons in soils, and indoor and outdoor dust from Port Harcourt city, Nigeria

In this study, we evaluated the concentrations, composition, sources, and potential risks of polycyclic aromatic hydrocarbons (PAHs) in soils, and indoor and outdoor dust from Port Harcourt city in Nigeria. Gas chromatography-mass spectrometry (GC-MS) was used for the detection and quantification of PAH species in the samples. The concentrations of the US EPA 16 PAHs plus 2-methyl-naphthalene (∑17 PAHs) in soils, and indoor and outdoor dust from Port Harcourt city ranged from 240 to 38 400, 276 to 9130 and 44 to 13 200 μg kg^-1 (dry weight, d.w.) respectively. The PAH concentrations in these matrices followed the sequence: soil > indoor dust > outdoor dust. The composition of PAHs in soils and dust (indoor and outdoor) showed remarkable differences with prominence of 3- and 5-ring PAHs. The estimated carcinogenic risk to the residents arising from exposure to these concentrations of PAHs in soils, and indoor and outdoor dust from Port Harcourt was above the acceptable target cancer risk value of 10^-6. We concluded that these sites require clean-up, remedial actions and implementation of stringent pollution control measures with the intention of reducing the undesirable impacts of PAHs on both the ecosystem and humans.

Occurrence, source identification, and ecological risk assessment of polycyclic aromatic hydrocarbons in sediments of the Pearl River Delta, China

The pollution characteristics, sources, and ecological risk of polycyclic aromatic hydrocarbons (PAHs) in surface sediment samples from the river networks and outlets of the Pearl River Delta (PRD) were investigated. The total PAH concentrations were in the range of 69.1-1297 ng g^-1 in river networks and 56.6-617 ng g^-1 in river outlets. The results of source identification showed that PAHs in sediments were mainly derived from combined sources of coke tar and liquid fossil fuel combustion, coal/wood combustion, and petroleum contamination. The ecological risks of PAHs were evaluated based on sediment quality guidelines (SQG), mean probable effects levels quotient values (PEL-Q), and the toxicity equivalence factor (TEQ_BaP) method. The ecological risks of PAHs in sediments were at moderate levels in the Pearl River Delta. Although no high risk was found, regular and continuous monitoring of PAHs in sediments needs to be performed.

On the nature of polycyclic aromatic hydrocarbons associated with sporting walkways dust: Concentrations, sources and relative health risk

Sporting walkways (SW) are a new innovation which may prove popular in many cities. As there is currently no information on possible health risks associated with their use, concentrations of polycyclic aromatic hydrocarbons (PAHs) associated with deposited dust sampled on SW in Jeddah, Saudi Arabia, have been measured and interpreted in relation to sources and cancer risk. The average ∑PAHs (16 compounds) ranged between 1357 ng/g in residential areas and 3764 ng/g in central urban areas, with suburban areas between. The congener profile and diagnostic ratios of PAHs indicate a predominant source associated with petroleum combustion (pyrogenic source), most probably vehicular emissions. Carcinogenic potential is estimated from the sum of carcinogenic compound concentrations weighted by their individual potency relative to benzo(a)pyrene, and is found to be similar to household dust sampled in the same city, and lower than many other indoor and outdoor (road) dusts sampled across the world.

Assessment of epigenotoxic profiles of Dongjiang River: A comprehensive of chemical analysis, in vitro bioassay and in silico approach

This research explored the occurrence, epigenetic toxic profiling and main toxic pollutants of POPs in surface water of Dongjiang River, southern China. The concentrations of selected POPs including polycyclic aromatic hydrocarbons (PAHs), endocrine disrupting chemicals (EDCs), phthalate esters (PAEs) and polybrominated diphenyl ethers (PBDEs) of surface water from 18 sites were investigated. ∑₁₆PAHs and ∑₄EDCs were at a moderate level, while ∑₆PAEs and ∑₆PBDEs had low pollution levels. PAHs, EDCs and PAEs showed higher concentrations in dry season than those in wet season, and the loading of selected POPs in tributaries was higher than those in mainstream due to intensive manufactures and lower runoff volume. Moreover, activities of DNA methyltransferase (DNMT)1, histone deacetylase (HDAC2, HDAC8) were confirmed to be sensitive indicators for epigenetic toxicity. The DNMT1-mediated epigenetic equivalency toxicity of organic extracts in Dongjiang River were more serious than those of HDAC2 and HDAC8. Correlation analysis shown binding affinity between POPs and DNMT1, HDAC2 and HDAC8 could be regarded as toxic equivalency factors. Risk assessment suggested that 4-nonylphenol and bisphenol A were the largest contributors to epigenetic risk. This study is the first attempt to quantify epigenetic toxicity and epigenetic risk evaluation of river water.

