Polycyclic aromatic hydrocarbons in fine road dust from a coal-utilization city: Spatial distribution, source diagnosis and risk assessment

The effect of polycyclic aromatic hydrocarbon biomarkers on cardiovascular diseases

Polycyclic aromatic hydrocarbon (PAHs) are part of particulate matter (PM), which is produced from incomplete combustion of organic matter. Biomarkers mean biological indicators, molecules that indicate a normal or abnormal process in the body and may be a sign of a condition or disease. Studies show that PAHs increase the risk of cardiovascular diseases through processes such as oxidative stress, inflammation and atherosclerosis. The present study focused on the evaluation of health effects PAHs biomarkers on cardiovascular diseases (CVD). In this narrative study, data were collected from databases such as Scopus, PubMed, Web of science and Google Scholar in the period 1975-2023. After screening, duplicate and irrelevant articles were removed. Finally, 68 articles related to the effect of PAHs on CVD were included in the study. In addition to the articles found through the search in databases, another 18 articles from the references of the selected articles were included. According to the finding in during the biotransformation of PAH, a number of metabolites are made, such as phenols, diols, quinones, and epoxides. Phenolic isomers have the highest percentage and biomarkers used for their detection include 2-OHNAP used to trace naphthalene from heating processed food, 3-OHPHEN used to trace phenanthrene from diesel, 2-OHFLU used to trace fluorene and 1-OHPYR used to trace pyrene from cigarette and hookah smoke. According to the result, increasing blood pressure and heart rate and causing atherosclerosis are the main complications due to exposure to PAH metabolite on cardiovascular system. The most important agents that causes this affects including increased homocysteine, cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), serum biomarkers of C-reactive protein, and triglycerides. Result this study showed that cardiovascular diseases risk is increased by exposure to PAH biomarkers from smoking, car emissions, occupational exposure, and incinerators. Therefore, strict controls should be implemented for sources of PAH production and exposure.

Application of tree cores to investigate the historical pollution trends of atmospheric polycyclic aromatic compounds: A case study in a typical coal-contaminated region of China

In this study, 76 polycyclic aromatic compounds (PACs) were detected in air, soil, and tree core samples from Huainan, a typical coal-contaminated region of China. Concentrations of ΣPACs in soil and air samples were 2400 ± 5100 ng/g and 150 ± 63 ng/m3, respectively. Priority PAHs were predominant in both air and soil samples, contributing over 50 % of ΣPACs. Source analysis indicated that PAC contamination in Huainan primarily originated from local coal-related activities. The benzo[a]pyrene (BaP)-toxic equivalent concentrations (TEQBaP) of PACs in the air samples (5.6 ± 5.3 ng/m3) exceeded the threshold of 1 ng/m3. Some PACs, such as benzo[e]pyrene (BeP) and Alk-BaPs, demonstrated significant toxicity and are recommended for consideration as priority pollutants. The historical pollution trends of atmospheric PACs were obtained based on the tree core samples. PAC concentrations in tree core segments showed a strong correlation with atmospheric PM10 levels in Huainan. As air quality has improved in recent years, the PACs concentrations in tree core segments have also decreased. Historical fluctuations of atmospheric PACs were largely attributed to the changes in the gas treatment systems of a nearby coal-fired power plant and adjustments in environmental policies. By integrating trends observed in tree core segments with air concentrations, the historical atmospheric PAC concentrations were extrapolated. The extrapolated results showed similar concentration levels and trends when compared with historical data from other studies in China. Thus, tree cores can not only reflect the historical trends of atmospheric PACs with high temporal precision but also are feasible for extrapolating historical concentrations of airborne PACs.

