Lung cancer, cardiopulmonary mortality, and long-term exposure to fine particulate air pollution

In vitro assessment of aryl hydrocarbon, estrogen, and androgen receptor-mediated activities of secondary organic aerosols formed from the oxidation of polycyclic aromatic hydrocarbons and furans

Biomass burning constitutes a significant source of fine particulate matter (PM2.5) in the atmosphere, particularly during winter due to residential wood heating. This source also emits substantial quantities of volatile and semi-volatile organic compounds, leading through (photo-)chemical and physical processes, to the formation of secondary organic aerosols (SOAs), accounting for a significant fraction of PM2.5. The current understanding of the biological effects of SOA resulting from the oxidation of major gaseous precursors emitted by biomass burning (e.g., polycyclic aromatic hydrocarbons (PAHs), phenols, furans) is still limited. Mechanism-based in vitro cellular bioassays targeting toxicologically relevant modes of action have proven valuable in assessing and quantifying the overall biological activity of complex mixtures like SOA, thereby revealing the presence of toxicologically relevant compounds. The main objective of this study was to investigate, using a battery of in vitro mechanism-based cellular bioassays, the aryl hydrocarbon (AhR), estrogen (ER), and androgen receptor (AR)-mediated activities of laboratory-generated SOA resulting from the oxidation of four PAHs and three furans. SOA was produced using an oxidation flow reactor (OFR) under either daytime (OH radicals) or nighttime (NO3 radicals) conditions. Furan-derived SOA did not exhibit any biological activity with the targeted endpoints. PAH-derived SOA, formed from AhR weakly or inactive PAHs, showed significant AhR-mediated activities. Notably, SOA resulting from naphthalene and acenaphthylene + acenaphthene demonstrated the highest AhR activation potency, with greater activities observed for SOA formed through NO3 radical oxidation. No endocrine-disrupting activity was observed for the PAH-derived SOA, similar to the individual parent PAHs (with the exception of fluorene and phenanthrene PAHs which were weekly anti-androgenic). These findings underscore the substantial contribution of PAH-derived SOA to the AhR-mediated activities of PM.

Significant Cross-Contamination Caused by Cooking Fume Transport between Dwelling Units in Multilayer Buildings

Cross-contamination in multiunit residential buildings is an inevitable but poorly studied issue. We conducted a 2-month monitoring campaign in a multilayer residential building, identifying 53 interunit kitchen exhaust transmission events (∼2 per day), causing enhanced exposure of particulate matters (PM), black carbon (BC), NOx, and CO and volatile organic compounds (VOCs) in both the kitchen and living room. These events resulted in a 40-80% increase in PM deposition in the respiratory systems for occupants in the living room, especially fine particles depositing in the alveolar region. Evidence indicates that these pollutant events originated from cooking fume transport. The geometric mean diameter of kitchen particles decreased from 76 nm during background periods to 62 nm during transport events, consistent with smaller PM from cooking activities. Furthermore, 30 cooking-related VOCs were identified as transport indicators, including hazardous species such as aldehydes. We confirmed that leakage of cooking fume through the shared kitchen exhaust duct led to cross-contamination, which can be effectively mitigated by using exhaust hoods, air cleaners, or opening windows during mealtimes. This research provides the first quantitative assessment of cooking emission transport between dwellings in multilayer housing, highlighting the significant impact of cross-contamination in high-density residential environments.

Anthropogenic climate change contributes to wildfire particulate matter and related mortality in the United States

Climate change has increased forest fire extent in temperate and boreal North America. Here, we quantified the contribution of anthropogenic climate change to human mortality and economic burden from exposure to wildfire particulate matter at the county and state level across the contiguous US (2006 to 2020) by integrating climate projections, climate-wildfire models, wildfire smoke models, and emission and health impact modeling. Climate change contributed to approximately 15,000 wildfire particulate matter deaths over 15 years with interannual variability ranging from 130 (95% confidence interval: 64, 190) to 5100 (95% confidence interval: 2500, 7500) deaths and a cumulative economic burden of $160 billion. Approximately 34% of the additional deaths attributable to climate change occurred in 2020, costing $58 billion. The economic burden was highest in California, Oregon, and Washington. We suggest that absent abrupt changes in climate trajectories, land management, and population, the indirect impacts of climate change on human-health through wildfire smoke will escalate.

Assessment of long-term exposure to traffic-related air pollution: An exposure framework

BACKGROUND

Exposure to ambient air pollution is associated with morbidity and mortality, making it an important public health concern. Emissions from motorized traffic are a common source of air pollution but evaluating the contribution of traffic-related air pollution (TRAP) emissions to health risks is challenging because it is difficult to disentangle the contribution of individual air pollution sources to exposure contrasts in an epidemiological study.

OBJECTIVE

This paper describes a new framework to identify whether air pollution differences reflect contrasts in TRAP exposures. Because no commonly measured pollutant is entirely specific to on-road motor vehicles, this exposure framework combined information on pollutants, spatial scale (i.e., geographic extent), and exposure assessment methods and their spatial scale to determine whether the estimated effect of air pollution in a given study was related to differences in TRAP.

METHODS

The exposure framework extended beyond the near-road environment to include differences in exposure to TRAP at neighborhood resolution ( ≤ 5 km) across urban, regional, and national scales. It also embedded a stricter set of criteria to identify studies that provided the strongest evidence that exposure contrasts were related to differences in traffic emissions.

RESULTS

Application of the framework to the transparent selection of epidemiological studies for a systematic review produced insights on assessing and improving comparability of TRAP exposure measures, particularly for indirect measures such as distances from roads. It also highlighted study design challenges related to the duration of measurements and the structure of epidemiological models.

IMPACT STATEMENT

This manuscript describes a new exposure framework to identify studies of traffic-related air pollution, a case study of its application in an HEI systematic review, and its implications for exposure science and air pollution epidemiology experts. It identifies challenges and provides recommendations for the field going forward. It is important to bring this information to the attention of researchers in air pollution exposure science and epidemiology because applying the broader lessons learned will improve the conduct and reporting of studies going forward.

