Polycyclic aromatic hydrocarbons in coarse particles (PM10) over the coastal urban region in Poland: Distribution, source analysis and human health risk implications

Current levels, sources, and risks of human exposure to PAHs, PBDEs and PCBs in South American outdoor air: A critical review

This study provides a comprehensive overview of the current levels, sources and human exposure risks to hazardous polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs), and polychlorinated biphenyls (PCBs) in South American outdoor air. Research documents were obtainable for only 6 countries within the target period (2014-2024). For all contaminants, urban concentrations exceeded that of rural/remote locations. PAHs were extensively reported with concentration reaching 1100 ∑16PAHs/m3 in Southwest of Buenos Aires province, Argentina. The health risk data also exceeded the threshold level in several locations. The profiles and seasonal fluctuations across all studies were widely influenced by the prevalent local/domestic sources. Biomass combustion (particularly of sugar cane/agricultural wastes and wood/coal for residential heating), vehicular emission, and industrial emission were accounted for most PAH sources. Regulations targeting biomass combustion for improved air quality seem not to currently have significant impacts on current PAH levels. PBDEs were widely reported within 0.3-55 pg ∑4-14BDE/m3, albeit high concentrations were documented in Concepción Bay, Chile (maximum = 1100 pg ∑4BDE/m3) and Córdoba, Argentina (maximum = 120 pg ∑4BDE/m3). Most notable source of PBDEs is solid municipal wastes. Similar to other global studies, BDE-47, 99 and 209 dominated the congeners reported. PCBs were reported with the highest concentrations measured in Córdoba, Argentina (maximum = 1700 pg ∑30PCBs/m3), but data remain limited in other important locations such as São Paulo, Brazil. Sources of PCBs were broadly associated with solid wastes, electric transformers, and re-volatilization from polluted environment. PAHs, PCBs and PBDEs were all within average to top global concentrations. This study underscores potential rise in atmospheric level of the target contaminants without sustainable regulatory structure and the need for continuous monitoring of these contaminants as a measure of policy impacts. We provide sustainable recommendations.

Chemical investigation of polycyclic aromatic hydrocarbon sources in an urban area with complex air quality challenges

Polycyclic aromatic hydrocarbons (PAHs) are hazardous air pollutants with well-documented carcinogenic, mutagenic, and toxic effects. This study investigates the chemical composition and sources of PAHs in Kraków, a city characterized by diverse air quality challenges. PM10 and PM2.5 samples were collected during the winter seasons of 2014 and 2015, enabling a detailed assessment of PAH concentrations and their atmospheric transformations. The results indicate that PAH levels frequently exceeded European Union and World Health Organization limits, with benzo[a]pyrene (BaP) reaching peak concentrations of 38.8 ng m-3 in PM10 and 30.2 ng m-3 in PM2.5, highlighting significant health risks. To determine PAH sources, a chemical-based framework integrating diagnostic ratios, receptor modeling, and backward trajectory analysis was applied. The findings reveal that coal and biomass combustion were dominant PAH contributors, with additional influences from vehicular emissions and industrial activities. The BaP/(BaP + BeP) ratio suggested that PAHs in PM2.5 underwent more atmospheric aging than those in PM10, indicating that finer particles play a crucial role in PAH transport and transformation. Furthermore, correlations with inorganic and organic PM constituents, such as chloride and levoglucosan, underscored the mixed influence of fossil fuel and biomass burning. The study also evaluated the toxicological implications of PAHs, demonstrating that mutagenic activity exceeded toxicity levels, and finer particles posed a greater carcinogenic risk. While the exposure index suggested that short-term exposure remained within acceptable limits, long-term effects require further assessment. Given the complex interplay of emission sources and atmospheric processes, continuous monitoring and targeted mitigation strategies are essential for improving urban air quality.

Biocatalytic Potential of Pseudomonas Species in the Degradation of Polycyclic Aromatic Hydrocarbons

Polycyclic aromatic hydrocarbons (PAHs), one of the major environmental pollutants, produced from incomplete combustion of materials like coal, oil, gas, wood, and charbroiled meat, that contaminate the air, soil, and water, necessitating urgent remediation. Understanding the metabolic pathways for PAHs degradation is crucial to preventing environmental damage and health issues. Biological methods are gaining increasing interest due to their cost-effectiveness and environmental friendliness. These methods are particularly suitable for remediating PAHs contamination and mitigating associated risks. The paper also outlines the processes for biodegrading PAHs, emphasizing the function of Pseudomonas spp., a kind of bacterium recognized for its capacity to degrade PAHs. To eliminate PAHs from the environment and reduce threats to human health and the environment, Pseudomonas spp. is essential. Understanding the mechanism of PAH breakdown by means of microbes could lead to effective clean-up strategies. The review highlights the enzymatic capabilities, adaptability, and genetic versatility of the genes like nah and phn of Pseudomonas spp., which are involved in PAHs degradation pathways. Scientific evidence supports using Pseudomonas spp. as biocatalysts for PAHs clean-up, offering cost-effective and eco-friendly solutions.

