Atmospheric Pollution Research Articles

Seasonal trend analysis and influence of meteorological factors on the concentration of atmospheric pollutants in an urban area

Introduction: Air pollution is a growing concern in Greater Noida, Uttar Pradesh, where meteorological factors play a major role. As urbanization accelerates, the region has not yet thoroughly examined the impact of factors like temperature, humidity, wind direction, and speed on pollutants like Particulate Matters (PM2.5, PM10), Nitrogen dioxide (NO2), and Sulfur dioxide (SO2) Materials and methods: To explore this issue, a 12-month study (January to December 2023) was conducted to analyze the relationships between these meteorological factors and pollutant levels. In the present study, pollutant movement was tracked over time. Pearson correlation was used to correlate air pollution concentrations with weather conditions. Results: The study revealed that the average concentrations of PM , PM , 10 2.5 and NO2 were 912.54 µg/m³, 257.42 µg/m³, and 65.98 µg/m³, respectively. In contrast, SO2 had an average concentration of 26.85 µg/m³. Conclusion: The study indicates that particulate matter and temperature are strongly negatively correlated, while wind speed shows a weak positive correlation with particulate matter. Pollution levels and relative humidity also display a negative correlation, as do particulate matter concentrations and humidity. However, gaseous pollutants exhibit little to no significant correlation with these weather conditions

A Review of Laboratory Studies on the Heterogeneous Chemistry of NO2: Mechanisms and Uptake Kinetics.

NO2 is a significant primary atmospheric pollutant that plays a key role in atmospheric chemistry. It serves as a crucial precursor to photochemical smog, acid rain, and secondary particulate matter and is instrumental in determining the atmospheric oxidation capacity. In this review, we focus on the heterogeneous chemistry of NO2, which has been demonstrated to significantly influence the sources and sinks of various nitrogen-containing species through field measurements and model simulations. We provide a comprehensive summary of laboratory studies investigating the reaction mechanisms and uptake kinetics of NO2 in heterogeneous reactions. NO2 can undergo disproportionation reactions on atmospheric particles. For instance, it may hydrolyze on wetted surfaces to form HONO and HNO3, produce nitrate and NO on mineral dust, or generate nitrate and NOCl on sea salt. Additionally, NO2 can be reduced to HONO on soot and Fe-bearing minerals or photocatalytically reduced to HONO and NO on photosensitive components. Furthermore, NO2 can be photo-oxidized to nitrate or N2O5 on illuminated TiO2. In addition, the synergistic effect of the heterogeneous reactions between NO2 and SO2 is discussed. The uptake coefficients of NO2 on typical particles and the factors influencing these coefficients are also summarized. Finally, based on the current insufficient understanding of heterogeneous reactions of NO2, we propose prospects for future research.

The establishment of blue-sky index: how to quantify the aerosol optical impacts on sky color

Abstract Color of the sky serves as a direct indicator of haze, while also exerting substantial influence on human physiological and psychological well-being, as well as the overall environmental scenery. However, quantifying color changes is quite challenging. This research develops a quantitative approach for evaluating the influence of atmospheric aerosol pollution on the appearance of the sky. We first calculated the influence of atmospheric aerosols on the sky’s diffuse radiation, which is the source of sky color. Then, we mapped the diffuse radiation onto a perceptually uniform color space to quantify alterations in sky color. The results reveal that the relationship between aerosol concentration and sky color change follows a logarithmic-like distribution: the higher the concentration, the weaker the change in sky color per unit increase in aerosol concentration. Consequently, during the early phases of air pollution control implementation, there may be minimal observable changes in the color of the sky. However, as these measures are further enforced, a discernible bluing effect on the sky will become evident. Based on the quantification of the change of sky color, a blue-sky index (BSI) was established. We find that concurrent with improvements in air quality resulting from emission reduction measures, the BSI has significantly decreased in recent years in China. This trend indicates an increase in the frequency of blue-sky occurrences.

Biomagnetic monitoring of urban atmospheric pollution: A review of magnetic signatures from different types of plants.