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.

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.

Phase distribution and risk assessment of PAHs in ambient air of Hamadan, Iran

In the present study, both gaseous and particulate (PM with dae <2.5 µm) phases of polycyclic aromatic hydrocarbons (PAHs) were measured in the ambient air of Hamadan city, Iran. For this reason, two low-volume samplers equipped with glass fiber filters were used for sampling of particulate phase (N = 30) and XAD-2 sorbent tubes were applied for sampling gaseous phase of PAHs (N = 30). The sampling was conducted during warm and cold seasons in 2019. The average of cold/warm season ratios for Σ₁₆PAH and PM concentrations were 1.14 and 0.62, respectively. Summed PAHs concentration were determined to be in the range 0.008-59.46 (mean: 11.61) ng/m³ and 0.05-40.83 (mean: 10.22) ng/m³ for the cold and warm seasons, respectively. A negative Pearson correlation coefficient was obtained for wind speed and relative humidity. The average Benzo (a) Pyrene equivalent carcinogenic (BaP_eq) levels in the cold season were lower than the maximum permissible risk level of 1 ng/m³ for BaP. The BaP toxicity equivalency (ΣBaP_TEQ) and BaP mutagenicity equivalency (ΣBaP_MEQ) appeared to be significantly higher in the cold season (averaging 0.35 and 1.65 ng/m³, respectively) than those in warm season. Health risk assessment was performed for children and adults based on BaP_eq, inhalation cancer risk. The diagnostic ratios of individual PAHs concentration showed that the significant sources of PAH emissions may be related to light duty vehicles (LDVs) in Hamadan. Although, some other sources such as pyrogenic source and petrol combustion were also suggested.

Spatio-temporal variation and risk assessment of polycyclic aromatic hydrocarbons (PAHs) in surface dust of Qom metropolis, Iran

The objective of this research was to determine seasonal variation, distribution, potential health risk, and source identification of 16 polycyclic aromatic hydrocarbons (PAHs) in the surface dust of eight urban areas of Qom. The total levels of 16 PAHs ranged from 364.83 to 739.26 ng g^-1, with an average of 478.27 ng g^-1. Sites 1 and 8 showed the highest (491.33 ng g^-1) and lowest (465.08 ng g^-1) concentrations of PAHs, respectively. The PAHs demonstrated the highest and the lowest levels in autumn (553.41 ng g^-1) and summer (402.30 ng g^-1), respectively. Naphthalene (Nap) showed the highest amounts in all of the areas (75.57 ng g^-1). Source apportionment indicated that vehicular emissions and combustion of fossil fuels (liquid fossil fuel, crude oil, and gas) are the main sources of the PAHs. Toxic equivalency quantities (TEQs) index exhibited a mean concentration of 47.41 ng g^-1, and benzo[a]pyrene (BaP) and dibenzo[a,h]anthracene (DBA) together contributed more than 80% of TEQ, indicating high risk potential of these compounds. Total incremental lifetime cancer risk (ILCR) presented higher value (2.62 × 10^-7) for children than for adults (2.53 × 10^-7), one-fold lower than the threshold (10^-6). The spatial ILCR for the study areas and seasons showed the highest cancer risk in site 2 and winter. Taken together, the carcinogenic risk of PAHs to children and adults, respectively, through direct ingestion and dermal contact pathways illustrated values close to the baseline, suggesting that more attention should be paid to the issue in the study area.