An income-tailored energy efficiency rebate policy: Multi-dimensional benefit evaluation approach for upgrading heating furnaces in Ontario, Canada

A framework for evaluating the economic, environmental, and health benefits of upgrading residential heating furnaces in Ontario, Canada, is presented focusing on income-based disparities across seven groups. Energy efficiency programs often overlook income-based differences, limiting access to rebates. Key objectives include assessing benefits for consumers and society, and designing an income-tailored rebate policy. Benefits assessed include reductions in natural gas consumption, greenhouse gas emissions (CO2, methane, nitrous oxide), primary and secondary particulate matter (PM2.5) contaminants, and the prevention of premature mortality. The methods involve estimating energy consumption reductions and accounting for efficiency declines over time, emission factors, global warming potentials, intake fraction, concentration-response function, and a baseline health endpoint for environmental and health impact assessments. Natural gas price modeling, carbon taxes, and the value of statistical life are used for monetary benefit calculations. Findings reveal significant differences in per-household energy-saving benefits among income groups. Gas consumption reductions range from 7015 (lowest-income) to 19,416 m3 (highest-income), greenhouse gas reductions vary from 13.32 to 36.86 tons of CO2e, and PM2.5 reductions range from 0.85 to 2.36 kg (primary) and 8.27 to 22.90 kg (secondary). Savings (consumer and societal) range from $2669 to $7388 CAD. Collectively, 10 to 55 premature deaths are avoided. These disparities suggest that uniform rebate policies may not equitably support all income groups. An income-based tax rebate structure is recommended allocating 71.26% of the furnace price to the lowest-income group and 20.62% to the highest-income group, utilizing income tax data for eligibility to enhance upgrade uptake and optimize rebate distribution.

Assessing the burden of diseases attributed to exposure to ambient particulate matter by air quality modeling

This study aimed to assess PM2.5 exposure levels in Ahvaz, Iran, and quantify the associated burden of disease attributable to particulate pollution. To quantify uncertainty mortality and morbidity, the exposure response function model for probabilistic risk assessment was used. The analysis of aerosol variations by the Aerosol Optical Thickness indicated a decline in PM2.5 concentrations during pandemic. During the study period, the annual mean of PM2.5 concentrations exceeded the annual limit value established by the World Health Organization. Cause-specific mortality, including trachea bronchus lung cancer, stroke, and acute lower respiratory infections, also decreased by 14-28% in 2020. Restricted activity days and work days lost decreased by 11.8% and 13.8%, respectively, correlating with lower PM2.5 concentrations. Years lived with disability dropped from 242.7 to 170.4 years per 105 capita in 2020 during the pandemic. Mitigation strategies, including green infrastructure, industrial regulation, and improved urban planning, are needed to reduce health risks in this highly polluted region.

A study on the spatial distribution of life expectancy and its air pollution factors in China based on geographically weighted regression

Background

Life expectancy in China has demonstrated a consistent upward trend, yet significant disparities persist across provinces. Addressing these regional imbalances necessitates a comprehensive investigation into the determinants of life expectancy. Previous research has largely overlooked the critical role of spatial heterogeneity, which is essential for understanding the underlying mechanisms driving these disparities. By incorporating spatial analysis, this study aims to identify and address the factors contributing to the uneven distribution of life expectancy across China, thereby providing a more nuanced understanding of regional health inequalities.

Methods

Therefore, this study investigated the spatial distribution characteristics and patterns of life expectancy across 31 provinces in China in 2020 by conducting descriptive and spatial autocorrelation analyses, utilizing life expectancy data alongside key air pollution indicators (PM2.5, SO2, NO2, and PM10). To address spatial heterogeneity, the geographically weighted regression (GWR) model was applied to assess the regional variations in the impact of air pollutants on life expectancy. This approach allows for the incorporation of geographic coordinates into the regression coefficients, capturing localized effects and providing a more nuanced understanding of the relationship between air pollution and life expectancy across different regions.

Results

The findings revealed that in 2020, life expectancy in China exhibited a distinct east-to-west decreasing trend, demonstrating significant spatial autocorrelation that was predominantly characterized by two aggregation patterns: high-high and low-low clusters. The analysis demonstrated that air pollutants, including SO2, NO2, and PM10, exerted significant influences on life expectancy, albeit with regional variations. Specifically, SO2 exhibited a more pronounced negative impact on life expectancy in southern cities, while NO2 demonstrated a stronger effect in northwestern regions. Notably, PM10 showed a significant influence limited to Yunnan Province, highlighting the spatial heterogeneity in the relationship between air pollution and life expectancy across China.

Conclusion

These findings highlight the imperative for local governments to develop and implement region-specific air pollution control measures, taking into account the unique environmental and socio-economic conditions of their respective areas.

Smoke Exposure and Respirator Use Among Wildland Firefighters: A Narrative Review

Climate change contributes to warm, dry conditions, which leads to longer and more active fire seasons. Wildland firefighters work long hours in smoky conditions without regulations requiring respiratory protection. Wildfire smoke has many toxic components, including high levels of fine particulate matter (PM2.5). Regular monitoring for short- and long-term health outcomes in wildland firefighter populations is uncommon. However, extrapolating from knowledge about the individual components of smoke, it is likely that the firefighters' health is negatively affected. Firefighters are routinely exposed to dangerous levels of smoke, which may lead to both acute and chronic health consequences. Current guidelines from Occupational Safety and Health Administration (OSHA), the U.S. Forest Service (USFS), and the Interagency Standards for Fire and Fire Aviation Operations do not recommend respirator use for wildland firefighters. The methodologies used to quantify exposure and harm likely underestimate actual risks. Although there are no respirators that can filter all known harmful components of wildfire smoke, this review examines the potential benefit of respirator use by reducing some of the most harmful components of the smoke. Smoke exposure among wildland firefighters needs to be further characterized and quantified. Regulations should be reassessed to accurately reflect the exposure and potential harm that firefighters face. This narrative review gathers information from peer-reviewed scientific literature, government publications, news articles, and personal conversations with both public- and private-sector professionals. The objectives are to describe the likely health effects of wildland firefighting, evaluate the evidence behind current respiratory protection guidelines, and propose potential solutions.

Long-term ambient ozone exposure and lung cancer mortality: A nested case-control study in Korea

The link between long-term exposure to tropospheric ozone (O3) and risk of lung cancer mortality remains uncertain. We aimed to provide new insights into the association between long-term O3 exposure and lung cancer mortality in Korea. A nested case-control study was conducted within a cancer-free cohort of 1,731,513 individuals who underwent health screenings provided by the National Health Insurance Service in 2006-2007. A total of 7133 lung cancer deaths that occurred from January 1, 2012, to December 31, 2021, were matched to 28,532 controls at a 1:4 ratio based on propensity scores. Daily 24-h and 8-h maximum O3 concentrations, averaged year-round and during the warm season from 2006 to 2010, were estimated for participants based on their residential addresses using the Community Multiscale Air Quality model. O3 concentrations rise during the daytime, also exhibiting seasonal variations, with the highest levels occurring in the warm season. Elevated risk of lung cancer mortality was observed among participants in the highest quartile of O3 exposure compared with those in the lowest quartile, yielding odds ratios ranging from 1.15 to 1.27. However, when exposure to particulate matter with an aerodynamic diameter of 2.5 μm or less (PM2.5) was further adjusted for, the adverse risk of long-term O3 exposure was attenuated, even tending to be protective. Notably, participants with both high O3 and high PM2.5 exposures had an increased risk of lung cancer mortality. Furthermore, regional differences were observed, with a significantly higher risk in rural areas. Findings of this study suggest that long-term exposure to O3, especially in combination with PM2.5 exposure, is associated with an excess risk of lung cancer mortality, underscoring the importance of addressing the O3 and PM2.5 interaction in lung cancer prevention.