Biomagnetic monitoring has rapidly emerged as a valuable tool in urban atmospheric pollution (UAP) assessment due to its high spatial resolution, complementing traditional monitoring systems. This review systematically elucidates the principles of plant dust retention and the factors influencing it, while also reviewing the advancements in global research on UAP monitoring through the magnetic properties of various plant species. We provide a comprehensive analysis of the current applications of biomagnetic monitoring in UAP and identify critical challenges, including species-specific monitoring discrepancies, complex pollution sources, and non-standardized sample preparation methods. Additionally, we propose future research directions to address these challenges and enhance the efficacy of biomagnetic monitoring in UAP.

The Relationship between Noise Pollution and Depression and Implications for Healthy Aging: A Spatial Analysis Using Routinely Collected Primary Care Data.

Environmental noise is a significant public health concern, ranking among the top environmental risks to citizens' health and quality of life. Despite extensive research on atmospheric pollution's impact on mental health, spatial studies on noise pollution effects are lacking. This study fills this gap by exploring the association between noise pollution and depression in England, with a focus on localised patterns based on area deprivation. Depression prevalence, defined as the percentage of patients with a recorded depression diagnosis, was calculated for small areas within Cheshire and Merseyside ICS using the Quality and Outcomes Framework Indicators dataset for 2019. Strategic noise mapping for rail and road noise (Lden) was used to measure 24-h annual average noise levels, with adjustments for evening and night periods. The English Index of Multiple Deprivation (IMD) was employed to represent neighborhood deprivation. Geographically weighted regression and generalised structural equation spatial modeling (GSESM) assessed the relationships between transportation noise, depression prevalence, and IMD at the Lower Super Output Area level. The study found that while transportation noise had a low direct effect on depression levels, it significantly mediated other factors associated with depression. Notably, GSESM showed that health deprivation and disability were strongly linked (0.62) to depression through the indirect effect of noise, especially where transportation noise exceeds 55dB on a 24-h basis. Understanding these variations is crucial for developing noise mitigation strategies. This research offers new insights into noise, deprivation, and mental health, supporting targeted interventions to improve quality of life and address health inequalities.

Titanium Dioxide and Photocatalytic CO2 Reduction: A Detailed Review of the Current Status and Future Prospects

A significant amount of carbon dioxide is released into the atmosphere as a result of the extensive usage of fossil fuels. The photocatalytic reduction and conversion of CO2 under visible light into alternative renewable solar fuels or other oxygenated products (methane, formaldehyde, methanol, and formic acid) are practical and efficient methods for reducing atmospheric carbon pollution. Functional materials containing titanium dioxide (TiO2) have attracted significant interest for the photocatalytic reduction of CO2. In this direction, many studies have been conducted in recent years, especially on solar energy harvesting and the charge separation, adsorption, activation, and reduction of CO2 on enhanced TiO2. Recent studies have shown that brookite TiO2 (BT) was the most active photocatalyst, followed by rutile and anatase. Therefore, this study aims to review in detail the recent advances in the development of selective and active catalysts for photocatalytic CO2 reduction using titanium dioxide with a brookite structure. This review evaluates the most common methods for obtaining BT. It discusses various engineered strategies, including doping with metallic or non-metallic heteroatoms, addition of a co-catalyst, formation of heterojunctions, and other algorithms to improve the CO2 reduction mechanism. The influence of another phase and crystal facets on the photocatalytic CO2 reduction reaction are discussed in detail. The problems associated with BT-based photocatalysts, namely, their modest visible-light absorption, slow interfacial charge separation, and poor surface catalytic dynamics, are further discussed, along with possible solutions. To stimulate additional research in this field, the difficulties and potential advantages of photocatalytic CO2 conversion methods are discussed.

Monitoring the trends of carbon monoxide and tropospheric formaldehyde in Edo State using Sentinel-5P and Google Earth Engine from 2018 to 2023.