Health risk assessment in urban parks soils contaminated by metals, Rio Grande city (Brazil) case study

Soils and artificial surfaces of urban parks can be contaminated by toxic substances and offer risk to the human health, especially to children. Rio Grande city, southern Brazil, is a peculiar site from the point of view of environmental contamination, since the current levels of contamination reflect an accumulation of different polluting sources started in the 18th century up to the urban and industrial sources of the present. The history of Hg contamination refers to the use of Hg salts in textile activities in the 18th century and the consequent use of contaminated sediments to land urban areas. The current contamination involves metals such as Cu, Ni, Pb and Zn is related to the high degree of urbanization in the city, as well as the petrochemical and fertilizer industry. The study aimed to achieve a human health risk assessment of urban parks soils, specifically for Cu, Hg, Ni, Pb and Zn. To carry out the risk assessment using the USEPA model, three urban parks with a history of contamination were studied, using different soil exposure pathways (oral, dermal and inhalation) in the carcinogenic (Ni and Pb) and non-carcinogenic (Cu, Hg, Ni, Pb and Zn) scenarios for children and adults. The non-carcinogenic risk of Pb was found in the three urban parks studied, for children and Hg in two urban parks. Pb and Ni showed no carcinogenic risk. Even so, the high non-carcinogenic risk of Hg and Pb showed that the contamination of the past and the present are found in the urban parks of Rio Grande city, putting the health of children who use these collective spaces at risk.

Potentially toxic elements and polycyclic aromatic hydrocarbons in street dust of Yazd, a central capital city in Iran: contamination level, source identification, and ecological-health risk assessment

Contamination level, source, and ecological-health risk of potentially toxic elements (PTEs) and polycyclic aromatic hydrocarbons (PAHs) in the street dust of Yazd, a central capital city in Iran, were investigated for the first time regarding samples collected from 21 sites. Geochemical indices pointed out an enrichment trend of [Formula: see text] and an ecological risk trend of [Formula: see text]. The ecological risk indices of PAHs reflected high ecological risk for pyrene (Pyr). The statistical approach along with the isomeric ratios of PAHs suggested that the traffic-related sources, such as wearing of tires and brake pads, and the vehicular exhaust emissions were greatly responsible for the elevated concentrations of Pb, Cu, Sb, and PAHs, while Al, Ni, Co, V, Mn, As, and, to a lesser extent, Fe, Zn, Mo, and Cr were mainly influenced by geogenic sources. The human health risk assessment of PTEs and PAHs reflected that As, Cr, and Pb pose the highest non-carcinogenic risk in adults and children, compared with other PTEs and also PAHs. The carcinogenic health risk of Pb in the children and PAHs in both subpopulations was high for cancer development.

Occurrence, distribution and human exposure of phthalic esters in road dust samples across China

203 road dust samples were conducted across China covering 28 provinces from January to February，2016 to comprehensively investigates the occurrence, distribution and human exposure of 21 phthalic esters (PAEs). The concentration of Σ₂₁PAEs in road dust ranged from 2.3 to 531 mg/kg, with a mean concentration of 64.1 ± 57.2 mg/kg. DEHP, DnBP and DiBP were the dominant components accounting for 63.3-97.9% (mean: 92.1%) of the Σ₂₁PAEs. Significant Pearson correlation (r = 0.51, p < 0.0001) between Σ₂₁PAEs concentrations and longitude demonstrated a distinguished geographical trend. Higher concentration of PAEs in sidewalk (SW) and trunk road (TR) may reflect influence of human activities such as shoe wear and traffic load. Significant differences were found among different human activities area (urban commercial, urban residential, and suburbs/rural). For total daily intake of Ʃ₂₁PAEs via street dust, children had the highest exposure risk followed by teenagers and adults with the median values of 160.8, 43.6, and 37.7 ng/kg-bw/day, respectively. The maximum exposure risk of PAEs calculated based on measurement and simulation were all far below reference values. The sensitivity analysis results demonstrated that concentrations, ingestion rate (IR) and fraction of PAEs absorbed in the skin (AF) were most important parameters on the assessment of exposure risk of PAEs via street dust. Specific parameters based on China and Chinses population is needed to obtain more reliable exposure risk via street dust.