Effects of urban particulate matter on the secondary structure of albumin

Particulate air pollution is an environmental problem recognized as a global public health issue. Although the toxicological effects of environmental particle matter (PM) have been reported, the mechanism underlying the effect of PM on protein conformational changes, which are associated with the development of various diseases, has yet to be elucidated. In this study, we investigated the effect of urban PM on the secondary structure of proteins using bovine serum albumin (BSA). An urban aerosol (CRM28) was used as the original PM (PMO) and washed with acetone to investigate the effect of PM with two different chemical compositions. After washing with acetone, the remaining PM fraction contained decreased amounts of ions and carbon, while the metallic concentration was increased; thus, this PM fraction was labeled as PMM. After incubation of BSA with PM, the samples were subjected to Fourier-transform infrared (FT-IR) spectroscopy to investigate the changes in the absorption peak of the amide I band. BSA incubated with PMO and PMM showed an increase in the β-sheet ratio to the total secondary structure. Furthermore, the β-sheet content was more significantly increased when mixed with PMM (by 22.6%), indicating a more significant effect of the metallic fraction on the formation of β-sheets. In comparison, the lowest total amount of α-helix and β-sheets (with a decrease of 8.5%) was observed after incubation with PMO, associated with the protein partial unfolding in the presence of ions and carbonaceous PM constituents. The potential of a long-term effect of PM composition on protein structure would be of future interest in in vivo time-course studies.

Mechanism of microplastic and nanoplastic emission from tire wear

Tire and brake-wear emissions, in particular nanoparticulate aerosols, can potentially impact human health and the environment adversely. While there is considerable phenomenological data on tire wear, the creation and environmental persistence of particulate pollutants is not well understood. Here, we unequivocally show that normal mechanical tire wear results in two distinct micro and nanoplastic (MNP) populations: a smaller, aerosolized fraction (<10 μm), and larger microplastics. Nanoplastic emissions follow a power law distribution that we show is consistent with the classical arguments of Archard, and Griffiths. Nanoplastic pollution increases dramatically with vehicle speed and weight, as the power law distribution characterizing these gets steeper. Charge stabilization of the tire wear nanoparticles keeps them suspended, while microplastics settle due to gravity. Larger microplastics are formed by sequential wear processes and show a log-normal distribution, as anticipated by Kolmogorov. Thus, the particle size distribution provides mechanistic insights to tire fragmentation: the aerosolized fraction is determined by power input to the tire while the larger microplastics are determined by sequential wear processes due to tire-road surface interactions, independent of vehicle weight and speed.

Particulate matter air pollution as a cause of lung cancer: epidemiological and experimental evidence

Air pollution has a significant global impact on human health. Epidemiological evidence strongly suggests that airborne particulate matter (PM), the dust components of polluted air, is associated with increased incidence and mortality of lung cancer. PM2.5 (PM less than 2.5 µm) from various sources carries different toxic substances, such as sulfates, organic compounds, polycyclic aromatic hydrocarbons, and heavy metals, which are considered major carcinogens that increase lung cancer risk. The incidence and mortality of lung cancer caused by PM2.5 exposure may be due to significant geographical differences, and can be influenced by various factors, including local sources of air pollution, socioeconomic conditions, and public health measures. This review aims to provide comprehensive insights into the health implications of air pollution and to inform strategies for lung cancer prevention, by summarising the relationship between exposure to PM2.5 and lung cancer development. We explore the different sources of PM2.5 and relevant carcinogenic mechanisms in the context of epidemiological studies on the development of lung cancer from various geographical regions worldwide.

Clinical impact of air pollution on SPECT myocardial perfusion imaging

BACKGROUND

Air pollution contributes to cardiovascular morbimortality. Air pollution effects on cardiovascular function assessed from non-invasive and invasive imaging have been reported but never on myocardial perfusion. This study aimed to characterize relations of air pollution exposure to myocardial perfusion imaging (MPI).

METHODS

Patients referred to SPECT (single-photon emission computed tomography) MPI were prospectively enrolled between 2017 and 2020. Myocardial ischemia was assessed from the SPECT. Moderate-to-severe ischemia was defined as a > 10 % ischemic myocardium. Exposures to particulate matter (PM2.5 and PM10) and NO2 at the home address were characterized via a 10-meter resolution air pollutant-dispersion model and air quality monitoring system data. Associations of exposures with scintigraphy parameters were assessed through multivariable regressions, and potential modifying effects by sex and BMI were investigated.

RESULTS

A total of 1,585 participants were prospectively included (mean age 67.7 ± 11.6 years, 63.3 % male); 148 (9.3 %) patients presented a moderate-to-severe ischemia. In multivariate analysis, the odds of moderate-to-severe ischemia was increased, with adjusted odds-ratio (ORa) of 1.39 [95 % confidence interval (95 % CI): 1.07-1.80; p = 0.013], 1.33 (95 % CI: 1.01-1.75; p = 0.042), and 1.22 (95 % CI: 0.96-1.57; p = 0.10) for each increase of one Interquartile Range (IQR) in PM2.5, PM10 and NO2 exposure, respectively (IQR equal to 3.3, 4.3 and 10.0 µg/m3, respectively). With further adjustment for cardiometabolic diseases and symptoms, only the association with PM2.5 remained statistically significant: ORa 1.34 (95 % CI: 1.03-1.75, p = 0.031) for each one-IQR increase. Associations with PM10 and PM2.5 tended to be stronger in women (interaction p-value equal to 0.11 and 0.077, respectively).

CONCLUSION

We provide new insights into a mechanism by which particulate air pollution may influence cardiovascular risk. Exposure to PM was associated with moderate-to-severe ischemia, particularly in women.

Air pollution and its impact on cancer incidence, cancer care and cancer outcomes

Air pollution is an under-recognised global health threat linked to an increased risk of cancers and is due primarily to the burning of fossil fuels. This review provides a high-level overview of the associations between outdoor and indoor air pollution and cancer risk and outcomes. Outdoor air pollutants are largely due to the burning of fossil fuels from human activities, although there is growing data implicating outdoor pollution from wildfire smoke. Indoor air pollution is primarily caused by burning solid fuel sources such as wood, coal and charcoal for household cooking and heating. There is a growing number of pieces of evidence linking exposure to pollution and the risk of developing cancers. The strongest evidence is seen on the positive association of air pollution, particularly particulate matter 2.5 with lung cancer. Emerging data implicate exposure to pollutants in the development of breast, gastrointestinal and other cancers. The mechanisms underlying these associations include oxidative stress, inflammation and direct DNA damage facilitated by pollutant absorption and distribution in the body. References were identified through a PubMed search for articles published in 2000 to October 2024 using the terms 'air pollution' or 'pollutants' and 'carcinoma' or ''cancer'. Air pollution poses significant risks to health. Its health impacts, including cancer risks, are often underestimated. Hazardous pollutants have been studied in several epidemiological cohort studies. Despite the mounting evidence, air pollution is often overlooked in predictive cancer risk models and public health intervention.