This research was carried out to assess the concentrations of carbon monoxide (CO) and formaldehyde (HCHO) in Edo State, Southern Nigeria, using remote sensing data. A secondary data collection method was used for the assessment, and the levels of CO and HCHO were extracted annually from Google Earth Engine using information from Sentinel-5-P satellite data (COPERNISCUS/S5P/NRTI/L3_) and processed using ArcMap, Google Earth Engine, and Microsoft Excel to determine the levels of CO and HCHO in the study area from 2018 to 2023. The geometry of the study location is highlighted, saved and run, and a raster imagery file of the study area is generated after the task has been completed with a 'projection and extent' in the Geographic Tagged Image File Format (.tiff) and downloaded from the Google Drive and saved into folders, imported into the ArcMap for data processing and Excel worksheet for analysis. The raster data were collected annually for each pollutant with the 'filterDate = year-01-01; year-12-31'. Results showed that the annual mean concentrations of CO ranged from '4.67 × 10-2mol/m2' to '5.34 × 10-2mol/m2'. The maximum concentration was found in the year 2018 and the minimum was found in the year 2023, a relatively high concentration of CO may lead to the formation of carboxyhaemoglobin which decreases the capacity of the blood to transport oxygen causing lung cancer, heart problems, respiratory conditions and damage to other organs. While the annual mean concentrations of HCHO ranged from '1.89 × 10-4mol/m2' to '2.18 × 10-4mol/m2', the maximum concentration was found in the year 2021 and the minimum was found in the year 2019, increasing concentration of HCHO may be due to biomass burning and the combustion of methane (CH4 gas), and can cause nasopharyngeal cancer in humans. Based on the result of this study, constant monitoring of the air quality and atmospheric pollutants to ensure early detection of a decrease or increase in the concentration of atmospheric pollutants, implementation of air pollution control policies, spatial data collection, air quality modelling, hotspot identification and source distribution using the geographic information system (GIS), promotion of cleaner technologies, including the use of low-emission vehicles and renewable energy sources, public awareness and education on the impact of atmospheric pollutants and the human contributions to the increasing production of atmospheric pollutants are highly recommended.

Thunderstorms and their Influence on Meteorology and Atmospheric Composition Over Southern Peninsular India

The study examines the long-term (2011-2023) analysis of thunderstorm and lightning activities and their impacts on local meteorology and air pollutants over Bengaluru. The diurnal thunderstorm events occur mainly in the late evening hours (1900–2100 IST) and on monthly maximum in May while minimum in January. Annually, Bengaluru experiences an average of 41 thunderstorms and 157 lightning strikes, both of which have shown a statistically significant upward trend at a 95% confidence level. The rate of increase is 3.41% per year for thunderstorms and 3.3% per year for lightning events. Local temperatures coupled with abundant moisture supply from the southwest/northeast monsoon creates a favourable condition for the initiation of thunderstorms over the region. This study also focused on the trend analysis of meteorological parameters and atmospheric compositions, a rising trend were found in rainfall (1.44 mm year–1), RH (0.74% year–1) & pressure (0.03 hPa year–1) whereas a slight declining trends in temperature (0.06 0C year-1) & wind speed (-0.02 ms-1 year–1). As the availability of heat and humidity are two main prerequisites for the occurrence of thunderstorm and hence the probability of severe thunderstorms may increase in future. The AOD, NO2 & O3 showed a significant increasing trend while no trend for SO2. The Pearson correlations showed the AOD, NO2 & SO2 concentrations are significant negatively correlated with wind speed but positively correlated with atmospheric pressure. A further study indicated a significant impact of thunderstorm on the air pollutants has also been quantified and it was observed that PM2.5 concentration gradually decreases after the commencement of thunderstorm while quick increase response (less than 1 hour) was observed in O3 and delay response (after 2:30 hours) in NO2 which may linked to lightning activities. The results reveal that thunderstorms can affect both the local meteorology as well as atmospheric pollutants and vice-versa from regional to global.

A Systematic Review on Atmospheric Ozone Pollution in a Typical Peninsula Region of North China: Formation Mechanism, Spatiotemporal Distribution, Source Apportionment, and Health and Ecological Effects

A Systematic Review on Atmospheric Ozone Pollution in a Typical Peninsula Region of North China: Formation Mechanism, Spatiotemporal Distribution, Source Apportionment, and Health and Ecological Effects

Emission Characteristics and Health Risk Assessment of Volatile Organic Compounds in Key Industries: A Case Study in the Central Plains of China