Elucidating the distribution and sources of street dust bound PAHs in Durgapur, India: A probabilistic health risk assessment study by Monte-Carlo simulation

Spatial and seasonal distribution of PAHs, source identification, and their associated carcinogenic health risk was investigated in street dust of Durgapur, India. Street dust is an important indicator to detect the quality of the environment as well as the sources of pollutants. The obtained results showed fluctuation in PAHs concentrations from 2317 ± 402 ng/g to 5491 ± 2379 ng/g along with the sampling sites. Seasonal variation revealed higher PAHs concentrations in the winter season (5401 ± 993 ng/g) with the maximum presence of 4-ring PAHs. Two-way analysis of variance (ANOVA) exposed that the sites, seasons and site-season interactions were vividly affected by dissimilar PAHs. The PAHs source identification was investigated by principal component analysis (PCA), positive matrix factorization (PMF), diagnostic ratios, and they revealed pyrogenic, diesel, gasoline, wood and coal combustion to be the key sources of the PAHs in street dust. Obtained results from incremental lifetime cancer risk (ILCR) model exhibited the carcinogenic risk for children ranged from 2.4E-06 to 3.8E-06 while 2.1E-06 to 3.4E-06 for adults which were above the baseline value 1.0E-06. The Monte Carlo simulation model identified cumulative cancer risk of sixteen PAHs in 50th percentile were 2.8 and 1.7 times more while in 95th percentile, the values were 8.8 and 7.8 times higher than the acceptable value of 1E-06 for child and adult respectively.

The occurrence and distribution of polycyclic aromatic hydrocarbons, bisphenol A and organophosphate flame retardants in indoor dust and soils from public open spaces: Implications for human exposure

Global concern exists regarding human exposure to organic pollutants derived from public open spaces and indoor dust. This study has evaluated the occurrence of 18 polycyclic aromatic hydrocarbons (PAHs), 11 organophosphorus flame retardants (OPFRs) and bisphenol A (BPA). To achieve this, a new simple, efficient and fast multi-residue analytical method based on a fully automated pressurised liquid extraction (PLE) and subsequent quantification by gas chromatography coupled to electron ionization-mass spectrometry (GC-EI-MS) in selected ion monitoring (SIM) mode was developed. The developed method was applied to indoor dust (12 sampling households) and soil derived from two public open spaces (POSs). Among all compounds studied, PAHs were the most ubiquitous contaminants detected in POS soils and indoor dust although some OPFRs and BPA were detected in lower concentrations. An assessment of the incremental lifetime cancer risk (ILCR) was done and indicated a high potential cancer risk from the POS sites and some of the indoor dust sampled sites. However, key variables, such as the actual exposure duration, frequency of contact and indoor cleaning protocols will significantly reduce the potential risk. Finally, the ingestion of soils and indoor dust contaminated with OPFRs and BPA was investigated and noted in almost all cases to be below the USEPA reference doses.

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 (I_geo) 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.

Organic pollutants in indoor dust from Ecuadorian Amazonia areas affected by oil extractivism