Aerosol Capture for Coupling to Microfluidics: A Miniaturized Low-Cost Device for Size-Resolved Particle Collection

Inhaled aerosols impact human health by depositing harmful species in the lungs (e.g., metals and organic pollutants) and act as a key pathway for airborne disease transmission. Aerosol inhalation is highly size-dependent, with smaller particles (particulate matter <2.5 μm, PM2.5) depositing deeper in the lungs (e.g., alveoli) leading to strong correlations between PM2.5 and mortality, along with other respiratory and cardiovascular diseases. A longstanding challenge for detailed aerosol chemical analysis is that most PM2.5 health studies collect offline samples, which are subsequently analyzed offsite, requiring high-cost collectors and significant downstream effort and cost. Herein, we present a low-cost, miniature 3D-printed impactor coupled to a microfluidic channel to allow for downstream analysis of PM in liquid. After size-segregated collection of airborne particles within the device, water is flowed through a microfluidic channel that resuspends insoluble particles or dissolves soluble particles. Size-dependent collection efficiencies (50% cutoff diameters, d50's) for the supermicron (PM>1) impactor were 0.8 and 1.0 μm using monodisperse (polystyrene latex spheres) and polydisperse (red-fluorescent spheres) standards, respectively. Coarse (PM>2.5) impactor d50's were 2.4 and 2.6 μm, respectively. Optical photothermal infrared (O-PTIR) and Raman microspectroscopy confirmed collected particle composition. The sizes of re-entrained PSLs (1, 1.25, and 1.5 μm) were measured to have diameters of 1.0, 1.2, and 1.5 μm, respectively, with a Coulter Counter, indicating the successful downstream analysis of collected particles without modification during impaction and resuspension. Soluble particles (ammonium sulfate) were dissolved by the flowing water and measured with ion chromatography. This study shows that 3D-printed impactors are capable of collecting particles with a well-defined size cut, as well as nondestructively resuspending and chemically analyzing the particles. These 3D-printed devices are a miniaturized, low-cost (<$2) option that sets the stage for semicontinuous microfluidic analysis of size-selected aerosols to evaluate health impacts ranging from toxin exposure to disease transmission.

A high resolution multipollutant assessment of health damages due to the onroad sector in Boston, Massachusetts

Onroad vehicular emissions can adversely affect the health of people both near-road and regionally through exposure to O3, NO2, and PM2.5. While multiple studies have characterized the overall air quality and health benefits of emissions from the transportation sector, fewer studies have modeled the benefits of transportation policies at higher geographic resolution relevant to communities. We used the United States Environmental Protection Agency (U.S. EPA)'s Community Multiscale Air Quality (CMAQ) Version 5.2.1 coupled with the decoupled direct method (DDM) within a nested grid with maximum resolution of 1.33 km × 1.33 km. We predicted O3, NO2, and PM2.5 sensitivities to a large matrix of input parameters concerning five different vehicle classes, five precursors, and six subregions within the Boston metropolitan area (Massachusetts, U.S.). We used the Environmental Benefits Mapping and Analysis Program in R (BenMAPR) to estimate health impacts given concentration-response functions from epidemiological studies, focusing on premature mortalities as well as asthma exacerbations. Based upon the sensitivity matrix, for NO2 and PM2.5, NOx and directly emitted PM2.5 (PPM) have the maximum sensitivity, respectively. O3 is found to be more sensitive to VOC emissions than NOx emissions. We also found that NH3 and SO2 emissions are the next most significant contributors to PM2.5 concentrations after PPM. Our overall findings suggest that approximately 342 premature deaths (95 % CI: 200-465) occur annually in the region due to on-road emissions, with 87 % of these linked to elevated NO2 concentrations. For PM2.5 from PPM, the most densely populated subregion had damages per ton 1.2 to 1.8 times higher than for the other inner core regions and three times higher than suburban regions. Substantial variation in health damages per ton of emissions was observed across precursor pollutants, source regions, and vehicle classes, underscoring the need for targeted emission reduction strategies. This study highlights the importance of high-resolution air quality modeling to accurately capture intra-urban health impacts and inform effective policymaking.

Disentangling the effects of various risk factors and trends in lung cancer mortality

Lung cancer is a leading cause of mortality in oncological classifications, yet the impact of various risk factors on lung cancer mortality (LCM) in non-smokers remains unclear. This study aims to weigh out the diverse impact of multiple risk factors on LCM rates and identify trends in LCM rates worldwide. We initially employed Random Forest Tree (RFT) and Gradient Boosting Regression (GBR) to identify common primary factors influencing LCM. After eliminating four common primary factors, a comparative analysis between partial and Pearson correlations was conducted to filter out significant factors in the correlations between risk factors and LCM rates across 204 countries from 2005 to 2019. The findings show that excluding the impacts of occupational exposure to arsenic, smoking, residential radon, occupational exposure to silica, occupational exposure to asbestos, high systolic blood pressure, secondhand smoke, child wasting, and alcohol use had a considerably greater impact on LCM than particular matter pollution (PM2.5). Furthermore, a Multiple Joinpoint Regression analysis identified increasing trends of LCM rates in the 142 countries (e.g., China and India); decreasing trends in 38 countries (e.g., Denmark and Norway), and stable trends in 24 countries (e.g., Sudan, Mali, and Australia). This research suggests that in addition to considering the effects of occupational exposure to arsenic, smoking, residential radon, and occupational exposure to silica on LCM rates, occupational exposure to asbestos, high systolic blood pressure, secondhand smoke, child wasting, and alcohol use should be considered in lung cancer prevention strategies, especially in countries with increasing trends of LCM rates.

Particles emitted from smouldering peat: size-resolved composition and emission factors

Peat fires emit large quantities of particles and gases, which cause extensive haze events. Epidemiological studies have correlated wildfire smoke inhalation with increased morbidity and mortality. Despite this, uncertainties surrounding particle properties and their impact on human health and the climate remain. To expand on the limited understanding this laboratory study investigated the physicochemical characteristics of particles emitted from smouldering Irish peat. Properties investigated included number and mass emission factors (EFs), size distribution, morphology, and chemical composition. Fine particles with a diameter less than 2.5 μm (PM2.5), accounted for 91 ± 2% of the total particle mass and the associated mass EF was 12.52 ± 1.40 g kg-1. Transmission electron microscopy imaging revealed irregular shaped metal particles, spherical sulfate particles, and carbonaceous particles with clusters of internal particles. Extracted particle-bound metals accounted for 3.1 ± 0.5% of the total particle mass, with 86% of the quantified metals residing in the fraction with a diameter less than 1 μm. Redox active and carcinogenic metals were detected in the particles, which have been correlated with adverse health effects if inhaled. This study improves the understanding of size-resolved particle characteristics relevant to near-source human exposure and will provide a basis for comparison to other controlled and natural peatland fires.