Volatile organic compounds (VOCs), the precursors of ozone and fine particulate matter, are one of the atmospheric pollutants harmful to human health. The emission characteristics of VOCs in Anyang, a typical industrial city in the Central Plains of China, are unclear. To determine the emission level and composition of local VOCs, this study conducted on-site sampling of 20 factories in eight key industries. A total of 105 VOC species in seven categories were observed. The concentration of total VOCs emitted from the eight industries in order from large to small was as follows: packaging and printing > pharmaceutical > paint manufacturing > industrial coating > chemical industry > metal smelting > furniture manufacturing > textile printing and dyeing. In addition to industrial coating, the total VOCs and their corresponding ozone formation potential of organized emissions in seven industries (1.44–87.64, 1.52–181.61 mg/m3) were higher than those of unorganized emissions (0.38–24.17, 0.38–125.55 mg/m3). The VOC emissions were concentrated in the central, south-central, and south-eastern parts of the city, mainly from the factories in the packaging and printing, pharmaceutical, paint, and coating industries. The furniture manufacturing (4.55 × 10−3) and pharmaceutical (1.66 × 10−3) industries in organized emissions were at high risk of carcinogenesis, while the pharmaceutical industry in unorganized emissions (3.61 × 10−4) was at moderate risk of carcinogenesis. Naphthalene was the main high-risk compound. In terms of non-carcinogenic risk, the packaging and printing industry in organized emissions (228.51) and the metal smelting industry in unorganized emissions (16.16) had the highest risk, and the main high-risk compound was ethyl acetate.

Nuclear Waste Tank Emission Contributions to Particle Size Distribution.

Pollutants from anthropogenic activities including industrial processes are ubiquitous to the environment. To understand the impact from industrial aerosol on climate and human health, industrial aerosol needs to be better characterized. In this study, particle number concentrations were used as a proxy for atmospheric pollutants, which include both particles and gases. Particle concentration and size distribution were measured using a scanning mobility particle sizer (SMPS) approximately 4.5 km from primary industrial areas at the Savannah River Site in Aiken, SC. Industrial areas include numerous nuclear waste storage and processing tanks. The SMPS data were divided into two groups depending on the wind direction measured onsite to categorize transport from the industrial area or from elsewhere. Industrial contributions were found to have a higher concentration of particles with sizes less than 200 nm, 859 ± 564 cm-3, in comparison to non-industrial attributed particles, 733 ± 495 cm-3 on average from March-July 2021. For sizes larger than 200 nm, industrial and non-industrial particles have a similar concentration, 89 ± 59 cm-3 and 99 ± 61 cm-3, with non-industrial concentrations being slightly larger. To confirm that industrial particles could travel to the sampling location, air dispersion modeling was completed for specific case studies during the sampling period. The atmospheric dispersion modeling results confirmed that particles released at the industrial areas reached the sampling location when the wind direction was favorable for transport from the industrial areas. The greater concentration of smaller-sized particles in industrial emissions has implications for typical particulate measurements (PM2.5), heath impacts, and climatological influences.

Atmospheric aggravation potential of a wastewater treatment plant concerning organochlorine pesticides, polychlorinated biphenyls, and polybrominated diphenyl ether emissions.

The pollution potential of a municipal wastewater treatment plant (WWTP) in Bursa, Türkiye, in terms of organochlorine pesticides (Σ22OCPs), polychlorinated biphenyls (Σ46PCBs), and polybrominated diphenyl ethers (Σ14PBDEs), was investigated in air samples. Concentrations were determined using polyurethane foam disk samplers at key processes, such as the aeration tank (AT) and settling chamber (SC) of the WWTP and the background area (BA) at an urban site. Atmospheric concentration levels of PBDEs at the SC are 1.3 times higher than at the AT site. PCBs concentration levels are listed as SC>BA>AT from high to low. The highest OCPs concentration levels were detected at the BA site while the lowest concentration levels were obtained for the SC site. Compared to organochlorine pollutants (PCBs and OCPs), PBDEs levels were higher by two orders of magnitude ranging from 0.2 to 54.3ng/g. While the presence of OCPs was not significant, an unusual abundance of mirex was observed. HCB, HCHs (excluding β-HCH), and p,p'-DDE resulting mainly from the settling tank indicate enhanced mass transfer from wastewater to air. Regarding PCBs, the level and detection frequency of dioxin-like PCBs (118, 123) in the aeration tank and the settling chamber were remarkable. The upper levels of PBDEs congeners 17, 85, 138, 153, and 154 resulting from the settling tank suggest an enhanced mass transfer from water to air as the source medium. Although the primary fate of trace organics in WWTPs is expected to be sorption to sludge, the present study has shown that WWTPs can be a non-negligible source of local atmospheric PCB and PBDE pollution. However, this study provides a snapshot of the levels of persistent organic pollutants and emissions, and there is no doubt that more detailed and long-term studies are needed.