Fifty-five household dust samples collected within six settlements surrounding oil production complexes along the Ecuadorian Amazonia were analysed to evaluate the occurrence and distribution of polycyclic aromatic hydrocarbons (PAHs), phthalates, alkylphenols (APs), bisphenol A (BPA), nicotine, organophosphorus flame retardants (OPFRs), polychlorinated biphenyls (PCBs), legacy organochlorine pesticides (OCs) and organophosphorus pesticides. Studied areas are mainly affected by gas flares emissions and oil spilling coming from extractivist operations and pesticides used in agriculture. Median ΣPAHs values ranged from 739 to 1182 ng g^-1 and up to 52% of the PAH dust concentrations were associated to petrogenic activities from crude oil extraction, according to diagnostic ratios. ΣPAHs and toxic equivalents based on benzo[a]pyrene concentration (ΣTEQ_BaP, ng g^-1) suggested similar toxicities among the different areas. Individual lifetime cancer risk (ILCR_dust) was calculated for ingestion and dermal contact exposure routes and a non-acceptable total carcinogenic risk of up to 10^-4 (one case per ten thousand people) was found for newborns from 0 to 3 years-old in Pimampiro area. Plasticisers and OPFRs were present in dust at maximum median concentrations of 332,507 ng g^-1 (DEHP), 5,249 ng g^-1 (DBP), 1,885 ng g^-1 (BPA), 871 ng g^-1 (TBOEP) and 122 ng g^-1 (TEHP). Some dust samples from Ecuadorian houses had high maximum levels of legacy and modern pesticides such as chlorpyrifos (up to 44,176 ng g^-1), 4,4'-DDT (12,958 ng g^-1), malathion (34,748 ng g^-1) and α+β-endosulfan (10,660 ng g^-1) attributed to inappropriate use and storage of the pesticides. Finally, nicotine was seldom detected (36 ng g^-1). The sources and risks of these compounds are discussed based on the activities carried out in the study areas and attending to an additional non-cancer risk assessment which showed high hazard quotients (HQ) and hazard indexes (HI) for DEHP, DBP, 4,4'-DDT, malathion, chlorpyrifos, naphthalene and benzo[a]pyrene in newborns and children up to 16 years-old.

Nationwide health risk assessment of juvenile exposure to polycyclic aromatic hydrocarbons (PAHs) in the water body of Chinese lakes

The high emissions of polycyclic aromatic hydrocarbons (PAHs) pose a serious threat to the lake ecosystem and human health, and the human health risk assessment of PAH exposure is expected as an urgent project in China. This paper focused on 44 Chinese lakes in 6 lake zones to investigate the occurrence, composition and source of 19 PAHs in water body and estimate the human health risk under PAH exposure. The "List of PAH Priority Lakes" in China was generated based on the combination of incremental lifetime cancer risk (ILCR) model and Monte Carlo simulation. Our results showed that the Σ₁₇ PAHs ranged from 3.75 ng·L^-1 to 368.68 ng·L^-1 with a median of 55.88 ng·L^-1. Low-ring PAHs were the predominant compounds. PAH profiles varied significantly at lake zone level. Diagnostic ratios showed that PAHs might derive from petroleum and coal or biomass combustion. Benzo[a]pyrene-equivalent toxic concentrations (BaPeq) of the Σ₁₇ PAHs ranged from 0.07 ng·L^-1 to 2.26 ng·L^-1 (0.62 ± 0.52 ng·L^-1, mean ± standard deviation) with a median of 0.47 ng·L^-1. Benzo[a]anthracene (BaA), benzo[a]pyrene (BaP) and benzo[e]pyrene (BeP) were the main toxic isomers. Juvenile exposure to PAHs via oral ingestion (drinking) and dermal contact (showering) had negligible and potential health risks, respectively. Juveniles were the sensitive population for PAH exposure. 15 lakes were screened into the "List of PAH Priority Lakes" in three priority levels: first priority (Level A), moderate priority (Level B) and general priority (Level C). Lake Taihu, Lake Chaohu and Lake Hongze were the extreme priority lakes. Optimizing the economic structures and reducing the combustion emissions in these areas should be implemented to reduce the population under potential health risk of PAHs.

Characterization of the pollutant build-up processes and concentration/mass load in road deposited sediments over a long dry period

Trace metals and nutrients attached on road deposited sediments (RDS) are the main source of non-point pollution to urban waterbodies causing ecological degradation and eutrophication problems. Mathematical models of the pollutant build-up process on road surfaces can be used to develop remediation measures. However, there was lack of research on the pollutant build-up process of various sized particles during a long dry period. This research investigated the build-up behaviors of specific pollutants in size-fractioned particles during 41 antecedent dry-weather days (ADDs), which was the longest build-up period ever studied. This research revealed that the pollution concentration exhibited a mono-growth behavior, while the pollutant mass followed a cyclic behavior during the study period. The time to peak and the build-up cycle of various pollutant mass were all highly associated with the particle characteristics, and the mass and concentration levels of pollutants in various sized particles were different. Furthermore, two important phenomena were found in this study: the bioavailability of phosphorus as well as the enrichment factors of metals all increased along with time during the build-up process. These findings provide new insights in non-point source pollution build-up and improve the water quality modelling.

