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High-efficiency particulate air filters are widely used for indoor air purification. Spent filter waste (SFW), which can trap infectious and toxic substances, is primarily treated via incineration. This method causes environmental concerns, particularly regarding the generation of carbon dioxide (CO 2) and other air pollutants. To cope with these issues, this work proposes the pyrolysis of SFW using CO 2 as a sustainable alternative to conventional incineration. The introduction of CO 2 enhanced reactivity during pyrolysis, potentially offering a more sustainable process. The SFW consisted of filtered particles and two distinct filter/support layers, and the presence of toxic chemicals and primary polymer constituents was characterized. While CO 2 had a minimal impact on enhancing syngas production, owing to its slow reaction rate during SFW pyrolysis, adding a nickel-based catalyst significantly improved CO 2 reactivity. This resulted in a 649.7% increase in carbon monoxide (CO) production compared to that in pyrolysis under N 2. The potential of this pyrolysis system for reducing CO 2 emissions was evaluated against that of conventional incineration. Overall, this study presents a promising method for the pyrolytic conversion of SFW into combustible gases, particularly CO, while leveraging CO 2 utilisation to mitigate global warming. [Display omitted] • Particles and constituent polymers in spent filter waste (SFW) were characterized. • Employing CO 2 to pyrolysis identified its interaction with SFW-derived volatiles. • Functionality of CO 2 for producing CO become stronger by adopting a Ni catalyst. • Potential for the CO 2 emission of CO 2 -mediated catalytic pyrolysis was evaluated. [ABSTRACT FROM AUTHOR]

Over the past two decades, ambient O 3 air pollution in Seoul, the capital city of South Korea, has increased. As a secondary air pollutant, O 3 is affected not only by precursor gas emissions but also by meteorological conditions. This study examined the influence of weather changes in Seoul for 2001–2019 on the long-term daily maximum 8-h O 3 concentration (MDA8 O 3) trends measured at 25 monitoring sites. As the relationship between O 3 and meteorological variables may not be linear, we used a generalized additive model framework to estimate O 3 trends, incorporating quantile and logistic regressions for continuous O 3 data and O 3 exceedance days (>60 ppb), respectively. Over the 19-year period, the O 3 concentrations in Seoul increased by 14.7 (SD = 3.2) and 13.1 (SD = 3.1) ppb before and after adjusting for local meteorology, respectively, resulting in an average weather penalty of 1.55 ppb. Seasonal variations in the penalty were substantial, showing a greater penalty (4.5 ppb) during the warm season (May–October) than during the cold season (November–April). Furthermore, the increase in O 3 concentration was more pronounced on days with comparatively high O 3 levels. During the warm season, the weather penalties on O 3 trends reached 3.7–4.0 ppb on high-O 3 days (75th, 95th, and 99th percentiles). From 2001 to 2019, the O 3 exceedance days started 2.66 days earlier and ended 2.30 days later per year, extending the peak-O 3 season by approximately 89 days in total. Weather changes accelerated the upward trend in the odds ratio of O 3 exceedance days by 3.8 years. Our findings indicate that O 3 exceedance days can occur in nearly all months owing to weather changes. The significant weather penalties on O 3 concentrations and exceedance days emphasize the need for a comprehensive O 3 air pollution mitigation strategy, considering non-emission factors that are increasingly being recognized in the context of climate change. [Display omitted] • Ambient ozone air pollution in Seoul has increased over the past two decades. • Influence of weather changes on long-term O 3 pollution trends was explored. • Before and after adjusting for meteorology, O 3 increased by 14.7 and 13.1 ppb. • Peak-O 3 season has increased by 89 days driven by weather changes. [ABSTRACT FROM AUTHOR]

Air pollution, particularly fine particulate matter less than 2.5 μm in diameter (PM 2.5), contributes to respiratory and cardiovascular diseases and poses significant public health risks worldwide. This study evaluated the short-term effects of PM 2.5 on hospital admissions for cardiovascular and respiratory diseases, with additional analyses to identify vulnerable populations based on regional characteristics. The present study analyzed data from 249 Korean communities between 2006 and 2021. Data on daily hospital admissions for cardiovascular and respiratory diseases were obtained from the National Health Insurance Service. Data on PM 2.5 concentrations were sourced from air quality modeling. Additional data on regional characteristics, including the regional deprivation index, proportion of elderly residents, education levels, and greenness levels, were also collected. We used case time series analysis to assess the associations between PM 2.5 concentrations and hospital admissions for cardiovascular and respiratory diseases and explored effect modification by regional characteristics with stratified analyses. The mean numbers of daily cardiovascular admissions and respiratory admissions were 5.68 ± 5.46 and 6.46 ± 8.03, respectively. The mean PM 2.5 concentrations were 23.58 ± 13.66 μg/m3. A10 μg/m³ increment in daily PM 2.5 concentration was associated with increase of cardiovascular and respiratory hospitalization by 0.94% (95% CI: 0.84%, 1.04%) and 1.43% (95% CI: 1.34%, 1.52%), respectively. Regional characteristics analysis showed significant disparities, with higher risks for hospital admissions in areas with lower deprivation and low greenness. This study highlights the significant short-term health impacts of PM 2.5 on respiratory and cardiovascular hospital admissions in Korean communities. The findings underscore the critical role of regional and demographic factors in modulating these effects, identifying socio-economic areas, age structure of the population, lower education levels, and low greenness as key vulnerability factors. [Display omitted] • We conducted a nationwide case-time series analysis to examine the association between PM 2.5 exposure and hospital admission. • PM 2.5 exposures significantly increase the risk of cardiovascular and respiratory hospital admission. • A 10 μg/m³ increase in PM 2.5 is associated with a 0.94% rise in cardiovascular, 1.43% in respiratory hospitalization. • Areas with lower socioeconomic deprivation and lesser greenness show higher risks. • Mandatory graphical abstract. [ABSTRACT FROM AUTHOR]

The relationship between air pollution and the risk of systemic lupus erythematosus (SLE) remains inconclusive. Here, we investigated the associations between long-term exposure to ambient air pollutants and incident SLE, based on a cohort of 502,004 participants free of SLE at baseline from UK Biobank. During a median of 13.65 follow-up years, 638 patients with SLE were identified. For each increase of interquartile range in air pollutant concentrations, the hazard ratios (HRs) and 95% confidence intervals (CIs) of SLE were 1.15 (1.04–1.27) for nitrogen dioxide (NO 2), 1.08 (1.00–1.17) for nitrogen oxides (NO x), 1.13 (1.03–1.24) for particulate matter with the diameters ≤2.5 μm (PM 2.5), 1.06 (0.99–1.14) for particulate matter with diameter between 2.5 μm and 10 μm (PM coarse), and 1.10 (1.02–1.18) for particulate matter with diameter ≤10 μm (PM 10), respectively. A non-linear relationship of PM coarse with SLE risk was detected by using restricted cubic spline models (P non-linearity = 0.009), but not for the remaining air pollutants. Furthermore, smoking and long-term exposure to PM pollutants had significant additive interaction on SLE risk, with a relative excess risk of additive interaction (RERI) of 0.07 (95% CI: 0.02–0.09) for PM 2.5 , and 0.05 (95% CI: 0.01–0.08) for PM 10. Additive interactions were also observed for genetic risk and PM coarse (RERI: 0.04, 95% CI: 0.00–0.07) and PM 10 (RERI: 0.04, 95% CI: 0.02–0.06) on SLE risk. In conclusion, our findings emphasize the significance of evaluating the impacts of long-term exposure to ambient air pollutants in preventing SLE, and highlight the necessity to identify individuals who smoke and have a high genetic risk to minimize the harmful effects of air pollution on the development of SLE. [Display omitted] • Limited evidence has linked air pollutant to the risk of systemic lupus erythematosus (SLE). • Long-term exposure to NO X , NO 2 , PM 2.5 , PM coarse, and PM 10 was associated with an increased risk of SLE. • The associations of air pollutants with SLE risk could be enhanced by genetic risk and smoking. [ABSTRACT FROM AUTHOR]

The influence of transboundary air pollutants originating from the Asian continent on South Korea has been a major concern. Although organochlorine pesticides (OCPs) have been banned for several decades, they continue to be detected in the Korean environment. However, studies on the long-range atmospheric transport (LRAT) of OCPs in South Korea, particularly in background areas, remain limited. This study investigated the atmospheric levels, sources, and behavior of OCPs at Deokjeok Island, a background site near the west coast of the Korean Peninsula. Total concentrations of 24 OCPs ranged from 53.6 to 325 pg/m3, which are lower than those reported by the national POPs monitoring network of South Korea and similar to levels found in other background regions in Northeast Asia. HCB (62.7 pg/m3, 45%) and PeCB (46.6 pg/m3, 33%) were the most dominant OCPs in the gaseous phase, whereas DDTs were predominant (1.65 pg/m3, 44%) in the particulate phase. Gaseous OCPs were strongly influenced by past use and re-emissions, while ongoing emissions and LRAT were the major sources of particulate OCPs. The consistent detection of mirex provides strong evidence of LRAT. In addition, correlation analysis and the Clausius-Clapeyron equation indicated that DDTs were significantly influenced by LRAT. Concentration-weighted trajectory maps identified East, North, and Northeast China as the major source regions for gaseous OCPs, driven by re-emissions, while the primary source areas for particulate OCPs were Beijing, Hebei, Tianjin, and Shandong. Air/soil fugacity fractions showed equilibrium or net deposition for most OCPs (except PeCB), indicating the dynamic environmental behavior of OCPs influenced by past use and LRAT. This study provides evidence of LRAT of OCPs to South Korea, demonstrating the significant impact of transboundary pollution. These results highlight the importance of ongoing monitoring of both historically and currently used pesticides at receptor sites in Northeast Asia. [Display omitted] • OCP levels and their sources were assessed at a background site in South Korea. • Gaseous OCPs were significantly influenced by past use. • Particulate OCPs likely originated from recent emissions and LRAT. • Consistent detection and modeling results provide strong evidence of LRAT for OCPs. • Past use and LRAT play key roles in the dynamic environmental behavior of OCPs. [ABSTRACT FROM AUTHOR]