Understanding polycyclic aromatic hydrocarbon accumulation in road dust of a tropical megacity in southern Vietnam: Implications on environmental management

This study investigated the characteristics of 23 PAHs in road dust from various areas in Ho Chi Minh City (HCMC), focusing on spatial distribution, pollution levels, human health risks, and source apportionment. PAH levels in urban samples (residential and industrial sites) ranged from 208 to 7665 (μg/kg), significantly higher than background levels (135 ± 42.2 μg/kg). A west > east gradient in PAH distribution, particularly in crowded traffic intersections, suggested traffic activities as a major source. Pollution load indices indicated moderate to very high pollution in most urban sites. Incremental lifetime cancer risk assessments showed moderate to high risks, especially for children. Statistical analyses and diagnostic ratios identified vehicular emissions as the primary PAH sources, with Positive Matrix Factorization analysis attributing 46.6% to gasoline vehicles, 21.9% to diesel vehicles and petroleum evaporation, 18.3% to tar oil, and 10.2% to coal burning. This study fills a significant information gap on PAHs in road dust, which has not been previously reported in southern Vietnam, specifically in HCMC-a dynamic and rapidly developing city in Southeast Asia. The findings highlight the need for synchronized management and technical solutions to mitigate PAH risks in road dust, contributing valuable knowledge on PAH accumulation in a major southern city of Vietnam.

Distribution, sources, and risk assessment of polycyclic aromatic hydrocarbons in surface soils and plants from industrial and agricultural areas, Junggar Basin, Xinjiang

The contamination characteristics of Polycyclic Aromatic Hydrocarbons (PAHs) in different environmental functional areas are different. In this study, the contamination of PAHs in soils and common plants in typical mining and farmland areas in Xinjiang, China, was analyzed. The results showed that the contamination levels of PAHs in mining soils were significantly higher than those in farmland soils, and the mining soils were dominated by 4-5-ring PAHs and farmland soils by 3-4-ring PAHs. Analysis of their sources using a positive definite factor matrix model showed that PAHs in mining soils mainly originated from coal and natural gas combustion, and transportation processes; while farmland soils mainly came from biomass and coal combustion, and fossil fuel volatile spills. The cancer risk of PAHs in soils was evaluated using a combination of the Monte Carlo and the lifetime carcinogenic risk models, and the results showed that the overall level of cancer risk for mining soils was higher than that for farmland soils, and can put some people in high risk of cancer. For plant samples, except for individual crop samples, the contamination levels of mining plants and crops were similar, with 4-5-ring PAHs dominating in desert plants in mining areas and the highest proportion of 3-ring PAHs in crops in agricultural fields, and PAHs in both plants were mainly from biomass and coal combustion. The results of correlation analysis showed that 2-ring PAHs in crop roots were significantly positively correlated with it in corresponding soils, and some high-ring PAHs in crop leaves were significantly negatively correlated with it in corresponding soils. Therefore, there were significant differences in the pollution characteristics of PAHs in soils and common plants in mining and agricultural areas. Human health risks and ecological risks are mainly concentrated in mining areas, and appropriate intervention measures should be taken for pollution remediation.

Source-specific probabilistic health risk assessment of dust PAHs in urban parks based on positive matrix factorization and Monte Carlo simulation

Understanding the health risks of polycyclic aromatic hydrocarbons (PAHs) in dust from city parks and prioritizing sources for control are essential for public health and pollution management. The combination of Source-specific and Monte Carlo not only reduces management costs, but also improves the accuracy of assessments. To evaluate the sources of PAHs in urban park dust and the possible health risks caused by different sources, dust samples from 13 popular parks in Kaifeng City were analyzed for PAHs using gas chromatograph-mass spectrometer (GC-MS). The results showed that the surface dust PAH content in the study area ranged from 332.34 µg·kg-1 to 7823.03 µg·kg-1, with a mean value of 1756.59 µg·kg-1. Nemerow Composite Pollution Index in the study area ranged from 0.32 to 14.41, with a mean of 2.24, indicating that the overall pollution warrants attention. Four pollution sources were identified using the positive matrix factorization (PMF) model: transportation source, transportation-coal and biomass combustion source, coke oven emission source, and petroleum source, with contributions of 33.74%, 25.59%, 22.14%, and 18.54%, respectively. The Monte Carlo cancer risk simulation results indicated that park dust PAHs pose a potential cancer risk to all three populations (children, adult male and adult female). Additionally, the cancer risk for children was generally higher than that for adult males and females, with transportation sources being the main contributor to the carcinogenic risk. Lastly, sensitivity analyses results showed that the toxic equivalent concentration (CS) is the parameter contributing the most to carcinogenic risk, followed by Exposure duration (ED).