NH3 release during the snow evaporation process in typical cities in Northeast China

NH3 is the most important alkaline gas in the atmosphere and functions as a precursor to secondary ammonium salts. Therefore, identifying its sources and quantifying its emissions is imperative. NH4+ represents a principal component of atmospheric particulate pollutants. As particulate matter acts as a condensation nucleus for wet deposition, the NH4+ concentrations in precipitation are typically elevated. During the evaporation process of wet deposition, NH4+ is likely to be re-emitted as a gas (NH3). In Northeast China, heavy and frequent snowfall occurs, making it crucial to elucidate the NH3 release flux and the factors influencing this release during the snow evaporation process in representative cities of this region. This study collected snow samples from five notable snowfall events in Changchun, Jilin Province that occurred from November 2023 to March 2024, to conduct indoor simulated evaporation experiments (among them, the actual phase changes of two snowfall events consisted mainly of evaporation, whereas those of the other three events consisted mainly of sublimation). The results indicated that during the snow evaporation process, the average ratio (R) of NH4+ re-emitted as NH3 was 39.28 ± 12.07%. The average release flux (F) was 1624.58 ± 2064.5 μg/m2, and the average release rate (V) was 361.33 ± 465.31 ng/(m2·s). Within the 100-m atmospheric boundary layer, the total NH3 flux that was released subsequently during the evaporation of all snowfall events in Changchun during the study period was 46.97 mg/m2. The average release flux for individual snowfall events was 688.66 μg/m2, which constituted approximately 2.44% of the NH3 concentration documented in the winter atmosphere of Changchun. During the snow evaporation or sublimation process, R was positively correlated with the environmental temperature (P < 0.05) and negatively correlated with both the environmental wind speed and snowfall amount (P < 0.05). Significant variations in R were observed across multiple functional areas, which were ranked in descending order as follows: commercial areas (R = 26.16%), residential areas (R = 22.01%), cultural and educational areas (R = 20.7%), and industrial areas (R = 18.01%). The influence of a snow-melting agent (NaCl) on the conversion rate of NH3 initially increased but then subsequently decreased as the dose increased. The lowest measured value (R = 22.02%) was 0 mg/L, whereas the peak measured value (R = 30.31%) was attained at a concentration of 200 mg/L. The findings of this research are important for illuminating the cycling process of NH3 in the atmosphere and for the comprehensive management of air quality.

Antibiotic resistance genes in the coastal atmosphere under varied weather conditions: distribution, influencing factors, and transmission mechanisms.

Antibiotic resistance genes (ARGs) have escalated to levels of concern worldwide as emerging environmental pollutants. Increasing evidence suggests that non-antibiotic antimicrobial substances expedite the spread of ARGs. However, the drivers and mechanisms involved in the generation and spread of ARGs in the atmosphere remain inadequately elucidated. Co-occurrence networks, mantel test analysis, and partial least squares path modeling were used to analyze the symbiotic relationships of ARGs with meteorological conditions, atmospheric pollutants, water-soluble inorganic ions, bacteria, mobile genetic elements (MGEs), antibacterial biocide and metal resistance genes, and to identify the direct drivers of ARGs. The types and abundance of ARGs exhibited different seasonal distribution. Specifically, the types exhibited a strong alignment with the diversity of air masses terrestrial sources, while the abundance displayed a significant positive correlation with both biocide resistance genes (BRGs) and metal resistance genes (MRGs). The contribution of bacterial communities and MGEs to the generation and spread of ARGs was constrained by the low levels of antibiotics in the atmosphere and the existence of "viral intermediates". Conversely, antibacterial biocides and metals influenced mutation rates, cellular SOS responses, and oxidative stress of bacteria, consequently facilitating the generation and spread of ARGs. Moreover, the co-selection among their derivatives, resistance genes, ensured a stable presence of ARGs. The research highlighted the significant impact of residual antimicrobial substances on both the generation and spread of ARGs. Elucidating the sources of aerosols and the co-selection mechanism linking with ARGs, BRGs, and MRGs were crucial for preserving the stability of ARGs in the atmosphere.