Seasonality, sources apportionment, human health risks assessments, and potential implications on the atmospheric chemistry of polycyclic aromatic hydrocarbons in size-segregated aerosols from a Romanian metropolitan area

Urbanization and industrialization are important transformations shaping the current statement of the society, enhancing significantly the combustion emissions which are threatening the global climate system, air quality, and human health. These emissions contain polycyclic aromatic hydrocarbons (PAHs) which are well known for their high toxicity. The present study is the first assessing the seasonal variation of 17 PAHs in size segregated fractions of atmospheric aerosol particles from a Romanian metropolitan area. In addition to sources apportionment and health risks, the potential role of PAHs on the atmospheric chemistry in the area was also addressed. Higher PAHs concentrations were determined in winter season, the highest values being quantified for benzo[b]fluoranthene, benzo[a]pyrene, and indeno[1,2,3-cd]pyrene. Each analyzed PAH exhibited a dominant peak in the accumulation mode (0.1-1.0 μm), with maxima at 381 nm. Gasoline combustion was identified as a significant contributor to the PAHs levels in the atmospheric aerosols from the area. Biomass-burning contributions were highlighted during the winter and autumn seasons. The positive matrix factorization (PMF) model apportioned four PAHs sources, as follows: vehicular (31%), mixed combustion (33%), biomass and wood burning (19%), and coal and natural gas combustion (18%) sources. Concentration-weighted trajectory (CWT) analysis method revealed clear contributions to PAHs abundances from local and regional air masses. Alveolar region of adults seems to have the highest susceptibility for PAHs deposition. Values exceeding acceptable limits for carcinogenic risk throughout the year are associated with benzo[a]pyrene, benzo[b]fluoranthene, indeno[1,2,3-cd]pyrene, benzo[a]anthracene etc. The present study can be considered as a reference in the region in order measures of mitigation and control for PAHs emission sources to be introduced.

Biomonitoring of polycyclic aromatic hydrocarbons in Brazilian pregnant women: Urinary levels and health risk assessment

Over the years, humans have been continuously exposed to several compounds directly generated by industrial processes and/or present in consumed products. Polycyclic aromatic hydrocarbons (PAHs) are legacy pollutants ubiquitous in the environment and represent the main chemical pollutants in urban areas. Worldwide, studies that aim to understand the impacts of exposure to these chemicals have gained increasing prominence due to their potential toxicity profile, mainly concerning genotoxicity and carcinogenicity. Human biomonitoring (HB) is an analytical approach to monitoring population exposure to chemicals; however, these studies are still limited in Brazil. Thus, this work aimed to evaluate the exposure of Brazilian pregnant women to PAHs through HB studies. Besides, the risk characterization of this exposure was performed. For this purpose, urine samples from 358 Brazilian pregnant women were used to evaluate 11 hydroxylated metabolites of PAHs employing gas chromatography coupled to mass spectrometry. The 1OH-naphthol and 2OH-naphthol were detected in 100% of the samples and showed high levels, corresponding to 16.99 and 3.62 μg/g of creatinine, respectively. 2OH-fluorene (8.12 μg/g of creatinine) and 9OH-fluorene (1.26 μg/g of creatinine) were detected in 91% and 66% of the samples, respectively. Benzo(a)pyrene (BaP) metabolites were detected in more than 50% of the samples (0.58-1.26 μg/g of creatinine). A hazard index of 1.4 and a carcinogenic risk above 10-4 were found for BaP metabolites in the risk characterization. Therefore, our findings may indicate that exposure to PAHs poses a potential risk to pregnant women's health and a high probability of carcinogenic risk due to their exposure to BaP. Finally, this work shows the need for more in-depth studies to determine the sources of exposure and the implementation of health protection measures regarding the exposure of the Brazilian population to PAHs.

Potential of Coupling Metaheuristics-Optimized-XGBoost and SHAP in Revealing PAHs Environmental Fate

Polycyclic aromatic hydrocarbons (PAHs) refer to a group of several hundred compounds, among which 16 are identified as priority pollutants, due to their adverse health effects, frequency of occurrence, and potential for human exposure. This study is focused on benzo(a)pyrene, being considered an indicator of exposure to a PAH carcinogenic mixture. For this purpose, we have applied the XGBoost model to a two-year database of pollutant concentrations and meteorological parameters, with the aim to identify the factors which were mostly associated with the observed benzo(a)pyrene concentrations and to describe types of environments that supported the interactions between benzo(a)pyrene and other polluting species. The pollutant data were collected at the energy industry center in Serbia, in the vicinity of coal mining areas and power stations, where the observed benzo(a)pyrene maximum concentration for a study period reached 43.7 ngm-3. The metaheuristics algorithm has been used to optimize the XGBoost hyperparameters, and the results have been compared to the results of XGBoost models tuned by eight other cutting-edge metaheuristics algorithms. The best-produced model was later on interpreted by applying Shapley Additive exPlanations (SHAP). As indicated by mean absolute SHAP values, the temperature at the surface, arsenic, PM10, and total nitrogen oxide (NOx) concentrations appear to be the major factors affecting benzo(a)pyrene concentrations and its environmental fate.

Carcinogenic Activity and Risk Assessment of PAHs in Ambient Air: PM10 Particle Fraction and Bulk Deposition

This paper present seasonal variation in the equivalent concentration (BaP_eq) of PAHs in order to assess the potential cancer risk for two different groups of residents via ingestion, dermal contact and inhalation pathways. The possible ecological risk caused by PAH atmospheric deposition based on risk quotient was also estimated. A bulk (total, wet and dry) deposition and PM₁₀ particle fraction (particles with an equivalent aerodynamic diameter < 10 µm) were collected from June 2020 to May 2021 at an urban residential location in the northern part of Zagreb, Croatia. The monthly average of total equivalent BaP_eq mass concentrations of PM₁₀ varied from 0.057 ng m^-3 in July to 3.656 ng m^-3 in December; the annul ∑BaP_eq average was 1.348 ng m^-3. In bulk deposition, ∑BaP_eq mass concentrations varied from 1.94 to 57.60 ng L^-1. In both investigated media, BaP had the highest contribution in carcinogenic activity. For PM₁₀ media, dermal absorption implied the greatest potential cancer risk, followed by ingestion and inhalation. For bulk media, a moderate ecological risk for BaA, BbF and BaP was observed according to the risk quotient approach.