Assessing the aquatic toxicity originating from air pollutants is essential in sustaining water resources and maintaining the ecosystem's safety. Quantitative structure-activity relationship (QSAR) models provide a computational tool for predicting pollutant toxicity, facilitating the identification/evaluation of the contaminants and identifying responsible structural fragments. One-vs-all (OvA) QSAR is a tailored approach to address multi-class QSAR problems. The study aims to determine five distinct levels of aquatic hazard categories for airborne pollutants using OvA-QSAR modeling containing 254 air contaminants. This QSAR analysis reveals the critical descriptors of air pollutants to target for molecular modification. Various factors, including the selection of relevant mechanistic descriptors, data quality, and outliers, determine the reliability of QSAR models. By employing feature selection and outlier identification approaches, the robustness and accuracy of our QSAR models were significantly increased, leading to more reliable predictions in chemical hazard assessment. The results revealed that models using the Random Forest algorithm performed the best based on the selected descriptors, with internal and external validation accuracy ranging from 71.90% to 97.53% and 76.47%–98.03%, respectively. This study indicated that the aquatic risk of air contaminants might be attributed predominantly to their sp3/sp2 carbon ratio, hydrogen-bond acceptor capability, hydrophilicity/lipophilicity, and van der Waals volumes. These structures can be critical in developing innovative strategies to mitigate or avoid the chemicals' harmful effects. Supporting air quality improvement, this study contributes to the rapid implementation of measures to protect aquatic ecosystems affected by air pollution. [Display omitted] • OvA-QSAR accurately identifies aquatic hazard classes of air pollutants. • The model fills the literature gap in air pollutants' aquatic hazards. • Identification of specific molecular descriptors for toxicity risk reduction. • Computational models aid in the design of environmental management policies. • In silico approaches are replacing animal-based toxicity testing. [ABSTRACT FROM AUTHOR]

Air pollution and particulate matter (PM) are the leading environmental cause of death worldwide. Exposure limits have lowered to increase the protection of human health; accordingly, it becomes increasingly important to understand the toxicological mechanisms on cellular models at low airborne PM concentrations which are relevant for actual human exposure. The use of air liquid interface (ALI) models, which mimic the interaction between airborne pollutants and lung epithelia, is also gaining importance in inhalation toxicological studies. This study reports the effects of ALI direct exposure of bronchial epithelial cells BEAS-2B to ambient PM 1 (i.e. particles with aerodynamic diameter lower than 1 μm). Gene expression (HMOX, Cxcl-8, ATM, Gadd45-a and NQO1), interleukin (IL)-8 release, and DNA damage (Comet assay) were evaluated after 24 h of exposure. We report the dose-response curves of the selected toxicological outcomes, together with the concentration-response association and we show that the two curves differ for specific responses highlighting that concentration-response association may be not relevant for understanding toxicological outcomes. Noteworthy, we show that pro-oxidant effects may be driven by the deposition of freshly emitted particles, regardless of the airborne PM 1 mass concentration. Furthermore, we show that reference airborne PM 1 metrics, namely airborne mass concentration, may not always reflect the toxicological process triggered by the aerosol. These findings underscore the importance of considering different aerosol metrics to assess the toxicological potency of fine and ultrafine particles. To better protect human health additional metrics should be defined, than account for the properties of the entire aerosol mixture including specific as particle size (i.e. particles with aerodynamic diameter lower than 20 nm), the relevant aerosol sources (e.g., traffic combustion, secondary organic aerosol ...) as well as their atmospheric processing (freshly emitted vs aged ones). [Display omitted] • Oxidative responses are induced by freshly emitted combustion particles. • DNA damage responses are associated to organic aerosol species. • To be protective for health mass or number metrics must be associated with composition/aging information. • The black carbon to organic carbon ratio is a good proxy for composition/aging and relevant to understanding PM toxicology. • Effects reported as dose-response curves may differ from concentration-response ones. [ABSTRACT FROM AUTHOR]

Regional water scarcity is among the most urgent challenges of global climate change. Atmospheric water harvesting is a promising method to mitigate these challenges, and the atmospheric water generator (AWG) is already an established technology. Although this method can produce over 10,000 L of water per day, the water's quality has not been studied in depth. Air pollutants, especially volatile organic compounds (VOCs), are potential contaminants of water produced from air. We evaluated the chemical and physical parameters of different VOCs that might influence their ability to be transferred from air to AWG water. Our findings strongly suggest that the ability to form hydrogen bonds is a key factor in this transfer. Henry's law constant, polarity, and intrinsic solubility were the main predictors of a VOC's transfer to AWG water. Hence, aliphatic or aromatic compounds (such as benzene or octane) were not found at significant concentrations in AWG water (e.g. above WHO guidelines), whereas ammonia and alcohol compounds were. This should be taken into consideration when analyzing potential contaminants in harvested atmospheric water. The condensation process itself was also found to enhance the transfer of VOCs into water droplets, and higher relative humidity (%RH) also increased VOC transfer. Gas-phase infrared spectrum analysis of VOCs at different %RH revealed possible interactions between water vapor and specific VOCs in the air. However, our main conclusion from this study is that VOC transfer from the air into AWG water occurs predominantly via dissolution in the condensed droplets, and strongly depends on their chemical properties of polarity and hydrogen-bond formation. [Display omitted] • The transfer of VOCs into harvested atmospheric water is significantly influenced by their polarity and Henry's constant. • Hydrogen-bond formation is a key factor in VOC transfer to harvested water. • Droplet condensation enhances VOC transfer to harvested water, primarily through the dissolution of VOCs on water droplets. • High relative humidity increases the presence of airborne VOCs in harvested water. [ABSTRACT FROM AUTHOR]

Exposure to air pollutants like sulfur dioxide (SO 2), nitrogen oxides (NO x), and ozone (O 3) is associated with adverse health effects, particularly with exacerbations of asthma symptoms and new asthma cases in both children and adults. While fixed-site monitoring (FSM) stations are commonly used in air pollutant exposure studies, they may not fully capture personal exposures due to limitations such as inadequate consideration of daily routines and indoor/outdoor concentration variations. In this study, to enhance the accuracy of personal exposure calculated by using FSM data, individual's daily activity routine, encompassing both indoor and outdoor environments, were incorporated by using indoor-to-outdoor concentration ratios. Three methodologies were compared to assess the accuracy of exposure calculations: (i) direct exposure determination employing passive samplers (PS), (ii) personal exposure calculated using FSM data alone, and (iii) personal exposure calculated using FSM data refined by integrating local average individual daily activity routines and indoor-to-outdoor ratios. The results demonstrate that the refined method (iii) yields substantial improvements in estimated exposure levels, reducing the average error from 1.4% to 0.4% for NO 2 , from 72.1% to 12.7% for SO 2 , and from 323.4% to 24.9% for O 3. [Display omitted] • Fixed Site Monitoring data alone overestimates personal exposure to air pollutants. • Passive samplers match reference methods, proving exposure assessment's reliability. • Refined Fixed Site Monitoring data using I/O and routines improved exposure estimate. • Refined exposure estimates align closer to personal passive sampler data. • Local I/O ratios and daily activities are essentials to enhance exposure estimates. [ABSTRACT FROM AUTHOR]

Airborne Organic Pollutants (AOPs) reach remote oceanic regions after long range atmospheric transport and deposition, incorporating into natural microbial communities. This study investigated the effects of AOPs on natural microbial communities of the Mediterranean Sea, the Atlantic Ocean and the Bellingshausen Sea, by assessing the impact of both non-polar and polar AOPs on cell abundances, chlorophyll a concentrations and cell viabilities of different microbial groups. Our results indicate that almost all groups, except flagellates in the Bellingshausen Sea, were significantly affected by AOPs. While no significant differences in chlorophyll a concentrations were observed between non-polar and polar AOPs, significant variations in cell abundances were noted. Cell death occurred at AOP concentrations as low as five times the oceanic field levels, likely due to their high chemical activity. Cyanobacteria in temperate waters exhibited the highest sensitivity to AOPs, whereas medium and larger diatoms in the Bellingshausen Sea were more affected than smaller diatoms or flagellates, contrary to the expected size-related sensitivity trend. Additionally, microorganisms in temperate waters were more sensitive to the polar fraction of AOPs compared to the non-polar fraction, which showed an inverse sensitivity pattern. This differential sensitivity is attributed to variations in the ratio of polar to non-polar AOPs in the respective environments. Our findings underscore the varying impacts of AOPs on marine microbial communities across different oceanic regions. [Display omitted] • Airborne organic pollutants impacted natural phytoplankton communities. • Cell death was induced at five fold the field oceanic concentrations. • In Antarctic seawaters, the largest diatoms were the most affected. • In temperate seawaters, the smallest cyanobacteria were the most affected. • Higher sensitivity to the airborne polar mixture and the seawater non-polar mixture. [ABSTRACT FROM AUTHOR]