Contribution of dust emissions from farmland to particulate matter concentrations in North China Plain: Integration of WRF-Chem and WEPS model.

Wind erosion from farmland is a significant contributor to atmospheric particulate matter, particularly PM10 (atmospheric particulate matter with an aerodynamic diameter≤10μm), in regions with intensive agricultural activities such as the North China Plain (NCP). However, the specific impact of farmland dust emissions on regional air quality remains underexplored. This study integrated the Wind Erosion Prediction System (WEPS) model with the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) to investigate the effect of agricultural dust emissions on PM10 concentrations in the NCP. Results indicated that wind erosion from agricultural fields in the NCP produced approximately 33.8×105 tons of PM10 annually. These emissions are predominantly concentrated during the winter months from October to next April, with the highest emissions occurring in Hebei, Henan, and Shandong provinces. Using scenario experiments with the WRF-Chem model, we further quantified the contribution of agricultural dust emissions to atmospheric PM10 concentrations. The findings revealed that farmland emissions contributed approximately 13% of atmospheric PM10 concentrations during winter months (January and December), underscoring the significant role of agricultural activities in regional air pollution. This study highlights the importance of including farmland wind erosion into chemical transport models to more accurately understand and mitigate the effects of agricultural activities on atmospheric pollution in agricultural regions worldwide.

Cement-MgO synergetic stabilized earth-straw mix: From material performance to building simulation

The production of traditional building materials like cement, lime, and common fired bricks consumes considerable energy and resources and causes atmospheric pollution. Thus, it’s essential to develop more eco-friendly materials for new construction. This research focuses on an earth-straw mixture stabilized hybridly with cement and active MgO. Three aspects scaled from material mix design and mechanical performance to building energy-saving simulation were examined. Three types of earth were considered, and the effects of MgO on M−ME were studied through compression strength, thermal conductivity and TGA tests. The best compressive strength achieved was 12.5 MPa (about 167 % of the standard for non-burned bricks and 125 % of the standard for minimum fired bricks), and the best thermal conductivity was 0.371 / (m·K) (only 44.2 % of that of common fired bricks). Using Design Builder software, energy load differences between M−ME and fired clay brick walls were simulated under given conditions, and the indoor thermal environment was analyzed. Based on the amount of wall earthwork used in the project, the M−ME wall (YC3) can theoretically capture approximately 12.80 kg/m3 of carbon from the air under natural curing conditions, mean while reducing heating energy consumption by 9.49 %. Overall, the utilization of soil and the presence of plant straw give M−ME advantages in carbon footprint and thermal performance over sintered and concrete bricks. As a new energy-saving material, M−ME significantly contributes to carbon reduction in production and operation phases, possessing great potential in decarbonizing the emission of the building sector.

Effects of Atmospheric Pollutants on Volatile-Mediated Insect Ecosystem Services.

Primary and secondary atmospheric pollutants, including carbon monoxide (CO), carbon dioxide (CO2), nitrogen oxides (NOx), ozone (O3), sulphur dioxide (SO2) and particulate matter (PM2.5/PM10) with associated heavy metals (HMs) and micro- and nanoplastics (MPs/NPs), have the potential to influence and alter interspecific interactions involving insects that are responsible for providing essential ecosystem services (ESs). Given that insects rely on olfactory cues for vital processes such as locating mates, food sources and oviposition sites, volatile organic compounds (VOCs) are of paramount importance in interactions involving insects. While gaseous pollutants reduce the lifespan of individual compounds that act as olfactory cues, gaseous and particulate pollutants can alter their biosynthesis and emission and exert a direct effect on the olfactory system of insects. Consequently, air pollutants can affect ecosystem functioning and the services regulated by plant-insect interactions. This review examines the already identified and potential impacts of air pollutants on different aspects of VOC-mediated plant-insect interactions underlying a range of insect ES. Furthermore, we investigate the potential susceptibility of insects to future environmental changes and the adaptive mechanisms they may employ to efficiently detect odours. The current body of knowledge on the effects of air pollutants on key interspecific interactions is biased towards and limited to a few pollinators, herbivores and parasitoids on model plants. There is a notable absence of research on decomposers and seed dispersers. With exception of O3 and NOx, the effects of some widespread and emerging environmental pollutants, such as secondary organic aerosols (SOAs), SO2, HMs, PM and MPs/NPs, remain largely unexplored. It is recommended that the identified knowledge gaps be addressed in future research, with the aim of designing effective mitigation strategies for the adverse effects in question and developing robust conservation frameworks.