Contamination and cancer risk assessment of polycyclic aromatic hydrocarbons (PAHs) in urban dust from different land-uses in the most populated city of Iran

Due to population growth and the considerable increase in usage of the resources, Human environment quality has been highly threatened by pollutants in recent decades. Polycyclic aromatic hydrocarbons (PAHs) are widespread, persistent organic pollutants which are of great concern due to their carcinogenicity. The present study is the first investigation that assesses contamination, sources and cancer risk of 16 priority PAHs proposed by US EPA in urban dust samples (n = 80) taken in different land-uses of Tehran metropolis, the capital of Iran. Gas chromatography-mass spectrometry (GC-MS) is used to measure PAHs concentrations. The results showed that the average concentration of the total 16 PAHs and the average Benzo[a]pyrene total potency equivalency were 566 μg kg^-1 dry weight and 36.4 μg kg^-1, respectively. In the commercial and residential land-uses high molecular weight (HMW) PAHs were dominated, whereas in green lands, light molecular weight (LMW) PAHs showed maximum contribution. The highest concentration of total PAHs were observed in the commercial areas due to limited air circulation and heavy traffic loads. Incremental Lifetime Cancer Risk (ILCR) model was applied to evaluate the cancer risk of exposure to PAHs contaminated dust. Based on the results, Tehran's residents (children and adults) in various land-uses except for green lands, are in high potential cancer risk of PAHs via ingestion and dermal contact exposure routs. Ace, Chr, Pyr, and BghiP which are indicators of traffic emissions, were found to be predominant PAH contributors in urban dust of commercial areas. Also, Ace, Fl, Phe, and BghiP which are derived from fossil fuel combustion, were mainly observed in the industrial land-use. Based on the results of factor analysis and diagnostic ratios, Diesel/gasoline engine vehicular emissions and combustion were found to be the main sources of PAHs in urban dust of Tehran.

Levels, spatial distribution, risk assessment, and sources of environmental contamination vectored by road dust in Cienfuegos (Cuba) revealed by chemical and C and N stable isotope compositions

Road dust is an indicator widely used when monitoring contamination and evaluating environmental and health risks in urban ecosystems. We conducted an exhaustive characterization of road dust samples coupling their chemical characteristics and stable isotope compositions (C and N) with the aim of evaluating the levels and spatial distribution of local contamination as well as to identify its main source(s) in the coastal city of Cienfuegos (Cuba). Results indicate that the concentrations of several elements (total nitrogen, S, Ca, V, Cu, Zn, Mo, Sn, Hg, and Pb) exceed the background values reported for both Cuban soils and the upper continental crust (UCC) and showed a high variability among the sampling sites. We show that road dust contamination in Cienfuegos induces high associated ecological risks. Among the studied elements, Cd and Hg are the major contributors to the environmental contamination in the city, mainly along busy roads and downtown. δ¹³C and δ¹⁵N, coupled to a multivariate statistical analysis, help associate the studied elements to several local sources of contamination: mineral matter derived from local soils, cement plant and related activities, road pavement alteration, power plant, road traffic, and resuspension of particulate organic matter (POM). Our results suggest that incorporating the chemical and isotope monitoring of road dust may help implement more effective environmental management measures in order to reduce their adverse impact on ecosystems and human health.

Characteristics and health risk assessment of polycyclic aromatic hydrocarbons associated with dust in household evaporative coolers