Fine particulate matter (PM 2.5) is an air pollutant that enhances susceptibility to cardiovascular diseases. Macrophages are the first immune cells to encounter the inhaled particles and orchestrate an inflammatory response. Given their role in atherosclerosis development, we investigated whether aqueous PM 2.5 could elicit atherogenic effects by polarising macrophages to a pro-oxidative and pro-inflammatory phenotype and enhancing foam cell formation. The RAW264.7 macrophage cell line was exposed to PM 2.5 for 48 h, with PBS as the control. Aqueous PM 2.5 induced apoptosis and reduced cell proliferation. In surviving cells, we observed morphological, phagocytic, oxidative, and inflammatory features (i.e. enhanced iNOS, Integrin-1β, IL-6 expression), indicative of classical macrophage activation. We also detected an increase in total and surface HSP70 levels, suggesting macrophage activation. Further, exposure of high-cholesterol diet-fed mice to PM 2.5 resulted in aortic wall enlargement, indicating vascular lesions. Macrophages exposed to PM 2.5 and non-modified low-density lipoprotein (LDL) showed exacerbated lipid accumulation. Given the non-oxidised LDL used and the evidence linking inflammation to disrupted cholesterol negative feedback, we hypothesise that PM 2.5 -induced inflammation in macrophages enhances their susceptibility to transforming into foam cells. Finally, our results indicate that exposure to aqueous PM 2.5 promotes classical macrophage activation, marked by increased HSP70 expression and that it potentially contributes to atherosclerosis. [Display omitted] • Aqueous PM 2.5 is cytotoxic to macrophage. • Aqueous PM 2.5 stimulates macrophage phagocytic activity. • Aqueous PM 2.5 polarises macrophages to an oxidative and inflammatory phenotype. • HSP70 may mark macrophage reactivation in polluted conditions. • PM 2.5 enhances lipid accumulation by macrophage. [ABSTRACT FROM AUTHOR]

Thermosetting polymers are used in a wide range of applications due to their robust mechanical strength and superior flame retardancy. Despite these technical benefits, recycling of thermosetting polymers has been challenging because of their crosslinking nature. Moreover, their disposal through conventional methods (landfill and combustion) poses environmental concerns, such as microplastics and air pollutants. To address these issues, this study introduces a thermo-chemical disposal platform for thermosetting polymer wastes that employs carbon dioxide (CO 2) as a reactive medium. In this work, melamine-formaldehyde was used as model compound of thermosetting polymers. In single-stage pyrolysis, it was revealed that CO 2 plays a crucial role in controlling in the compositional matrices of pyrolytic gases, liquid products, and wax. These compositional changes were attributed to the homogeneous reactions between CO 2 and the volatile compounds released from the thermolysis of MF. To enhance the thermal cracking of the MF, a double-stage pyrolysis process was tested, which increased the production of pyrolytic gases and eliminated wax formation. However, the slow kinetics governing the reactivity of CO 2 limits the occurrence of homogeneous reactions. A nickel-based catalyst was used to accelerate reaction kinetics. The catalytic pyrolysis under CO 2 conditions led to substantial increases in syngas (H 2 and CO) production of 880% and 460%, respectively, compared with double-stage pyrolysis. These findings demonstrate that thermosetting polymer wastes can be valorized into gaseous fuels through thermo-chemical process, and CO 2 enhances the recovery of energy and chemicals. Therefore, this study presents an innovative technical platform to convert thermosetting polymer wastes and CO 2 into syngas. [Display omitted] • A sustainable pyrolysis framework for disposal of MF waste was suggested. • CO 2 plays a crucial role in controlling composition of the pyrogenic products of MF. • MF was converted to value-added products through pyrolysis. • Ni-based catalyst resulted in CO enhancements 5 times higher under N 2 condition. [ABSTRACT FROM AUTHOR]

Regular monitoring of the air pollutant nitrogen dioxide (NO 2), an indicator for traffic-related emissions, is a priority in urban environments. The health impacts associated with NO 2 exposure are the result of a combination of factors, including concentration, duration of exposure, and interactions with other pollutants. WHO has established air quality guidelines based on epidemiological studies. This study develops a new concept "Health Impact Pathways (HIPs)" using adversity as a probabilistic indicator of health effects. For this purpose, it integrates available toxicological and epidemiological information, using Adverse Outcome Pathways (AOPs), in order to understand chemical-biological interactions and their consequences on health. Literature review and meta-analysis of toxicological data supported by expert judgment were performed to establish: a) adversity pathways, b) quantitative criteria for scoring the observed toxicological effects (adversity indicators), c) NO 2 exposure - adversity relationship for both long-term (1–36 months) and shortterm (1–7 days). The NO 2 daily concentrations from January 2001 to December 2022, were obtained from Madrid city Air Quality network monitoring database. Adversity levels were compared with relative risk levels for all-cause and respiratory mortality estimated using linear equations from WHO 2021 guidelines. Non-linear relations were obtained for all long- and short-term NO 2 related adversity indicators; for long-term effects, the best fitting was obtained with a modified Haber's law model with an exponential coefficient for the exposure time of 0.25. Estimations are presented for a set of case studies for Madrid city, covering temporal and spatial variability. A clear improvement trend along the two decades was observed, as well as high inter- and intra-station variability; the adversity indicators provided integrated information on the temporal and spatial evolution of population level risk. The proposed HIP conceptual approach offers promising advances for integrating experimental and epidemiological data. The next step is linking the concentration-adversity relationship with population health impacts through probability estimations, the preliminary estimations confirm the need for assessing independently different population groups. [Display omitted] • Extending AOP as Health Impact Pathways-HIP gives quantitative adversity estimates. • The HIP conceptual approach integrates experimental tox and epidemiological data. • Nonlinearity of NO 2 -related long/short-term health impacts must feed trend analysis. • The estimates confirm the need to independently assess different population groups. [ABSTRACT FROM AUTHOR]

Current knowledge suggests that the gene region containing MUC5B and TOLLIP plays a role in airway defence and airway inflammation, and hence respiratory disease. It is also known that exposure to air pollution increases susceptibility to respiratory disease. We aimed to study whether the effect of air pollutants on the immune response and respiratory symptoms in infants may be modified by polymorphisms in MUC5B and TOLLIP genes. 359 healthy term infants from the prospective Basel-Bern Infant Lung Development (BILD) birth cohort were included in the study. The main outcome was the score of weekly assessed respiratory symptoms in the first year of life. Using the candidate gene approach, we selected 10 single nucleotide polymorphisms (SNPs) from the MUC5B and TOLLIP regions. Nitrogen dioxide (NO 2) and particulate matter ≤10 μm in aerodynamic diameter (PM 10) exposure was estimated on a weekly basis. We used generalised additive mixed models adjusted for known covariates. To validate our results in vitro , cells from a lung epithelial cell line were downregulated in TOLLIP expression and exposed to diesel particulate matter (DPM) and polyinosinic-polycytidylic acid. Significant interaction was observed between modelled air pollution (weekly NO 2 exposure) and 5 SNPs within MUC5B and TOLLIP genes regarding respiratory symptoms as outcome: E.g., infants carrying minor alleles of rs5744034, rs3793965 and rs3750920 (all TOLLIP) had an increased risk of respiratory symptoms with increasing NO 2 exposure. In vitro experiments showed that cells downregulated for TOLLIP react differently to environmental pollutant exposure with DPM and viral stimulation. Our findings suggest that the effect of air pollution on respiratory symptoms in infancy may be influenced by the genotype of specific SNPs from the MUC5B and TOLLIP regions. For validation of the findings, we provided in vitro evidence for the interaction of TOLLIP with air pollution. [Display omitted] • SNPs in the MUC5B and TOLLIP regions modify infants' susceptibility to NO2. • This may help identify infants more susceptible to air pollution effects on the lungs. • Downregulation of TOLLIP alters cell reactions to pollutants (in vitro analysis). [ABSTRACT FROM AUTHOR]

A significant concern in our society is the potential impact on both health and the environment of air pollutants released during the incineration of waste. Therefore, it is crucial to conduct thorough control and monitoring measures. In this context, the objective of this research was to study the evolution of particulate matter (PM 2.5) and associated trace elements during the period before and after the installation of an Energy Recovery Plant (ERP). For that, a descriptive and temporal analysis of PM 2.5 concentration and composition were performed on two similar areas (impact/control) using the Before-After/Control-Impact (BACI) design and two periods (before from January 01, 2018 to February 06, 2020 and after from December 10, 2020 to September 30, 2022). Results showed a decrease in the levels of PM 2.5 and associated trace elements is observed in the impact zone (IZ) and in the control zone (CZ) throughout the study period. In the case of PM 2.5 , the most notable decrease occurred in the period of the start-up of the ERP, a period that coincides with the confinement and restrictions of COVID, with a subsequent increase in both zones, without reaching the levels observed in the period prior to the start-up of the ERP. Selenium is the only trace element that increases significantly in the IZ. In conclusion, a decrease is observed for all pollutants except selenium in both zones, although less pronounced in the IZ. Since selenium already showed an upward trend in the phase prior to the start of the ERP, it is necessary to investigate its evolution and find out the possible cause. [Display omitted] • Air quality assessment with BACI design after the start-up of an ERP. • PM 2.5 and trace elements levels remained below pre-ERP levels. • Selenium was the only pollutant with increased levels in the post-ERP period. [ABSTRACT FROM AUTHOR]

The present study examines indoor air pollution in health facilities, focusing on compounds from various sources, such as industrial products, healthcare activities and building materials. It assesses chemical and microbiological concentrations in two public hospitals, two public healthcare centres, and one public health laboratory in Spain. Measurements included indoor air quality, microbiological contaminants, ambient parameters and non-target analysis across ten different locations. Outdoor air quality was also assessed in the surroundings of the hospitals. The results showed that around 350 substances were tentatively identified at a high confidence level, with over 50 % of compounds classified as of high toxicological risk. Three indoor and 26 outdoor compounds were fully confirmed with standards. These confirmed substances were linked to medical, industrial and agricultural activities. Indoor Air Quality (IAQ) results revealed that CO, CO 2 , formaldehyde (HCHO), O 3 and total volatile organic compounds (TVOCs) showed average values above the recommended guideline levels in at least one of the evaluated locations. Moreover, maximum concentrations detected for CO, HCHO, O 3 and TVOCs in hospitals surpassed those previously reported in the literature. SARS-CoV-2 was detected in three air environments, corresponding to COVID-19 patient areas. Fungi and bacteria concentrations were acceptable in all assessed locations, identifying different fungi genera, such as Penicillium , Cladosporium , Aspergillus , Alternaria and Botrytis. [Display omitted] • For the first time, pollutants surrounding healthcare facilities were studied. • More than 350 substances were detected using non-target strategies. • 26 substances were confirmed in outdoor and indoor air using analytical standards. • Some pollutants in indoor air revealed average values above guideline values. • SARS-CoV-2 was detected in the air in COVID-19 patient environments. [ABSTRACT FROM AUTHOR]