A 6-year review status on soil pollution in coal mining areas from Europe

Coal is an essential component in achieving the goal of fulfilling the energy demands of the world. Nevertheless, the extensive practice of coal mining has resulted in environmental contamination through the release of both organic and inorganic pollutants, including polycyclic aromatic compounds and potentially toxic elements, into various mediums, notably soil. The escalating coal-mining activities across Europe have amplified the concentration of specific elements in the soil. Therefore, a thorough and meticulous assessment of these environmental impacts is imperative to furnish policymakers, industries, and communities with valuable insights, facilitating the formulation and adoption of effective mitigation strategies. Considering the results of studies from 2018 to 2023, this review thoroughly evaluates the current state of soil pollution in the coal mining areas of Europe, focusing on polycyclic aromatic hydrocarbons and potentially toxic elements. By analyzing the acquired data, this study aims to evaluate the levels of contamination by these pollutants in soils. The findings reveal that low molecular weight polycyclic aromatic hydrocarbons dominate the polycyclic aromatic compounds present, while potentially toxic elements including Zn, Pb, Mn, and Cr emerge as major contributors to soil contamination in coal mining areas from Europe.

Simulation and parameter determination of the net sorption of phenanthrene by sediment particles

The distribution of polycyclic aromatic hydrocarbons (PAHs) in the ocean is affected by the sorption-desorption process of sediment particles. This process is determined by the concentration of PAHs in seawater, water temperature, and organic matter content of sediment particles. Quantitative relationships between the net sorption rates (=the difference of sorption and desorption rates) and these factors have not been established yet and used in PAH transport models. In this study, phenanthrene was chosen as the representative of PAHs. Three groups of experimental data were collected to address the dependence of the net sorption processes on the initial concentration, water temperature, and organic carbon content representing organic matter content. One-site and two-compartment mass-transfer models were tested to represent the experimental data using various parameters. The results showed that the two-compartment mass-transfer model performed better than the one-site mass-transfer model. The parameters of the two-compartment mass-transfer model include the sorption rate coefficients kafand kas (L g-1 min-1), and the desorption rate coefficients kdf and kds (min-1). The parameters at different temperatures and organic carbon contents were obtained by numerical simulations. Linear relationships were obtained between the parameters and water temperature, as well as organic carbon content. kaf, kas and kdf decreased linearly, while kds increased linearly with temperature. kaf, kas and kdf increased linearly, while kds decreased linearly with organic carbon content. The r2 values between the simulation results based on the relationships and the experimental results reached 0.96-0.99, which supports the application of the model to simulate sorption-desorption processes at different water temperatures and organic carbon contents in a realistic ocean.

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

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

Distribution, sources, and risk assessment of polycyclic aromatic hydrocarbons (PAHs) in Kaokaowusu river sediments near a coal industrial zone