Observational constraint on momentum flux-gradient relationships reduces modeling biases of PBL mixing of particles in urban area

Abstract The momentum flux-gradient relationships within the urban roughness sublayer deviate from the classical relationships proposed by the Monin-Obukhov similarity theory. Despite this discrepancy, prevailing atmospheric models persistently rely on these classical relationships, which were originally derived from natural, homogeneous surfaces. This practice may introduce significant errors when simulating urban atmospheric pollution. This study utilized meteorological parameters and turbulent fluxes obtained from field measurements in the urban roughness sublayer to re-establish momentum flux-gradient relationships. Compared to non-urban areas, the flux-gradient relationships in the urban environments exhibit significant deviations under stable conditions. Consequently, we revised a planetary boundary layer parameterization to incorporate new urban flux-gradient relationships. The revised scheme was implemented in the WRF-Chem model, and the simulation results demonstrated a marked reduction in modeling biases under stable conditions, particularly for relatively developed cities in Eastern China.

Spatial distribution and isotopic signatures of N and C in mosses across Europe.

The accumulation of nitrogen (N) in moss tissue has proven to be a reliable marker of increasing N deposition. However, this measurement does not offer additional data about the origin of pollution. In this respect, the analysis of the N isotopic ratios might be a helpful tool in providing supplementary information about the nature of the nitrogenous species in biomonitoring surveys. Furthermore, isotopic signatures have been extensively used in the study of N and carbon (C) biogeochemical cycles. The main purpose of this study was to determine N and C elemental contents and their stable isotopes in mosses to investigate atmospheric pollution patterns across Europe. We aimed at identifying the main N polluted areas and evaluating the potential use of isotopic signatures in the attribution of pollution sources at a regional scale. With these objectives in mind, >1300 samples from 15 countries from Europe, all of them participants of the ICP-Vegetation programme 2005-2006, were analyzed for their C and N contents and δ15N and δ13C. The results were compared to those derived from EMEP model, which provided modeled deposition and emission data, as well as to the predominant land uses at the sampling sites (based on CORINE Land Cover). This evaluation suggests that additional measurements of stable C and N isotopes in mosses could be a valuable tool in European environmental surveys. Such measurements not only provide useful information for identifying probable pollution sources but also enable the quantification of their contributions, serving as biological indicators of significant environmental processes. This study presents the first quantitative assessment of major atmospheric nitrogen (N) sources based on stable isotope analysis on a European scale, establishing a framework for evaluating historical changes in N across the region.

Analysis of cytotoxicity and genotoxicity of diesel exhaust PM2.5 generated from diesel and dual natural gas-diesel engines.

Diesel exhaust particles (DEPs) are atmospheric pollutants associated with adverse health effects. In response to their impact, natural gas (NG) has emerged as a promising alternative fuel due to its cleaner combustion. Although the cytotoxicity and genotoxicity of DEPs from diesel or NG engines have been extensively studied, the impact of dual natural gas-diesel systems remains unexplored. This study evaluated the toxicity of DEPs (PM2.5) emitted by an engine in diesel mode and dual natural gas-diesel mode on cellular parameters such as viability, apoptosis, oxidative stress, and DNA damage. The results showed that diesel DEPs reduced cell viability by up to 31 %, compared to a 19.2 % reduction with dual-mode DEPs. Apoptosis induction was also higher with diesel DEPs, with a 7 % increase compared to the dual mode. While dual-mode DEPs increased the production of reactive oxygen species (ROS) without causing DNA damage, diesel DEPs generated high ROS levels and measurable DNA damage. These differences could be attributed to the physicochemical characteristics of each mode, as diesel DEPs contained higher concentrations of polycyclic aromatic hydrocarbons (PAHs). This study addresses a research gap by quantifying the health effects of emissions from dual-fuel engines and highlights the potential of these systems to reduce DEP-induced toxicity.