Passive air samplers were used to monitor polychlorodibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorobiphenyls (dl-PCBs) between 2020 and 2022 in four residential areas around Bien Hoa hot spot (BHS) including Trung Dung (TD), Tan Phong (TP), Quang Vinh (QV), and Buu Long (BL). The total toxic equivalents of PCDD/Fs and dl-PCBs (∑TEQs) were highest in the TD area, from 284 to 642 fg TEQ/PUF day. Next was the QV area, where ∑TEQs ranged from 229 to 569 fg TEQ/PUF day. Then, ∑TEQs varied from 205 to 503 fg TEQ/PUF day in the TP area. The lowest ∑TEQs were between 179 and 385 fg TEQ/PUF day in the BL area. The temporal, spatial, and seasonal variations in concentrations of PCDD/Fs and dl-PCBs were related to the prevailing wind direction and the distance from each area to the dioxin hot spot. The average ∑TEQs for all four areas surrounding BHS in the dry season (423 fg TEQ/PUF day) were 1.4 times higher than in the rainy season (303 fg TEQ/PUF day). Health risk assessments from airborne dioxin exposure were estimated using the average daily doses through inhalation (ADDI). The ADDI for residents surrounding BHS ranged from 14.6 to 208 fg TEQ/kg BW/day. The ADDI values by areas were as follows: 23.2-208 fg TEQ/kg BW/day in the TD, 18.7-184 fg TEQ/kg BW/day in the QV, 16.7-163 fg TEQ/kg BW/day in the TP, and 14.6-125 fg TEQ/kg BW/day in the BL. These ADDI values remained within and below the 10% threshold of the WHO-recommended tolerable daily intake (100-400 fg TEQ/kg BW/day). It is necessary to control the excavation activities inside the BHS and cover the temporary storage sites of dioxin-contaminated materials to minimize the emissions of PCDD/Fs and dl-PCB into the ambient air., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The COVID-19 pandemic has reinforced an interest in the relationship between air pollution and respiratory viral infections, indicating that their burden can be increased under poor air quality. This paper reviews the pathways through which air pollutants can enhance susceptibility to such infections and aggravate their clinical course and outcome. It also summarizes the research exploring the links between various viral infections and exposure to solid and gaseous pollution in Poland, a region characterized by poor air quality, especially during a heating season. The majority of studies focused on concentrations of particulate matter (PM; 86.7%); the other pollutants, i.e., BaP, benzene, CO, NO x , O 3 , and SO 2, were studied less often and sometimes only in the context of a particular infection type. Most research concerned COVID-19, showing that elevated levels of PM and NO 2 correlated with higher morbidity and mortality, while increased PM 2.5 and benzo[a]pyrene levels were related to worse clinical course and outcome in hospitalized, regardless of age and dominant SARS-CoV-2 variant. PM 10 and PM 2.5 levels were also associated with the incidence of influenza-like illness and, along with NO 2 concentrations, with a higher rate of children's hospitalizations due to lower respiratory tract RSV infections. Higher levels of air pollutants also increased hospitalization due to bronchitis (PM, NO x , and O 3) and emergency department admission due to viral croup (PM 10 , PM 2.5 , NO x , CO, and benzene). Although the conducted studies imply only correlations and have other limitations, as discussed in the present paper, it appears that improving air quality through reducing combustion processes in energy production in Poland should be perceived as a part of multilayered protection measures against respiratory viral infections, decreasing the healthcare costs of COVID-19, lower tract RSV infections, influenza, and other respiratory viral diseases prevalent between autumn and early spring, in addition to other health and climate benefits. [Display omitted] • Polluted air may increase the severity of respiratory viral infections. • Poland is a PM and BaP pollution hot spot in Europe. • Air pollution is associated with a higher burden of respiratory viral infections. • Improving the air quality should be a protection measure against infections. • Further studies are encouraged to explore the relationships with other pathogens. [ABSTRACT FROM AUTHOR]

Volatile organic compounds (VOCs) are crucial air pollutants in indoor environments, emitted from building materials, furniture, consumer products, cleaning products, smoking, fuel combustion, cooking, and other sources. VOCs are also emitted from human beings via breath and whole-body skin. Some VOCs cause dermal/ocular irritation as well as gastrointestinal, neurological, cardiovascular, and/or carcinogenic damage to human health. Because people spend most of their time indoors, active control of indoor VOCs has garnered attention. Phytoremediation and microbial remediation, based on plant and microorganism activities, are deemed sustainable, cost-effective, and public-friendly technologies for mitigating indoor VOCs. This study presents the major sources of VOCs in indoor environments and their compositions. Various herbaceous and woody plants used to mitigate indoor VOCs are summarized and their VOCs removal performance is compared. Moreover, this paper reviews the current state of active phytoremediation and microbial remediation for the control of indoor VOCs, and discusses future directions. [Display omitted] • With well-known sources, humans are notable indoor VOCs sources. • Various herbaceous/woody plants are employed to mitigate indoor VOCs. • Most studies on phyto- & microbial remediation for indoor VOCs remains at Lab-scales. • Synergistic interaction of plant-microbe can enhance indoor VOCs removal. • Long-term field tests are needed to innovate biotechnology for indoor VOCs control. [ABSTRACT FROM AUTHOR]

In the electrical industry, there are many hazardous gases that pollute the environment and even jeopardize human health, so timely detection and effective control of these hazardous gases is of great significance. In this work, the gas-sensitive properties of Pd-modified g-C 3 N 4 interface for each hazardous gas molecule were investigated from a microscopic viewpoint, taking the hazardous gases (CO, NO x) that may be generated in the power industry as the detection target. Then, the performance of Pd-modifiedg-C 3 N 4 was evaluated for practical applications as a gas sensor material. Novelly, an unconventional means was designed to briefly predict the effect of humidity on the adsorption properties of this sensor material. The final results found that Pd-modified g-C 3 N 4 is most suitable as a potential gas-sensitizing material for NO 2 gas sensors, followed by CO. Interestingly, Pd-modified g-C 3 N 4 is less suitable as a potential gas-sensitizing material for NO gas sensors, but has the potential to be used as a NO cleaner (adsorbent). Unconventional simulation explorations of humidity effects show that in practical applications Pd-modified g-C 3 N 4 remains a promising material for gas sensing in specific humidity environments. This work reveals the origin of the excellent properties of Pd-modified g-C 3 N 4 as a gas sensor material and provides new ideas for the detection and treatment of these three hazardous gases. [Display omitted] • The sensing properties of Pd-modified g-C 3 N 4 interface were evaluated for CO, NO x. • A new experiment for the prediction of humidity-influenced interface performance was designed. • This work enriches new schemes for the preparation of g–C 3 N 4 –based gas sensors. • This work provides new ideas for addressing hazardous gases generated in the electrical industry. [ABSTRACT FROM AUTHOR]

Globally, air pollution is an unfortunate aftermath of rapid industrialization and urbanization. Although the best strategy is to prevent air pollution, it is not always feasible. This makes it imperative to devise and implement techniques that can clean the air continuously. Plants and microbes have a natural potential to transform or degrade pollutants. Hence, strategies that use this potential of living biomass to remediate air pollution seem to be promising. The simplest future trend can be planting suitable plant-microbe species capable of removing air pollutants like SO 2 , CO 2 , CO, NO X and particulate matter (PM) along roadsides and inside the buildings. Established wastewater treatment strategies such as microbial fuel cells (MFC) and constructed wetlands (CW) can be suitably modified to ameliorate air pollution. Green architecture involving green walls and green roofs is facile and aesthetic, providing urban ecosystem services. Certain microbe-based bioreactors such as bioscrubbers and biofilters may be useful in small confined spaces. Several generative models have been developed to assist with planning and managing green spaces in urban locales. The physiological limitations of using living organisms can be circumvent by applying biotechnology and transgenics to improve their potential. This review provides a comprehensive update on not just the plants and associated microbes for the mitigation of air pollution, but also lists the technologies that are available and/or can be modified and used for air pollution control. The article also gives a detailed analysis of this topic in the form of strengths-weaknesses-opportunities-challenges (SWOC). The strategies mentioned in this review would help to attain corporate Environmental Social and Governance (ESG) and Sustainable Development Goals (SDGs), while reducing carbon footprint in the urban scenario. The review aims to emphasise that urbanization is possible while tackling air pollution using facile, green techniques involving plants and associated microbes. [Display omitted] • Rise in air pollution requires implementation of sustainable remediation strategies. • Plants and microbes have a natural potential/capacity to degrade air pollutants. • Strategies using living biomass to remediate air pollution is a promising option. • Green architecture, MFC, CW can be used to treat air pollutants. • Strategies mentioned in this review could help attain the ESG/SD goals. [ABSTRACT FROM AUTHOR]