Environmental justice beyond race: Skin tone and exposure to air pollution

Recent research, focused mostly on the United States and Western Europe, shows that marginalized communities often face greater environmental degradation. However, the ethnoracial categories used in these studies may not fully capture environmental inequality in the Global South. Moving beyond conventional ethnoracial variables, this study presents findings exploring the link between skin tone and fine particulate matter (PM2.5) exposure in Colombia. By matching household geolocations from a large-scale longitudinal survey with satellite-based PM2.5 estimates, we find that skin tone predicts both initial pollution exposure levels and their changes over time. Although average exposure levels remained stable during our study period, the environmental justice (EJ) landscape in Colombia contemporaneously underwent a complete transformation. In 2010, lighter-skinned individuals faced higher PM2.5 exposure, but darker-skinned individuals experienced steeper increases in the following years. By 2016, the EJ gap had reversed, with people with the darkest skin tones exposed to PM2.5 levels nearly one SD higher than those faced by people with the lightest skin tones. These patterns remain robust when controlling for a comprehensive set of theoretically relevant covariates, including ethnoracial self-identification and income. Disproportionate exposure to pollution from fires partially explains the observed disparities. Decomposition analysis shows that this variable, local collective action, and economic marginalization account for a sizeable share of the EJ gap. However, one-third of the gap remains unexplained by observable characteristics. With climate change intensifying fire incidence, the disproportionate disease burdens that vulnerable groups face might deepen unless policy measures are taken to reverse this trend.

Short-Term Effects of Extreme Heat, Cold, and Air Pollution Episodes on Excess Mortality in Luxembourg

This study aims to assess the short-term effects of extreme heat, cold, and air pollution episodes on excess mortality from natural causes in Luxembourg over 1998-2023. Using a high-resolution dataset from downscaled and bias-corrected temperature (ERA5) and air pollutant concentrations (EMEP MSC-W), weekly mortality p-scores were linked to environmental episodes. A distributional regression approach using a logistic distribution was applied to model the influence of environmental risks, capturing both central trends and extreme values of excess mortality. Results indicate that extreme heat, cold, and fine particulate matter (PM2.5) episodes significantly drive excess mortality. The estimated attributable age-standardized mortality rates are 2.8 deaths per 100,000/year for extreme heat (95% CI: [1.8, 3.8]), 1.1 for extreme cold (95% CI: [0.4, 1.8]), and 6.3 for PM2.5 episodes (95% CI: [2.3, 10.3]). PM2.5-related deaths have declined over time due to the reduced frequency of pollution episodes. The odds of extreme excess mortality increase by 1.93 times (95% CI: [1.52, 2.66]) per extreme heat day, 3.49 times (95% CI: [1.77, 7.56]) per extreme cold day, and 1.11 times (95% CI: [1.04, 1.19]) per PM2.5 episode day. Indicators such as return levels and periods contextualize extreme mortality events, such as the p-scores observed during the 2003 heatwave and COVID-19 pandemic. These findings can guide public health emergency preparedness and underscore the potential of distributional modeling in assessing mortality risks associated with environmental exposures.

Environmental exposure and cancer occurrence in dogs: a critical appraisal of evidence

Cancer is a significant contributor to morbidity and mortality in humans and is also the leading cause of death in dogs. It is estimated that up to 20 % of human cancers can be explained by environmental exposures to carcinogens. It has been hypothesized that companion animals such as dogs could not only be a model for the complex pathogenic processes of human cancers, but also act as sentinels for environmental carcinogens due to their relative shorter longevity, spontaneous occurrence of tumours, and intimate relationship with our everyday environments. This review aimed to provide the epidemiological evidence on the role of the environment in the development and progression of tumours in the canine species.

Is it worth implementing the Blue Sky Defense Battle initiative? A cost-benefit analysis of the Chengdu case

To mitigate air pollution, China began implementing its Three-Year Action Plan for Winning the Blue Sky Defense Battle in 2018. The rapid decline in the annual average concentration of particulate matter PM2.5 raised the authors' interest in the cost efficiency of the implementation of the action plan. Taking Chengdu as an example, this study assesses the costs and benefits of the implementation of the Action Plan by investigating the direct abatement costs, the change of PM2.5-related disease burdens, and the resulting health benefits. The results show that the abatement costs of air pollution in Chengdu amounted to 8.77 billion yuan from 2018 to 2020, the number of beneficiaries over three years could reach 353,546, and the health benefits amounted to 9.79 billion yuan. The health benefit outweighs the abatement cost. Furthermore, among the abatement measures, the cost of transportation infrastructure development accounted for 92.83% in the total. Considering its co-benefit of industry development and CO2 abatement, the true benefits should far outweigh the costs. The Monte Carlo simulation further confirms the economic efficiency of the Three-Year Action Plan. Although the direct costs of the Action Plan are significant, the marginal health benefits of further alleviating PM2.5 may still be greater than the marginal costs, because the population is large and densely distributed in Chengdu. Actions on improving air quality still have the potential to further unlock health benefits for large cities like Chengdu.

Insight into the abundance and optical characteristics of water-soluble organic compounds (WSOC) in PM2.5 in urban areas

Airborne particulate matter (PM) poses significant environmental and health challenges, particularly in urban areas. This study investigated the characteristics of water-soluble organic compounds (WSOC) in PM2.5 (PM with an aerodynamic diameter of 2.5 μm or less) in Singapore, a tropical Asian city-state, over a six-month period. Specifically, we examined the abundance, optical properties, and fluorescence characteristics of WSOC in PM2.5 collected from various urban locations, employing complementary instrumental techniques, parallel factor (PARAFAC) modeling, and Kohonen's self-organizing map (SOM). Our findings highlight that the differences in WSOC characteristics between sites reflect the influence of primary emissions of PM and secondary PM formation processes. Concentrations of PM2.5 and WSOC on roadsides are influenced by vehicular traffic composition and volume. Under conducive atmospheric conditions, volatile organic compounds (VOCs) from vehicle emissions are oxidized to form WSOC, with its chemical composition dependent on whether oxidation occurs in the gas or aqueous phase. The findings also indicate that while vegetation barriers (VBs) planted along the roads in this study do not significantly reduce PM2.5 concentrations, they alter the chemical composition and light absorption properties of WSOC. The capacity of VBs to retain PM less than 1 μm in size shows their potential in reducing exposure to harmful traffic emissions. Moreover, fluorescence analysis revealed the presence of humic-like and protein-like compounds, underscoring the complex chemical nature of WSOC. This study provides a comprehensive insight into the molecular composition and properties of WSOC in PM2.5.