This study reports a characterization of indoor polycyclic aromatic hydrocarbons (PAHs) associated with dust (dust-PAHs) in household evaporative coolers and their associated health effects. Extensive analysis showed that the indoor dust-PAHs stemmed mostly from pyrogenic sources (vehicular emissions) with mean total concentrations limited between 131 and 429 ng g^-1. The distribution pattern of PAHs based on number of rings exhibited the following order of decreasing relative abundance: 4 > 3 > 5 > 6 > 2 rings. Results indicate that the mutagenicity of dust-PAHs exceeded their carcinogenicity, but that the potential carcinogenic effects are still significant. The mean lifetime cancer risk for different age groups for three pathways based on Model 2 (dermal (1.39 × 10^-1 to 1.91 × 10^-2), ingestion (2.13 × 10^-3 to 8.08 × 10^-3) and inhalation (1.62 × 10^-7 to 4.06 × 10^-7)) was 7.4-146 times higher than values predicted by Model 1 (dermal (5.13 × 10^-5 to 3.03 × 10^-3), ingestion (9.34 × 10^-5 to 1.31 × 10^-3) and inhalation (7.13 × 10^-20 to 1.68 × 10^-20)). Hence, exposure to dust-PAHs in household evaporative coolers lead to high risk, especially for children (less than 11 years) (HQ = 2.71 × 10^-20 to 54.8 and LTCRs = 7.13 × 10^-20 to 1.39 × 10^-1). Strategies should be considered to eliminate such pollutants to protect people, especially children, from the non-carcinogenic and carcinogenic effects by changing household evaporative coolers with other cooling systems.

Road dust contamination by polycyclic aromatic hydrocarbons and their methylated derivatives in northern Vietnam: Concentrations, profiles, emission sources, and risk assessment

Concentrations of unsubstituted and methylated polycyclic aromatic hydrocarbons (PAHs and Me-PAHs) were examined in road dusts from some representative areas with different land-use types in northern Vietnam, providing updated information about the occurrence, sources, and risks of these pollutants in Southeast Asian region. The Vietnamese road dusts were contaminated with low to moderate levels of PAHs and Me-PAHs as compared to those from other countries in the world. Concentrations of PAHs and Me-PAHs (Σ34PAHs) decreased in the order: urban (median 1800; range 1100-5500) ≈ industrial (1300; 550-10,000) > suburban (450; 310-1300) ≈ rural road dust (330; 210-2300 ng g^-1), suggesting an urban-rural declining trend and effects of urbanization-industrialization processes in PAH emission extent in Vietnam. The profiles and diagnostic ratios of PAHs and Me-PAHs in our samples revealed that these compounds were mainly derived from pyrogenic sources rather than petrogenic sources. Traffic emissions (e.g., vehicle exhaust, tire debris, and possible leaks of fuels, oils, and lubricants) were estimated as principal sources of PAHs and Me-PAHs, especially in the urban and industrial areas. Other pyrogenic sources (e.g., coal, wood, and biomass combustion) were also existed in the industrial, suburban, and rural areas, reflecting PAH origins from thermal industrial processes, open burning of agricultural by-products, and domestic energy utilization. Persons working outdoors and children in the urban and industrial areas were estimated to receive higher intake doses of PAHs and Me-PAHs, which were one to two orders of magnitude higher than those estimated for other groups. Except for potential cancer risk estimated for the occupational groups in the industrial area under the worst exposure scenarios, the non-cancer and cancer risk levels were generally acceptable; however, more comprehensive risk assessment considering other exposure pathways (e.g., inhalation and diet) is needed.

Occurrence of heavy elements in street dust from sub/urban zone of Tianjin: pollution characteristics and health risk assessment

Main purpose of this study was to determine the concentrations of selected heavy elements (As, Cd, Pb, Cu, Co, Cr and Ni) in the street dust samples (n = 49) collected from seven districts located in suburban/urban zone of Tianjin in order to estimate their possible sources and degree of environmental pollution as well as human health risk. Mean concentrations (mg kg^-1) of As (19.3), Cd (0.60), Pb (28.4) and Cu (62.7) were above their corresponding soil background values. According to the results of multivariate statistical analysis, the accumulation of As, Cd, Pb, Cu and Cr in street dust was affected by anthropogenic activities, while the contents of Ni and Co were associated with natural sources. Pollution degree by geo-accumulation index had the following trend: Cd > Cu > As > Pb > Cr > Ni > Co. Dust contamination with Cd ranged from unpolluted to highly polluted. Potential ecological risk indicated low (Pb, Cu, Cr, Co and Ni) to high (Cd) risk, while potential risk index showed moderate and very high risks. Non-carcinogenic risk of the studied elements was below safe level (<1). Data obtained in this investigation gave the additional values to the knowledge needed for future monitoring and risk assessment, relating the presence of heavy elements studied in suburban/urban areas.