Little is known about the relationship between long-term joint exposure to mixtures of air pollutants and the prevalence of chronic obstructive pulmonary disease (COPD). We aimed to assess the joint impact of long-term exposure to ambient air pollution on the prevalence of COPD in Korea, especially in areas with high levels of air pollution. We included 22,387 participants who underwent spirometry tests in 2010–2019. The community multiscale air quality model was used to estimate the levels of ambient air pollution at residential addresses. The average exposure over the 5 years before the examination date was used to calculate the concentrations of air pollution. Forced expiratory volume in 1 s and forced vital capacity were used to define restrictive lung disease, COPD, and moderate-to-severe COPD. Quantile-based g-computation models were used to assess the joint impact of air pollution on COPD prevalence. A total of 2535 cases of restrictive lung disease, 2787 cases of COPD, and 1399 cases of moderate-to-severe COPD were identified. In the individual pollutant model, long-term exposure was significantly associated with both restrictive lung disease and COPD. In the mixture pollutant model, the odds ratios (ORs, 95% confidence intervals) for restrictive lung disease increased with each quartile increment in the 1- to 5-year average mixtures: 1.14 (1.02–1.28, 1 year), 1.25 (1.11–1.41, 2 years), 1.26 (1.11–1.42, 3 years), 1.32 (1.16–1.51, 4 years), and 1.37 (1.19–1.58, 5 years), respectively. The increase in ORs of restrictive lung disease accelerated over time. By contrast, the ORs of COPD showed a decreasing trend over time. Long-term exposure to air pollutants, both individually and jointly, was associated with an increased risk of developing COPD, particularly restrictive lung disease. Our findings highlight the importance of comprehensively assessing exposure to various air pollutants in relation to COPD. [Display omitted] • Ambient air pollutant mixture elevated restrictive lung disease and COPD prevalence. • Restrictive lung disease prevalence increased with higher level of mixture exposure. • NO 2 showed the strongest association with COPD, followed by O 3 and CO. • Comprehensively assessing air pollutants exposure is important in relation to COPD. [ABSTRACT FROM AUTHOR]

The focus of the studies presented in the preceding companion paper (Part A: Review) and here (Part B: Applications) is on defining representative emission rates from vegetation for determining the roles of biogenic volatile organic compound (BVOC) emissions in atmospheric chemistry and aerosol processes. The review of previously published procedures for identifying and quantifying BVOC emissions has revealed a wide variety of experimental methods used by various researchers. Experimental details become increasingly critical for quantitative emission measurements of low volatility monoterpenes (MT) and sesquiterpenes (SQT). These compounds are prone to be lost inadvertently by uptake to materials in contact with the sample air or by reactions with atmospheric oxidants. These losses become more prominent with higher molecular weight compounds, potentially leading to an underestimation of their emission rates. We present MT and SQT emission rate data from numerous experiments that include 23 deciduous tree species, 14 coniferous tree species, 8 crops, and 2 shrubs. These data indicate total, normalized (30 degrees C) basal emission rates from

The production of biofuels to be used as bioenergy under combustion processes generates some gaseous emissions (CO, CO 2 , NO x , SO x , and other pollutants), affecting living organisms and requiring careful assessments. However, obtaining such information experimentally for data evaluation is costly and time-consuming and its in situ obtaining for regional biomasses (e.g. , those from Northeast Brazil (NEB) is still a major challenge. This paper reports on the application of artificial neural networks (ANNs) for the prediction of the main air pollutants (CO, CO 2 , NO, and SO 2) produced during the direct biomass combustion (N 2 /O 2 :80/20%) with the use of ultimate analysis (carbon, hydrogen, nitrogen, sulfur, and oxygen). 116 worldwide biomasses were used as input data, which is a relevant alternative to overcome the lack of experimental resources in NEB and obtain such information. Cross-validation was conducted with k-fold to optimize the ANNs and performance was analyzed with the use of statistical errors for accuracy assessments. The results showed an acceptable statistical performance for all architectures of ANNs, with 0.001–12.41% MAPE, 0.001–5.82 mg Nm−3 MAE, and 0.03–52.30 mg Nm−3 RMSE, highlighting the high precision of the emissions studied. On average, the differences between predicted and real values for CO, CO 2 , NO, and SO 2 emissions from NEB biomasses were approximately 0.01%, 10−6%, 0.14%, and 0.05%, respectively. Pearson coefficient provided consistent results of concentration of the ultimate analysis in relation to the emissions studied and effectiveness of the test set in the developed models. [Display omitted] • Assembly of a worldwide database with different lingocellulosic biomasses. • Prediction of main air pollutants (CO, CO 2 , NO, and SO 2) for the selected samples. • Information obtained on Brazilian biomasses without the need for many experiments. • Use of different evaluation metrics to validate the established models. • The ANN's showed differences between predicted and estimated values below 1.0%. [ABSTRACT FROM AUTHOR]

Rapid industrial growth and urbanization have resulted in a significant rise in environmental pollution issues, particularly indoor air pollutants. As a result, it is crucial to design and develop technologies and/or catalysts that are not only cost-effective but also promising high performance and practical applicability. However, achieving this goal has been so far remained a challenging task. Herein, a series of transition metal M − TiO 2 (M = W, Fe, Mn) nanocrystals was prepared for photocatalytic degradation of volatile organic compounds (VOCs), i.e., toluene. Of the nanocomposites tested, W–TiO 2 showed significantly improved photocatalytic activity for VOC degradation under UV irradiation compared to the others. In particular, the optimized W dopant amount of 0.5 wt% resulted in the outstanding degradation performance of toluene (96%) for the obtained W–TiO 2 (0.5%) nanocomposite. Moreover, W–TiO 2 (0.5%) nanocomposite exhibited good stability for 32 h working under high toluene concentration (10 ppm) compared to the pristine TiO 2. The current work demonstrates the potential usage of M − TiO 2 nanocrystals, particularly W–TiO 2 (0.5%), as a promising photocatalyst for efficient VOCs degradation. [Display omitted] • W–TiO 2 exhibited an enhanced photocatalytic efficiency. • Lifetime of W–TiO 2 increased 6.4 times compared with TiO 2. • W–TiO 2 could be regenerated. [ABSTRACT FROM AUTHOR]

Airborne polycyclic aromatic hydrocarbons (PAHs) and their derivatives are of particular concern for population health due to their abundance and toxicity via inhalation. Lung toxicity testing includes exposing lung epithelial cell lines to PAHs in a culture medium containing inorganic species, lipids, proteins, and other biochemicals where the cell response is influenced among others by the toxic chemical accessibility in the medium. While inhalation bioaccessibility of PAHs and other toxicants was previously studied in surrogate lung fluids, studies measuring bioaccessibility in cell culture media are rare. In this work, a method was developed to characterize PAH bioaccessibility in a culture medium used for mouse lung epithelial (FE1) cells. Further, the optimised method was tested using commercially available standard reference material of urban particulate matter (PM) as well as polyurethane foam passive air samplers (PUF-PAS). The method provided a high precision and recovery of analytes, indicating no losses during sample processing and analysis. PAHs had non-linear concentration-responses, with the culture medium approaching saturation with PM concentration of 500 μg mL−1. The results showed that phenanthrene, a 3-ring PAH, was significantly more bioaccessible than ≥4-ring congeners in the culture medium (up to ∼2.5 folds; p < 0.05). Finally, using pre-deployed PUF-PAS from a residential and an industrial site, five PAHs were found in the culture medium, including naphthalene, phenanthrene, anthracene, fluoranthene, and pyrene. This work provides a proof of concept to enable future studies to assess the inhalation bioaccessibility of polycyclic aromatic compounds and other airborne pollutants collected using PUF-PAS. [Display omitted] • Bioaccessibility of PAHs in lung epithelial cell culture medium was studied. • High method precision and recovery was achieved, indicating no analyte losses. • Hydrophilicity affected PAH bioaccessibility from PM. • Several bioaccessible PAHs found from passive air samples in culture medium. • Study provides proof of concept enabling similar future works using PUF-PAS. [ABSTRACT FROM AUTHOR]

Ambient air pollution increases the risk of respiratory mortality and morbidity, but evidence concerning effects of air pollution on chronic bronchitis (CB) is scarce. This study aimed to evaluate the associations of a set of air pollutants with the burden of CB, and to explore potential modifiers on the associations. In 2020, a total of 6,556,440 adults living in the Northwestern region of China were recruited. The Space-Time Extra-Trees model was employed to assess the annual average concentrations of six air pollutants for the three years (2017-2019) before 2020 , and subsequently allocated to the participants based on the latitude and longitude of their home addresses. We investigated the associations between the levels of various air pollutants and the odds of CB using generalized linear mixed models, and conducted multiple sensitivity analyses and subgroup analyses. The odds of CB displays an approximately linear association with particulate matter with aerodynamic diameter ≤2.5 μm (PM 2.5), particulate matter with aerodynamic diameter ≤10 μm (PM 10), while it shows a non-linear relationship with gaseous pollutants. In the adjusted model, the odds ratios and 95% confidence intervals for CB per 10 μg/m3 increase in PM 2.5 , PM 10 , and sulfur dioxide (SO 2) were 1.297 (1.262–1.332), 1.072 (1.064–1.080), and 2.587 (2.186–3.063), respectively. Furthermore, several additional sensitivity analyses demonstrated the stability of these associations. Subgroup analyses found that the aforementioned associations were greater among participants aged below 50 years old and those who smoked and had no leisure time exercise. Long-term exposure to ambient air pollutants may increase the odds of CB, especially among younger people and those with unhealthy lifestyles. [Display omitted] • Evidence concerning ambient air pollution and chronic bronchitis (CB) is limited. • We examined the association between air pollution and CB in northwestern China. • Exposure to particulate and gaseous pollutants was related to higher odds of CB. • Our findings may help develop individual-and population-level interventions to reduce CB burden. [ABSTRACT FROM AUTHOR]