Population exposure evaluation and value loss analysis of PM2.5 and ozone in China

In recent years, increasing concern has been observed in China regarding PM2.5 and ozone as major atmospheric pollutants, which pose significant risks to air quality and public health. This study analyzed the spatial and temporal distribution patterns of PM2.5 and O3 in 31 provinces of China in 2022 using mathematical statistics and kriging interpolation, assessed the exposure risk of the public applying a population exposure risk model, evaluated the number of premature deaths with the help of an exposure-response function, and estimated the loss of health value according to a modified human capital approach. The findings indicated that: First, the PM2.5 concentration followed a monthly "U" trend, while the O3 concentration exhibited an inverted "U" trend. Simultaneous high levels of PM2.5 and O3 were primarily noted in spring. In contrast, PM2.5-dominated and ozone-dominated pollution were more prevalent in winter and summer, respectively. Second, the risk of public exposure to them displayed a spatially parallel distribution for PM2.5 and O3, with higher risks generally found east of the Heihe-Tengchong Line compared to the west. Third, an estimated 31.99 × 104 individuals were projected to suffer premature mortality, with 22.58 × 104 and 9.41 × 104 linked to PM2.5 and ozone, respectively. The economic costs associated with premature deaths due to them were 214.31 billion and 94.53 billion yuan, respectively, representing 7.53% of GDP. These results were based on well-continued large spatial scale PM2.5 and O3 concentration data, and population data, and highlighted the significant impacts of both on public health in China. The combination of socio-economic data to quantify the loss of health value enriched the study and provided a targeted program for developing pollution control measures in different regions of China.

Tracheal, bronchus, and lung cancer mortality and air pollution exposure in Tuscany, Italy: Bayesian Health Impact Assessment and Global Sensitivity Analysis on a sub-regional scale

Outdoor air pollution is a significant risk factor for tracheal, bronchus, and lung (TBL) cancer. This study employs a Bayesian approach to evaluate TBL cancer mortality due to air pollution in Tuscany, Central Italy, in 2023. Using locally validated data, we assessed the impact of fine particulate matter (PM10 and PM2.5) and nitrogen dioxide (NO2) in terms of attributable deaths and years of life lost (YLL). Our three-step methodology included: (1) Bayesian modeling to derive posterior distributions for life expectancy, pollution levels, mortality rates, and exposure-response functions (inputs); (2) Monte Carlo simulations to propagate uncertainty from the inputs to the impact metrics (outputs); and (3) Global Sensitivity Analysis (GSA) to quantify the influence of each input on the outputs. The largest impact was estimated for PM2.5, with 432 deaths (50% CrI: 174;705) and 6,500 YLL (50% CrI: 2,624;10,613) in the region due to annual average concentrations exceeding the WHO threshold of 5μg/m3. Central districts, with higher exposure levels, were particularly affected, reporting 14 attributable deaths and 207 attributable YLL per 100,000 inhabitants. The GSA indicated that uncertainty in exposure-response functions and annual average concentrations of air pollutants significantly affected outcomes, highlighting the need to strengthen the regional air quality network and conduct local studies to address effects heterogeneity. Our findings highlight the value of high-quality local health assessments for identifying critical areas, setting intervention priorities, and informing context-specific action plans.

Health benefits of a reduction in ambient fine particulate matter levels for post-neonatal infant survival in Taiwan

Infants' and children's health is particularly susceptible to exposure to various environmental contaminant insults as their immune systems are immature and daily activities may present differing patterns of exposure. Although some studies noted an association between long-term exposure to ambient fine particulate matter (PM2.5) and increased infant mortality frequency, few investigations examined the relationship between reduced exposure to PM2.5 and changes in infant mortality rates. Therefore, this study was conducted to determine whether diminished levels of PM2.5 in Taiwan improved post-neonatal infant health. Avoidable premature post-neonatal infant mortality was employed as an indicator of health impact. A mean value was calculated for annual PM2.5 levels across Taiwan for the years 2006, 2015, and 2023. Using these averages and following WHO methodology, differences in the number of post-neonatal infant deaths attributed to ambient PM2.5 exposure were determined. PM2.5 concentrations fell markedly throughout Taiwan over the 20-year study period. In conjunction with this decline, a lowered health burden was noted, which was represented as a fall in post-neonatal infant deaths (14.8% in 2006 to 10.3% in 2023). Reduction in annual levels of PM2.5 to 10 µg/m3 was associated with a decrease in the total burden of post-neonatal infant mortality occurrence, with a 5.58-9.31% decline in PM2.5-related deaths during that period. Evidence indicates that exposure to PM2.5 air pollution poses a significant burden to Taiwan children's health. Our findings indicate that the potential benefits to children's health need to be given importance when considering improving air quality policies.

Impact of Emission Standards on Fine Particulate Matter Toxicity: A Long-Term Analysis in Los Angeles

This study examines long-term trends in fine particulate matter (PM2.5) composition and oxidative potential in Los Angeles based on data from the University of Southern California's Particle Instrumentation Unit, with chemical composition retrieved from the EPA's Air Quality System (AQS). While regulatory interventions have reduced PM2.5 mass concentration and primary combustion-related components, our findings reveal a more complex toxicity pattern. From 2001 to 2008, the PM2.5 oxidative potential, measured via the dithiothreitol (DTT) assay, declined from ~0.84 to ~0.16 nmol/min/m3 under stringent tailpipe controls. However, after this initial decline, PM2.5 DTT stabilized and gradually increased from ~0.35 in 2012 to ~0.97 nmol/min/m3 by 2024, reflecting the growing influence of non-tailpipe emissions such as brake/tire wear. Metals, such as iron (Fe, ~150 ng/m3) and zinc (Zn, ~10 ng/m3), remained relatively stable as organic and elemental carbon (OC and EC) declined, resulting in non-tailpipe contributions dominating PM2.5 toxicity. Although PM2.5 mass concentrations were effectively reduced, the growing contribution of non-tailpipe emissions (e.g., brake/tire wear and secondary organic aerosols) underscores the limitations of mass-based standards and tailpipe-focused strategies. Our findings emphasize the need to broaden regulatory strategies, targeting emerging sources that shape PM2.5 composition and toxicity and ensuring more improvements in public health outcomes.

Intra-Continental Transport of Western Wildfire Smoke Heightens Health Risks Across North America

Wildfires in North America, particularly in western states, have caused widespread environmental, economic, social, and health impacts. Smoke from these fires travels long distances, spreading pollutants and worsening the air quality across continents. Vulnerable groups, such as children, the elderly, and those with preexisting conditions, face heightened health risks, as do firefighters working in extreme conditions. Wildfire firefighters are of particular concern as they are fighting fires in extreme conditions with minimal protective equipment. This study examined wildfire smoke during July-August 2021, when intense fires in Canada and the western U.S. led to cross-continental smoke transport and caused significant impacts on the air quality across North America. Using the GEOS-Chem model, we simulated the transport and distribution of PM2.5 (particulate matter with a diameter of 2.5 μm or smaller), identifying significant carcinogenic risks for adults, children, and firefighters using dosimetry risk methodologies established by the U.S. EPA. Significant carcinogenic risks for adult, child, and firefighter populations due to exposure to PM2.5 were identified over the two-month period of evaluation. The findings emphasize the need for future studies to assess the toxic chemical mixtures in wildfire smoke and consider the risks to underrepresented communities.