Source identification of total petroleum hydrocarbons and polycyclic aromatic hydrocarbons in PM10 and street dust of a hot spot for petrochemical production: Asaluyeh County, Iran

Total petroleum hydrocarbons (TPH) and polycyclic aromatic hydrocarbons (PAHs) are important pollutants that affect public health in urban areas, especially in developing and oil-rich countries such as Iran. This assesses the relationship between TPH and PAHs in street dust and suspended dust, and investigates toxicity level in the urban environment of the most important petrochemical center in Iran. For this purpose, 21 and 48 street dust samples were collected for TPH analysis and PAH analysis, respectively, in Asaluyeh County. Moreover, seven air dust samples were taken for PAH analysis. TPH concentrations ranged between 240 and 4400 mg kg-1, with a mean of 1371.43 mg kg-1. The maximum ∑PAH concentration (6016.3 mg kg-1) was detected in a petrochemical complex while the minimum ∑PAHs content (16.93 mg kg-1) was measured in an urban area. The mean concentrations of total PAHs in street dust particles were 491.35 mg kg-1 in summer and 304.04 mg kg-1 in winter. The results indicated that PAH concentration in summer was higher. PAH sources were identified using both PAHs ratios and robust statistical methods such as Generalized Estimating Equations (GEE), backward GEE, logistic regression, principal components analysis (PCA) in conjunction with multiple linear regression (MLR) and positive matrix factorization (PMF). The results showed that PAH species generally originate from pyrogenic sources and about 0.08% of TPH was typically PAHs. However, petrogenic sources of PAHs in the industrial areas were 11.2 times more abundant than in urban areas. Also, backward GEE model demonstrated that TPH is more influenced by HMW PAHs, particularly indene. Estimated incremental lifetime cancer risk (ILCR) was higher than 10-4, showing that Asaluyeh inhabitants (especially children and indoor workers) are probably exposed to cancer risk, particularly through dermal contact and dust ingestion.

Street Dust-Bound Polycyclic Aromatic Hydrocarbons in a Saudi Coastal City: Status, Profile, Sources, and Human Health Risk Assessment

Polycyclic aromatic hydrocarbons (PAHs) in street dust pose a serious problem threatening both the environment and human health. Street dust samples were collected from five different land use patterns (traffic areas TRA, urban area URA, residential areas REA, mixed residential commercial areas MCRA and suburban areas SUA) in Jeddah, a Saudi coastal city, and one in in Hada Al Sham, a rural area (RUA). This study aimed to investigate the status, profile, sources of PAHs and estimate their human health risk. The results revealed an average concentration of total PAHs of 3320 ng/g in street dust of Jeddah and 223 ng/g in RUA dust. PAHs with high molecular weight represented 83.38% of total PAHs in street dust of Jeddah, while the carcinogenic PAH compounds accounted 57.84%. The highest average concentration of total PAHs in street dust of Jeddah was found in TRA (4980 ng/g) and the lowest in REA (1660 ng/g). PAHs ratios indicated that the principal source of PAHs in street dust of Jeddah is pyrogenic, mainly traffic emission. Benzo(a)anthracene/chrysene (BaA/CHR) ratio suggests that PAHs in street dusts of Jeddah come mainly from emission of local sources, while PAHs in RUA might be transported from the surrounding urban areas. The estimated Incremental Lifetime Cancer Risk (ILCR) associated with exposure to PAHs in street dusts indicated that both dermal contact and ingestion pathways are major contributed to cancer risk for both children and adults. Based on BaPequivalence concentrations of total PAHs, ILCRIngestion, ILCRdermal and cancer risk values for children and adults exposed to PAHs in street dust of different areas in Jeddah were found between 10-6 and 10-4, indicating potential risk. The sequence of cancer risk was TRA > URA > MCRA > SUA > REA. Only exposure to BaP and DBA compounds had potential risk for both children and adults.