This study systematically analyzed the contents, compositions, and sources of polycyclic aromatic hydrocarbons (PAHs) in river sediments near an important energy and chemical base in northwest China. In addition, their possible adverse effects on the ecology and human health were assessed. The PAH concentrations in this study area ranged from 2641.28 to 16783.72 (ng/g dw). PAHs of medium molecular weight (3-ring and 4-ring) showed the largest proportion, followed by PAHs of higher molecular weight (5-ring and 6-ring). The results of molecular diagnostic ratios and principal component analysis revealed that PAHs in the region have complex sources, with incomplete combustion of local fossil fuels and traffic exhaust factors being the main sources. The total toxic equivalent concentration of PAHs varied from 10.05 to 760.26 ng/g, and according to the sediment quality guidelines, PAHs have high potential ecological risk in the lower reaches of the river. The mean effect range-median quotient for the region was 0.46, and the combined ecological risk was at moderate to high levels (21% probability of toxicity). The lifetime carcinogenic risks for adults and children exposed to PAHs were 2.95 × 10-3 and 1.87 × 10-2, respectively, which are much higher than the limit of 10-4, indicating moderate to high potential cancer risks. Therefore, the local government should consider taking some environmental remediation measures. This study can provide theoretical support for pollution prevention measures and ecological restoration strategies for rivers in resource-rich areas.

Comparative 6+studies of environmentally persistent free radicals on nano-sized coal dusts

Coal dust is the major hazardous pollutant in the coal mining environment. Recently environmentally persistent free radicals (EPFRs) were identified as one of the key characteristics which could impart toxicity to the particulates released into the environment. The present study used Electron Paramagnetic Resonance (EPR) spectroscopy to analyze the characteristics of EPFRs present in different types of nano-size coal dust. Further, it analyzed the stability of the free radicals in the respirable nano-size coal dust and compared their characteristics in terms of EPR parameters (spin counts and g-values). It was found that free radicals in coal are remarkably stable (can remain intact for several months). Also, Most of the EPFRs in the coal dust particles are either oxygenated carbon centered or a mixture of carbon and oxygen-centered free radicals. EPFRs concentration in the coal dust was found to be proportional to the carbon content of coal. The characteristic g-values were found to be inversely related to the carbon content of coal dust. The spin concentrations in the lignite coal dust were between 3.819 and 7.089 μmol/g, whereas the g-values ranged from 2.00352 to 2.00363. The spin concentrations in the bituminous coal dust were between 11.614 and 25.562 μmol/g, whereas the g-values ranged from 2.00295 to 2.00319. The characteristics of EPFRs present in coal dust identified by this study are similar to the EPFRs, which were found in other environmental pollutants such as combustion-generated particulates, PM_2.5, indoor dust, wildfires, biochar, haze etc., in some of the previous studies. Considering the toxicity analysis of environmental particulates containing EPFRs similar to those identified in the present study, it can be confidently hypothesized that the EPFRs in the coal dust might play a major role in modulating the coal dust toxicity. Hence, it is recommended that future studies should analyze the role of EPFR-loaded coal dust in mediating the inhalation toxicity of coal dust.

Biomonitoring of polycyclic aromatic hydrocarbons, heavy metals, and plasticizers residues: role of bees and honey as bioindicators of environmental contamination

Polycyclic aromatic hydrocarbons (PAHs), heavy metals, and plasticizer residues are continuously released into the environment. The use of living organisms, such as Apis mellifera L. and honey, is advantageous as bioindicator of the environmental health status, instead of traditional monitoring methods, showing the ability to record spatial and temporal pollutant variations. The PAHs and heavy metal presence were determined in two sampling years (2017 and 2018) in five different locations in the Molise region (Italy), characterized by different pollution levels. During 2017, most PAHs in all samples were lower than limit of detection (LOD), while in 2018, their mean concentration in bee and honey samples was of 3 μg kg^-1 and 35 μg kg^-1, respectively. For heavy metals, lower values were detected in 2017 (Be, Cd, and V below LOD), while in 2018, the mean concentrations were higher, 138 μg kg^-1 and 69 μg kg^-1, in bees and honey, respectively. Honey has been used as indicator of the presence of phthalate esters and bisphenol A in the environment. The satisfactory results confirmed that both bees and honey are an important tool for environmental monitoring. The chemometric analysis highlighted the differences in terms of pollutant concentration and variability in the different areas, validating the suitability of these matrices as bioindicators.