The alarming human health effects induced by endocrine disruptors (ED) have raised the attention of public opinion and policy makers leading worldwide to regulations that are continuously improved to reduce exposure to them. However, decreasing the exposure levels is challenging because EDs are ubiquitous and exposure occurs through multiple routes. The main exposure route is considered ingestion, but, recently, the inhalation has been hypothesized as an important additional route. To explore this scenario, some authors applied bioassays to assess the endocrine activity of air. This review summarizes for the first time the applied methods and the obtained evidences about the in vitro endocrine activity of airborne particulate matter (PM) collected outdoor. Among the bioassay endpoints, (anti)oestrogenic and (anti)androgenic activities were selected because are the most studied endocrine activities. A total of 24 articles were ultimately included in this review. Despite evidences are still scarce, the results showed that PM can induce oestrogenic, antioestrogenic, androgenic and antiandrogenic effects, suggesting that PM has an endocrine disrupting potential that should be considered because it could represent a further source of exposure to EDs. Although it is difficult to estimate how much inhalation can contribute to the total burden of EDs, endocrine activity of PM may increase the human health risk. Finally, the results pointed out that the overall endocrine activity is difficult to predict from the concentrations of individual pollutants, so the assessment using bioassays could be a valuable additional tool to quantify the health risk posed by EDs in air. [Display omitted] • Endocrine activity of outdoor particulate matter assessed with in vitro assays. • PM can induce oestrogenic, antioestrogenic, androgenic and antiandrogenic effects. • Inhalation of PM could increase exposure to endocrine disruptors. • Endocrine activity is difficult to predict using only pollutant concentrations. • Bioassays useful to quantify health risk posed by endocrine disruptors on PM. [ABSTRACT FROM AUTHOR]

The rapid growth of population and economy has led to an increase in urban air pollutants, greenhouse gases, energy shortages, environmental degradation, and species extinction, all of which affect ecosystems, biodiversity, and human health. Atmospheric pollution sources are divided into direct and indirect pollutants. Through analysis of the sources of pollutants, the self-functioning of different plants can be utilized to purify the air quality more effectively. Here, we explore the absorption of greenhouse gases and particulate matter in cities as well as the reduction of urban temperatures by plants based on international scientific literature on plant air pollution mitigation, according to the adsorption, dust retention, and transpiration functions of plants. At the same time, it can also reduce the occurrence of extreme weather. It is necessary to select suitable tree species for planting according to different plant functions and environmental needs. In the context of tight urban land use, the combination of vertical greening and urban architecture, through the rational use of plants, has comprehensively addressed urban air pollution. In the future, in urban construction, attention should be paid to the use of heavy plants and the protection and development of green spaces. Our review provides necessary references for future urban planning and research. [Display omitted] • Progress of plant remediation of urban air pollution. • Urban air pollution sources do harm to ecological environment and human health. • Plants can absorb greenhouse gases and particulate matter and improve air quality. • Provide a new perspective for urban air governance. [ABSTRACT FROM AUTHOR]

This study focuses on modeling air quality with an adaptive utilization of spatio-temporal information from multiple air quality monitoring stations under a multi-scale framework. To this end, it is necessary to consider different strategies to combine different methods to decompose the given series and to fuse multi-site information. Based on a systematic comparative analysis, we propose a novel multi-scale and multi-site modeling method named the multivariate empirical mode decomposition and spatial cosine-attention-based long short-term memory (MEMD-SCA-LSTM). The MEMD-SCA-LSTM first employs MEMD to decompose the multi-site air quality series into the scale-aligned components and then models the components at different scales. The high-frequency components are modeled by a novel SCA-LSTM, which employs LSTM with residual blocks to extract the temporal information and utilizes an attention mechanism based on the cosine similarity to adaptively extract interactions among different sites. Other relatively regular components are modeled by the LSTM. Empirical study on PM 2.5 in Hong Kong has demonstrated the effectiveness of fusing multi-site information using the spatial attention (SA) mechanism under the multi-scale framework with MEMD. The proposed MEMD-SCA-LSTM can improve the one-day ahead modeling performance with the mean absolute error and the root mean square error reduced over 10%, compared to the baseline modeling methods. For the two-day and three-day ahead performance, the MEMD-SCA-LSTM is still the best one. Furthermore, by visualizing the attention weights, we illustrate that our proposed SCA-LSTM can overcome some limitations of the traditional attention mechanisms and that the attention weights exhibit more informative patterns which could be used to analysis the transport of air pollutant between sites. The proposed modeling method is a general method, which is feasible and applicable to other pollutants in other cities or regions. [Display omitted] • A multi-site and multi-scale modeling method for air quality is proposed. • This modeling method is based on MEMD and attention mechanism. • MEMD is more suitable to reveal the coupled spatial information among sites. • LSTM with spatial cosine attention can better model the high frequency components. • Attention weights can mine more informative patterns of interactions among sites. [ABSTRACT FROM AUTHOR]

Various physiological and biochemical responses of two good biomonitor plant species i.e. Datura alba and Ricinus communis were studied along two roads in the Punjab, Pakistan. Chlorophyll a , b , total chlorophylls, carotenoids, total free amino acids, total soluble proteins, total antioxidant activity, stomatal conductance, photosynthetic rate, internal CO 2 concentration, transpiration rate, and water use efficiency of D. alba and R. communis were examined at different sites along both roads. Photosynthetic rate of both plant species was found to be affected. Reduced transpiration rate and stomatal conductance were also noted. However, elevated internal CO 2 concentration and water use efficiency were recorded. Total soluble proteins got reduced, but, we found a tremendous increase in total antioxidant activity and total free amino acids in both plant species. D. alba was found to be more affected by the adverse effects of roadside air borne pollutants. Although R. communis was also affected but it showed minimal variation in all parameters compared to the control. Hence, our results suggest that R. communis is more resistant to urban roadside air pollution compared to D. alba and would be a good choice as phytoremediator of traffic borne pollutants, whereas, D. alba could be a better biomonitoring plant. • Vehicle exhaust is the biggest sources of air pollution these days. • Biological effects of vehicle pollution can be assessed by the use of biomonitoring plants. • R. communis and D. alba are two effective biomonitoring plants. • They responded differently to vehicle exhaust pollution at roadsides. • R. communis could be a good phytoremediator, while, D. alba can be used as a bioindicator plant at roadsides. [ABSTRACT FROM AUTHOR]

In this work, we develop a model able to predict the equilibrium separation of gases due to differences in their molecular weights and the action of gravity. The separation of H, He, O, and N 2 with altitude is a characteristic phenomenon of the heterosphere. The model is able to qualitatively recreate the compositional profile of the whole heterosphere from a single composition measurement. The model is applied to the separation of air components and pollutants by empty wells drilled on the planet surface. It predicts that the separation of gases would be possible in wells deep enough under equilibrium. The high molecular weight of some anthropogenic pollutants (SO 2 , O 3 , NO 2 , CO 2 , etc.) would facilitate their segregation along shorter distances compared to those involved in the heterosphere. The simulations indicate that deep wells could concentrate some air components and pollutants by orders of magnitude over the levels at the Earth's surface without external energy input. For instance, argon molar fractions of >40% and >60% could be achievable at 44 km and 55 km depth, respectively. Finally, we discuss the feasibility of gravitational separation as a potential pollution abatement technology. Image 1 • A simple yet powerful equilibrium model of gas barodiffusion is proposed. • The model is used to predict gas profiles in the atmosphere and in empty wells. • The potential of empty wells to separate gases is predicted for the first time. • Heavy gases would segregate along shorter distances inside wells. [ABSTRACT FROM AUTHOR]

Tropospheric ozone ( O 3 ) time series have been converted into complex networks through the recent so-called Visibility Graph (VG), using the data from air quality stations located in the western part of Andalusia (Spain). The aim is to apply this novel method to differentiate the behavior between rural and urban regions when it comes to the ozone dynamics. To do so, some centrality parameters of the resulting complex networks have been investigated: the degree, betweenness and shortest path. Some of them are expected to corroborate previous works in order to support the use of this technique; while others to supply new information. Results coincide when describing the difference that tropospheric ozone exhibits seasonally and geographically. It is seen that ozone behavior is fractal, in accordance to previous works. Also, it has been demonstrated that this methodology is able to characterize the divergence encountered between measurements in urban environments and countryside. In addition to that, the promising outcomes of this technique support the use of complex networks for the study of air pollutants dynamics. Particularly, new nuances are offered such as the identification and description of singularities in the signal. Image 1 [ABSTRACT FROM AUTHOR]

Exposure to air pollution has been associated with a wide range of adverse health outcomes. However, the available evidence on the impact of air pollution exposures on liver enzymes is still scarce. The aim of the present study was to assess the relationship between exposure to ambient PM 1 , PM 2.5 and PM 10 during pregnancy and serum level of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and gamma-glutamyl transferase (GGT) in cord blood samples of newborns. Moreover, the association between total street length in different buffers and distance to major roads at the maternal residential address and liver enzymes were investigated. This cross-sectional study was based on data from a sample of 150 newborns, from Sabzevar, Iran. Land use regression models were used to estimate concentrations of air pollutants at home during pregnancy. Multiple linear regression was developed to estimate association of AST, ALT, ALP and GGT with air pollution controlled for relevant covariates. In fully adjusted models, increase in PM 1 and PM 2.5 as well as PM 10 were associated with higher levels of AST, ALT and GGT. Moreover, there was a significant association between total street length in a 100 m buffer at residential address with AST, ALT and GGT. Each meter increase in distance to major roads was associated with −0.017 (95% confidence interval (CI): -0.028, −0.006) decrease in AST. Overall, our findings were supportive for association between PMs exposure during pregnancy and increase in liver enzymes in newborns. Further studies are needed to confirm these findings in other settings and populations. • Maternal exposure to PMs and change in fetal liver enzymes were investigated. • LUR models were applied to estimate PM1, PM2.5 and PM10 at residential address. • Increase in PM 1 , PM 2.5 and PM 10 was associated with higher level of AST, ALT and GGT. [ABSTRACT FROM AUTHOR]