New mechanisms of PM2.5 induced atherosclerosis: Source dependent toxicity and pathogenesis

Exposure to fine particulate matter (PM2.5) is recognized to induce atherosclerosis, but the underlying mechanisms are not fully understood. This study used ambient PM2.5 samples collected in one of the highly polluted regions of Guanzhong Plain in China (2017-2020) and an ApoE-/- mouse model to investigate the association between exposure to PM2.5 and atherosclerosis. Despite a substantial decrease in the ambient concentration of PM2.5 from 266.7 ± 63.9 to 124.4 ± 37.7 μg m-3 due to the execution of a series of emission controls, cardiovascular toxicity due to exposure to PM2.5 remained at a significantly high level compared with the Control group. Moreover, the result highlighted that biomass burning (BB) showed an increased contribution to PM2.5 while most anthropogenic sources decreased. This study found that PM2.5 exposure led to vascular oxidative stress and inflammation, accelerated atherosclerotic plaque growth, and altered vascular proliferation pathways. The latter two mechanisms provide new insights into how PM2.5 enhanced the processes of atherosclerosis, promoted lipoprotein cholesterol (LDL-C) absorption in vascular cells, and directed stimulation of cell function factors (VEGF and MCP-1), which are highly associated by PI3K/AKT signaling pathway. Polycyclic aromatic hydrocarbons (PAHs) and their derivatives, and certain biomarkers showed strong correlations with bio-reactivity, while BB was identified as a major contributor to toxicity of PM2.5. The findings offer new insights into the role of PM2.5 promoting atherosclerosis and provide recommendations for controlling PM2.5 pollution to prevent and treat the disease particularly for susceptible populations.

Global impact of PM2.5 on cardiovascular disease: Causal evidence and health inequities across region from 1990 to 2021

PM2.5 is an important environmental risk factor for cardiovascular disease (CVD) and poses a threat to global health. This study combines bibliometric analysis, Mendelian randomization (MR), and Global Burden of Disease (GBD) data to comprehensively explore the relationship between PM2.5 exposure and CVD. MR analyses provided strong evidence for causality, reinforcing findings from traditional observational studies. The estimated global burden of PM2.5-related CVD indicated, that there exist significant impacts on the elderly, men, and populations in low and medium socio-demographic index (SDI) areas. This study further found that population growth and aging are the main drivers of this burden with large inequities, although medical advances have mitigated some of the effects. Overall, the opportunity to reduce the burden of CVD remains significant, particularly in medium SDI countries. Projections to 2045 suggested that the absolute burden will increase, while age-standardized rates will decline due to improvements in air quality and health care. These findings emphasized the urgent need for targeted interventions to mitigate the deleterious effects of PM2.5 on global cardiovascular health and to address health inequalities between regions.

Benzo[a]pyrene and phenanthrene hemoglobin adducts as biomarkers of longer-term air pollution exposure

Urinary hydroxylated-polycyclic aromatic hydrocarbons (PAHs), with half-life less than 2 days, are established biomarkers of short-term exposure to PAHs, a ubiquitous constituent of air pollution mixture. In this study, we explore the use of PAHs-hemoglobin adducts as biomarkers of longer-term exposure to air pollution by leveraging an extant resource of blood samples collected from 235 pregnant women residing in Rochester, NY. We measured red blood cells for benzo[a]pyrene-tetrols (BaPT) and phenanthrene-tetrols (PHET), both of which are hydrolysis products of PAH-hemoglobin adduct. We utilized previously estimated PM2.5 and NO2 concentrations within the 1 km2 grid surrounding each participant's residence, calculated for up to 20 weeks before the blood collection date. Associations between PAHs tetrols and cumulative exposures to ambient PM2.5 or NO2 over different time periods were examined using a linear mixed-effects model with participant-specific random intercepts adjusting for season, gestation age, maternal age, maternal income level, and pre-pregnancy BMI. We observed positive associations between PHET concentration and cumulative PM2.5 exposure over gestational weeks 12-17, and between BaPT concentration and cumulative PM2.5 exposure over gestational weeks 3-16 prior to sample collection. Each interquartile range (IQR) increase in 14 week PM2.5 exposure (1.26 μg m-3) was associated with a 9.02% (95% CI: 0.30%, 17.7%) increase in PHET and a 12.8% (95% CI: 1.09%, 23.5%) increase in BaPT levels. In contrast, no associations were observed between either biomarker and cumulative NO2 exposures. These findings underscore the potential of PAH-hemoglobin adducts as longer-term (weeks to 4 months) exposure biomarkers of ambient PM2.5.

Differential Cytotoxicity and Inflammatory Responses to Particulate Matter Components in Airway Structural Cells

Particulate matter (PM) is a major component of ambient air pollution. PM exposure is linked to numerous adverse health effects, including chronic lung diseases. Air quality guidelines designed to regulate levels of ambient PM are currently based on the mass concentration of different particle sizes, independent of their origin and chemical composition. The objective of this study was to assess the relative hazardous effects of carbonaceous particles (soot), ammonium nitrate, ammonium sulfate, and copper oxide (CuO), which are standard components of ambient air, reflecting contributions from primary combustion, secondary inorganic constituents, and non-exhaust emissions (NEE) from vehicular traffic. Human epithelial cells representing bronchial (BEAS-2B) and alveolar locations (H441 and A549) in the airways, human lung fibroblasts (HFL-1), and rat precision-cut lung slices (PCLS) were exposed in submerged cultures to different concentrations of particles for 5-72 h. Following exposure, cell viability, metabolic activity, reactive oxygen species (ROS) formation, and inflammatory responses were analyzed. CuO and, to a lesser extent, soot reduced cell viability in a dose-dependent manner, increased ROS formation, and induced inflammatory responses. Ammonium nitrate and ammonium sulfate did not elicit any significant cytotoxic responses but induced immunomodulatory alterations at very high concentrations. Our findings demonstrate that secondary inorganic components of PM have a lower hazard cytotoxicity compared with combustion-derived and indicative NEE components, and alveolar epithelial cells are more sensitive to PM exposure. This information should help to inform which sources of PM to target and feed into improved, targeted air quality guidelines.