On July 1st, 2015, Hong Kong became the first city in Asia to implement a policy regulating sulfur dioxide (SO 2) in shipping emissions. We conducted an accountability study assessing the improvement in ambient air quality and estimating the effect on health outcomes of the policy. We used interrupted time series (ITS) with segmented regression to identify any change in ambient concentrations of SO 2 in contrast to other ambient pollutants (particulate matter <10 μm in diameter (PM 10), nitrogen dioxide (NO 2) and ozone (O 3)) at 10 monitoring stations in Hong Kong from 2010 to 2017. We validated these findings using cumulative sum control (CUSUM) charts. We used a validated risk assessment model to estimate effects of changes in air quality on death for natural causes, cardiovascular and respiratory diseases. Mean monthly concentrations of SO 2 fell abruptly at the monitoring station closest to the main shipping port (Kwai Chung (KC)) by −10.0 μgm3 p-value = 0.0004, but not elsewhere. No such changes were evident for the other pollutants (PM 10 , NO 2 , O 3). CUSUM charts confirmed a change in July 2015. Estimated deaths avoided per year as a result of the policy were 379, 72, 30 for all natural causes, respiratory and cardiovascular diseases respectively. Implementation of the shipping emission policy in Hong Kong successfully reduced ambient SO 2 , with the potential to reduce mortality. However, to gain full benefits, restrictions on shipping emissions need to be implemented throughout the region. Image 1 • Shipping emission policy resulted in a reduction in SO 2 at the main shipping port in Hong Kong by almost 50%. • Other benefits included a reduction in PM 10 by 20%. • The policy reduced air pollution related deaths. • Full benefits of the policy can only be accomplished if it is enforced regionally and not just in Hong Kong. [ABSTRACT FROM AUTHOR]

Abstract An open-system combustion chamber was designed and constructed for simulation of burning of various biomass types to estimate emission factors of pollutant gases, fine particulate matters and their composition to find out significant tracers. Rice straw (RS), maize residues (MR) and forest leaf litters (FLL) from mixed deciduous forest (MDF) and dry dipterocarp forest (DDF) were collected from various places in Northern Thailand based on land-use types. Approximately 1 kg of air-dried biomass sample was burned in the chamber, PM 2.5 were collected. CO 2 dominated during the flaming state while CO is predominant in the smoldering state. The highest EF PM2.5 was obtained from MDF burning (4.38 ± 2.99 g kg−1), while the lowest value was from MR burning (2.15 ± 0.95 g kg−1). Among water soluble ions, K+ (biomass burning (BB) tracer) was the most abundant species in PM 2.5 followed by Cl− and SO 4 2−. The average EF K + from the burning of agricultural biomass was significantly higher than the burning of FLL. Scatter plot of K+/SO 4 2− versus K+/Cl− can be used to distinguish between agricultural crop residues and FLL burning. Levoglucosan (BB tracer) was a dominant species among anhydrosugars and also a major component found in FLL burning. The ratios of levoglucosan/K+ and levoglucosan/mannosan obtained from forest and agricultural waste burnings were significantly different, therefore they can be used for BB source identification. Graphical abstract Image 1 Highlights • K+/SO 4 2− and K+/Cl− can identify agricultural residue and forest leaf litter burnings. • K+ is an abundant ion for agricultural residue burning particularly in rice straw. • K+, Cl− and NH 4 + are mainly from fertilizer and herbicide usage in crop plantation. • Levoglucosan is an abundant species for forest burning. • Agricultural residue burning provided low value of levo/K+, but high levo/mannosan. [ABSTRACT FROM AUTHOR]

Abstract Particulate matter (PM) exposure poses many adverse effects on human health. However, it is challenging to clearly differentiate between the contributions of individual pollutants on toxicity from complex mixtures of ambient air pollutants. The aim of this study is to generate aerosols constituted by silica nanoparticles (NPs) and bisulfate to serve as simulators of particle-associated high-sulfur air pollution. Then, the health impacts of sulfur dioxide were evaluated at the cellular level using an air-liquid interface (ALI) exposure chamber. BEAS-2B cells were exposed to either nano-silica or bisulfite aerosol individually or bisulfate-coated silica (SiO 2 -NH 2 @HSO 3) for 3 h using the ALI. The cellular toxicities were carefully compared based on the exposure dosages. The ALI exposure of SiO 2 NPs alone did not produce any apparent cytotoxicity in cells, but the aerosol exposure of SiO 2 -NH 2 @HSO 3 significantly decreased the cell viability and enhanced the production of cellular reactive oxygen species in a dose-dependent manner. Consequently, the excessive oxidative stress resulted in mitochondrial damage as well as cellular apoptosis. ALI exposure can possibly reflect the realistic physiological exposure condition of the human respiratory system. As a derivative of the sulfur dioxide component of air pollution, sulfate exacerbates the toxic effects of inhalable PMs. This result may be due to the large surface area of the nanoparticles, with the possibility of carrying more sulfite to the target cells during aerosol exposure. The sulfate levels offer a meaningful complement to the present PM 2.5 index of air pollution for achieving better human health protection. Graphical abstract Image 1 Highlights • Air-liquid interface exposure was used to evaluate the cytotoxicity of pollutants. • The SiO 2 -NH 2 nanoparticles with carrying HSO 3 − simulate atmospheric pollutants. • The ratio of HSO 3 − bounded on the silica represents for different pollution level of sulfate in actual environment. • Sulfate exacerbates the toxic effects of the inhalable particular matters. • SiO 2 -NH 2 @HSO 3 induces apoptosis by activating mitochondrial stress pathway. [ABSTRACT FROM AUTHOR]

Abstract The North China Plain and the Yangtze River Delta are the two of the most heavily polluted regions in China. Observational studies revealed that 'explosive' PM 2.5 mass concentration growths frequently occurred in the two regions. This study analyzed all the PM 2.5 mass concentration growth processes from clean condition (i.e., <35 μg m−3) to heavy pollution condition (i.e., >150 μg m−3) in Beijing (BJ) and Shanghai (SH), two representative cities of the two regions, using hourly monitored PM 2.5 concentrations during 2013–2016. 173 and 76 growth processes were identified in BJ and SH, respectively. PM 2.5 rising rates (PMRR) and dynamic growth durations were calculated to illustrate the characteristics of the growth processes. Hourly particulate chemical composition data and meteorological data in BJ and SH were further analyzed. The 4-year averaged PMRR of PM 2.5 total mass were similarly of 7.11 ± 9.82 μg m−3 h−1 in BJ and 6.71 ± 6.89 μg m−3 h−1 in SH. A decreasing trend was found for the PM 2.5 growth processes in two cities from 2013 to 2016, reflecting the effectiveness of emission controls implemented in the past years. The contributions of particulate components to the PM 2.5 total mass growth were different in BJ and SH. Average PMRR value of PM 1 organic aerosols (OA), SO 4 2−, NO 3 −, and NH 4 + in BJ was 1.90, 0.95, 0.82, and 0.53 μg m−3 h−1, respectively. Average PMRR of PM 2.5 OA, SO 4 2−, NO 3 −, and NH 4 + in SH was 1.70, 1.18, 1.99 and 1.14 μg m−3 h−1, respectively. Based on the contributions of different components, the PM 2.5 mass concentration growth processes in BJ and SH were proposed to be classified into 'other components-dominant growth processes', 'all components-contributing growth processes', 'one or more explosive secondary components-dominant growth processes', and 'mixed-factor growth processes'. Potential source contribution function analysis and the meteorological condition analysis showed that source origins and prevailing wind for the two cities during different categories of growth processes had substantial difference. The important source areas included Hebei and Shandong for BJ, and Jiangsu and Anhui for SH. The dominant wind directions during growth processes were northeast, south and southwest in BJ, and were west to north in SH. The results suggested the contributing components, the prevailing wind conditions, and the formation processes were substantially different in the two cities, despite the similar PMRR of PM 2.5 total mass during the growth processes between BJ and SH. Future research is needed to study the detailed formation mechanisms of the different PM 2.5 mass concentration growth processes in the two cities. Highlights • PM 2.5 growth processes during 2013–2016 in the NCP and YRD region of China were investigated. • 4-year averaged PMRRs of PM 2.5 total mass are 7.07 ± 8.42 μg m−3 h−1 in BJ and 6.60 ± 5.99 μg m−3 h−1 in SH. • Organic aerosol is more important in BJ, while nitrate is more important in SH. • The PM2.5 growth processes in BJ and SH are proposed to be classified into four general categories. [ABSTRACT FROM AUTHOR]

Abstract Biodiesel or renewable diesel fuels are alternative fuels produced from vegetable oil and animal tallow that are being considered to help reduce the use of petroleum-based fuels and emissions of air pollutants including greenhouse gases. Here, we analyzed the gene expression of inflammatory marker responses and the cytochrome P450 1A1 (CYP1A1) enzyme after exposure to diesel and biodiesel emission samples generated from an in-use heavy-duty diesel vehicle. Particulate emission samples from petroleum-based California Air Resource Board (CARB)-certified ultralow sulfur diesel (CARB ULSD), biodiesel, and renewable hydro-treated diesel all induced inflammatory markers such as cyclooxygenase-2 (COX)-2 and interleukin (IL)-8 in human U937-derived macrophages and the expression of the xenobiotic metabolizing enzyme CYP1A1. Furthermore, the results indicate that the particle emissions from CARB ULSD and the alternative diesel fuel blends activate the aryl hydrocarbon receptor (AhR) and induce CYP1A1 in a dose- and AhR-dependent manner which was supported by the AhR luciferase reporter assay and gel shift analysis. Based on a per mile emissions with the model year 2000 heavy duty vehicle tested, the effects of the alternative diesel fuel blends emissions on the expression on inflammatory markers like IL-8 and COX-2 tend to be lower than emission samples derived from CARB ULSD fuel. The results will help to assess the potential benefits and toxicity from biofuel use as alternative fuels in modern technology diesel engines. Highlights • Biodiesel or renewable diesel fuels induce inflammatory markers in macrophages. • Diesel and biodiesel emission samples induce cytochrome P450 1A1. • Emissions samples from diesel and the alternative diesel fuel blends activate the aryl hydrocarbon receptor. • Effects of the alternative diesel fuel blends emissions on the expression on inflammatory markers tend to be lower than emission samples derived from California ultra-low sulphur diesel fuel. [ABSTRACT FROM AUTHOR]

Abstract People have been suffering from air pollution for a decade in China, especially from PM 2.5 (particulate matter with a diameter of less than 2.5 μm). Accurate prediction of air quality has great practical significance. In this paper, we propose a data-driven model, called as long short-term memory - fully connected (LSTM-FC) neural network, to predict PM 2.5 contamination of a specific air quality monitoring station over 48 h using historical air quality data, meteorological data, weather forecast data, and the day of the week. Our predictive model consists of two components: (1) Using a long short-term memory (LSTM)-based temporal simulator to model the local variation of PM 2.5 contamination and (2) Using a neural network-based spatial combinatory to capture spatial dependencies between the PM 2.5 contamination of central station and that of neighbor stations. We evaluate our model on a dataset containing records of 36 air quality monitoring stations in Beijing from 2014/05/01 to 2015/04/30 and compare it with artificial neural network (ANN) and long short-term memory (LSTM) models on the same dataset. The results show that our LSTM-FC neural network model gives a better predictive performance. Highlights • The LSTM-FC neural network can give an accurate prediction of urban PM 2.5 contamination over the next 48 hours. • The LSTM-FC neural network can handle the long-range dependence of PM 2.5 contamination. • The LSTM-FC use a fully connected neural network to combine the spatial information of surrounding stations. [ABSTRACT FROM AUTHOR]

Abstract Fuel combustion conditions and atmospheric aging processes can affect the physicochemical properties of soot particles, which further change the oxidative potential (OP) of soot. In this study, we generated two soot samples under higher and lower air/fuel ratio (A/F) conditions, and further treated them with ozone (O 3) at a level similar to that in the polluted atmosphere. The physicochemical properties and OP values (measured by dithiothreitol (DTT) assay, OPDTT) of fresh and ozonised soot samples were compared to investigate the influences of A/F and O 3 aging. Both A/F and O 3 aging significantly affected soot physicochemical properties and OPDTT values. Lower A/F was favourable for generating soot particles containing more polycyclic aromatic hydrocarbon (PAH), water-soluble organic carbon (WSOC), and light-absorbing organics, but fewer oxygen-containing groups. After O 3 aging, a decline in PAHs and increase in oxygen-containing groups and WSOC were observed in both aged soot samples. In addition, both lower A/F and O 3 aging enhanced soot OPDTT values. Soot generated under lower A/F was more sensitive to O 3 aging, after which there was a significantly greater change in physicochemical characteristics, in turn contributing substantially to the greater OP increase observed in low-A/F soot. Graphical abstract Image 1 Highlights • Both A/F and O 3 aging influenced the physicochemical properties of soot. • Lower A/F soot contained more PAHs and WSOC, but less oxygen-containing groups. • This study is the first to report the effects of A/F on the OPDTT values of fresh and ozonised soot. • Aged soot had higher OP and contained fewer PAHs and more oxygen-containing organics. • O 3 oxidation was more potent in L-soot than in H-soot. [ABSTRACT FROM AUTHOR]

Abstract Biomarkers are promising indicators to evaluate human exposure to air pollutants and to predict the health outcomes. Area of Airway macrophages that is occupied by Black Carbon could be used as a biomarker of personal long term exposure to traffic related air pollution. Association of airway macrophages carbon load with weighted average distance and environmental and subject-specific behavior are considered in this study. Sputum samples were taken from 160 healthy adult women and airway macrophages carbon load (AMCL) were determined in 93 subjects, which represent a success rate of 62% in sputum induction. Nearest distance of the subjects to major roads and average weighted distance were calculated for each subject. A questionnaire was field according to general and behavioral characteristics of the participants. There was not any significant difference (P-value >0.05) between induced and non-induced subjects. Subjects with indoor kitchen without separation wall, passive smokers and those with longer presence time in high traffic streets showed higher carbon area. Weighted average distance had a better association (β = −0.186, 95%CI: −0.139, −0.230, P-value = 0.00) with AMCL than nearest distance to major roads (β = −0.155, 95%CI: −0.109, −0.201, P-value = 0.19). Association of Weighted average distance with AMCL was interrupted in subjects with a garage connected to house environment, those with IK kitchen, those with a hood above the stove and passive smokers. The findings indicated that more generation and distribution of indoor air pollutants can completely enhance the internal exposure and indoor pollution has the same importance as outdoor pollution. Highlights • Airway macrophages are used as a biomarker of internal exposure. • Better association of weighted average distance with AMCL than the nearest distance. • More generation and distribution of indoor air pollutants can completely enhance the internal exposure. [ABSTRACT FROM AUTHOR]

Abstract Sulfur dioxide (SO 2) ranks as a major air pollutant and is likely to generate acid rain. When molecular oxygen is the oxygen source, the regular surfaces of gibbsite (one of the most abundant mineral dusts) show no reactivity for SO 2 conversions to H 2 SO 4 , while the partially dehydrated (100) surface with coordination-unsaturated Al sites becomes catalytically effective. Because of the easy availability of molecular oxygen, results manifest that acid rain can form under all atmospheric conditions and may account for the high conversion ratio of atmospheric SO 2. The (100) and (001) surfaces show divergent catalytic effects, and hydrolysis is always the rate-limiting step. Path A (hydrolysis and then oxidation) is preferred for (100) surface, whereas a third path with obviously lower activation barriers is presented for (001) surface, which is non-existent for (100) surface. Atomic oxygen originating from the dissociation of molecular oxygen is catalytically active for (100) surface, while the active site of (001) surface fails to be recovered, suggesting that SO 2 conversions over gibbsite surfaces are facet-controlled. This work also offers an environmentally friendly route for production of H 2 SO 4 (one of the essential compounds in chemical industry), directly using molecular oxygen as the oxygen source. Graphical abstract Image 1 Highlights • Molecular oxygen can react with atmospheric SO 2 to form acid rain. • Catalytic mechanisms for SO 2 conversions by mineral dusts have been posed. • Coordination-unsaturated Al sites are critical to the catalytic effects of gibbsite. • Catalytic conversions of SO 2 to H 2 SO 4 over gibbsite are facet-controlled. • An environmentally friendly route for production of H 2 SO 4 is also provided. [ABSTRACT FROM AUTHOR]

Abstract Concentrations and temporal variations of priority polycyclic aromatic hydrocarbons (PAHs) in the air from a suburban area of Dalian, China were investigated for a 1-year period to assess their sources and potential correlations with six criteria air pollutants and meteorological parameters. The total concentrations of PAHs were in the range of 4.32–112.2 ng/m3 (Mean = 52.37 ± 23.99 ng/m3). Seasonality was discovered with the PAHs following an order of winter > spring > summer > autumn. The impacts of meteorological parameters on PAH levels were season-dependent. High temperature may increase the air concentrations of 4-ring PAHs during the non-heating period, whereas high relative humidity may raise the concentrations of 3- and 4-ring PAHs during the heating period. Correlations of PAHs with criteria air pollutants, such as SO 2 , NO 2 , and O 3 , indicated that both fossil fuel combustion and photochemical oxidation influenced the air concentrations of PAHs. According to the source apportionment by diagnostic ratios and PMF model, coal combustion and traffic emission were estimated to be the main sources of PAHs in Dalian, followed by petroleum release and biomass burning. It was worth noting that the contribution of coal combustion to the PAH burdens increased from 26% to 45% due to the emission from domestic heating in winter. This extra emission needs a continuous concern in the future. Graphical abstract Image 1 Highlights • Correlations of gaseous PAHs with six criteria air pollutants were estimated. • Coal combustion and traffic emission were the main sources of PAHs in Dalian. • Contribution of coal combustion to PAHs increased 19% in winter due to coal heating. [ABSTRACT FROM AUTHOR]

On 6 February 2023, Türkiye was hit by two earthquakes with 7.5 (Eq2) and 7.8 (Eq1) magnitudes. In this study, the hourly ground-level air pollutant concentrations measured in the earthquake areas were examined in detail. In addition, the remote sensing retrievals of CO, NO 2 , SO 2 and CH 4 from TROPOMI instrument were also processed and investigated. The hourly mean PM 2.5 and CO increased at four stations close to the epicentre several hours prior to the earthquake. The abrupt increase in CO is likely, but PM 2.5 is probably related to the degassing activities in the faults. At the day of the earthquake, a significant TROPOMI NO 2 increase and a different spatial distribution over the region are observed. This increase coincides with the Eq2 (20 min prior) and a distinctive spatial distribution was observed on that day, indicating this signal can be associated with the earthquake or another process affected by the earthquake. On the other hand, TROPOMI CO indicated a significantly different pattern from NO 2 with lowest levels around or prior to the earthquakes, and increased levels afterwards. Limited data from TROPOMI was available for CH 4 and SO 2 due to meteorological conditions and data quality over the region to draw any conclusive findings. According to the results, it may be helpful to perform special Earth-based observations of NO 2 , CO and counts of nanoparticles in the ground-based atmosphere near fault lines in seismically active belts. In addition, anomalies can also be monitored via available satellite retrievals, especially in regions with active fault lines. [Display omitted] • A steady increase and different diurnal changes of PM 2.5 near the epicenter before the earthquake. • A significant increase in ground-level CO near the epicenter before the earthquake. • A different spatial NO 2 distribution with high levels over the region just before the earthquake. [ABSTRACT FROM AUTHOR]