Health and Economic Impact Estimation of Ambient Air Particulate Matter (PM2.5) Pollution in Addis Ababa Using BenMAP-CE Model

Exposure to ambient air particulate matter (PM2.5) pollution presents a significant public health and economic challenge in Addis Ababa, Ethiopia. This thesis used the Environmental benefits mapping and analysis program-community edition (BenMAP-CE) software tool to estimate health and economic impact of ambient air PM2.5 pollution. The study evaluated the impact of decreasing the annual average PM2.5 concentration in 2019 (32.8 µg/m3) to different international and national air quality standards, including World health Organization's guidelines and the Ethiopian National Ambient Air Quality standard (NAAQS). Results showed that Addis Ababa exceeded both WHO's and Ethiopia's ambient air quality standards in 2019. The study estimated the attributable deaths from cardiovascular, ischemic heart disease (IHD), stroke, chronic obstructive pulmonary disease (COPD), and lower respiratory infection (LRI) due to PM2.5 exposure across 3 reduction scenarios. Additionally, economic benefits associated with avoided deaths were quantified using the Organization for Economic Cooperation and Development (OECD) Value of Statistical Life (VSL) methodology. The finding demonstrated that reducing PM2.5 pollution levels led to a notable decrease in mortality rates from various health conditions in Addis Ababa. Moreover substantial economic benefits, amounting to millions of dollars, were observed across all health endpoints, indicating significant societal savings. This study underscores the importance of implementing interventions to mitigate PM2.5 pollution for improved public health and economic well-being in Addis Ababa and similar urban settings.

Reliea® combination of Codonopsis lanceolata and Chaenomeles sinensis extract alleviates airway inflammation on particulate matter 10 plus diesel exhaust particles (PM10D) ‑induced respiratory disease mouse model

Particulate matter (PM, diameter < 10 μm) and Diesel exhaust particles (DEP) exposure can cause severe respiratory disorders. This investigation explored the protective effects of Reliea® (RelA), combination of Codonopsis lanceolata and Chaenomeles sinensis extract, against airway inflammation related to PM10D exposure. RelA treatment suppressed reactive oxygen species, nitric oxide release, cytokine expression (IL-6, IL-1β, iNOS, CXCL-2, MCP-1, and TNF-α), and the related inflammatory mechanisms in PM10-induced alveolar macrophage cells. BALB/c mice were injected with PM10D via intranasal trachea three times over a period of 12 days and RelA were orally dispensed for 12 days. RelA inhibited infiltrating neutrophils, total number of immunocytes in lung and bronchoalveolar lavage fluid (BALF). RelA decreased the expression of interleukin (IL)-17, chemokine (C-X-C motif) ligand (CXCL)-1, thymus and activation-regulated chemokine, macrophage inflammatory protein-2, IL-1α, TNF-α, mucin 5AC, cyclooxygenase-2, and transient receptor potential cation channel subfamily A or V member 1 in BALF and lung, and inhibited IL-1α and macrophage marker F4/80 localization in lung of PM10D-induced mice. RelA treatment decreased serum symmetric dimethyl arginine levels. RelA restored histopathological damage via inhibition of NF-κB and MAPK pathways in the trachea and lung. Lancemaside A and protocatechuic acid as major active compounds of RelA was identified. In addition, RelA showed better expectoration through increased phenol red secretion. These results indicate that Reliea® combination of C. lanceolata and C. sinensis extract might be effective in prevention and treatment of airway inflammation and respiratory diseases.

Triboelectric Nanogenerators for Self-Powered Degradation of Chemical Pollutants

Environmental and human health is severely threatened by wastewater and air pollution, which contain a broad spectrum of organic and inorganic pollutants. Organic contaminants include dyes, volatile organic compounds (VOCs), medical waste, antibiotics, pesticides, and chemical warfare agents. Inorganic gases such as CO2, SO2, and NO x are commonly found in polluted water and air. Traditional methods for pollutant removal, such as oxidation, physicochemical techniques, biotreatment, and enzymatic decomposition, often prove to be inefficient, costly, or energy-intensive. Contemporary solutions like nanofiber-based filters, activated carbon, and plant biomass also face challenges such as generating secondary contaminants and being time-consuming. In this context, triboelectric nanogenerators (TENGs) are emerging as promising alternatives. These devices harvest ambient mechanical energy and convert it to electrical energy, enabling the self-powered degradation of chemical pollutants. This Review summarizes recent progress and challenges in using TENGs as self-powered electrochemical systems (SPECs) for pollutant degradation via photocatalysis or electrocatalysis. The working principles of TENGs are discussed, focusing on their structural flexibility, operational modes, and ability to capture energy from low-frequency mechanical stimuli. The Review concludes with perspectives and suggestions for future research in this field, hoping to inspire further interest and innovation in developing TENG-based SPECs, which represent sustainable and eco-friendly solutions for pollutant treatment.

An insight into recent PM1 aerosol light scattering properties and particle number concentration variabilities at the suburban site ATOLL in Northern France

Aerosol particles in the PM1 fraction considerably influence the climate-related effects of aerosols and impact human health despite representing very variable fractions of the total aerosol mass concentration. Aerosol optical measurement techniques (aerosol light scattering) may not be sufficiently effective for detecting all particles in the PM1 fraction, particularly regarding number concentration. The present study investigates temporal variations of aerosol light scattering properties and particle number concentration (PNC) at different size modes in the PM1 fraction at the atmospheric site ATOLL (The Atmospheric Observations in Lille), Northern France from January 2018 to February 2023. The total scattering coefficient σsp decreased annually by 6 % and 8 % at 525 and 635 nm, respectively. Maximum annual changes occur in winter and summer seasons with a decrease above 10 % per year. Although the backscattering coefficient (σbsp) at 525 nm significantly decreased in winter, this did not result in a significant overall decline over time. Despite a decrease in aerosol light scattering, PNC exhibited a notable annual increase in concentration of N20-30 nm and N30-60 nm, which led to an increase in the total N20-800 nm size range. N20-30nm increased by 10 % annually, with the highest increase by 37 % in spring. Both traffic and photooxidative processes influenced PNCs, underscoring the need for a more comprehensive investigation of the detailed particle number size distribution to assess air quality and the health effects of increased ultrafine PNC at urban/suburban sites in Europe.

Impact of PM2.5 filter extraction solvent on oxidative potential and chemical analysis

Fine particulate matter (PM2.5) is hypothesized to induce oxidative stress, and has been linked to acute and chronic adverse health effects. To better understand the risks and underlying mechanisms following exposure, PM2.5 is collected onto filters but prior to toxicological analysis, particles must be removed from filters. There is no standard method for filter extraction, which creates the possibility that the methods of extraction selected can alter the chemical composition and ultimately the biological implications. In this study, comparisons were made between extraction solvents (methanol (MeOH), dichloromethane (DCM), 0.9% saline, and Milli-Q water) and the results of oxidative potential and elemental concentration analysis of PM2.5 collected across sites in Arkansas, USA. Significant differences were observed between solvents, with DCM having significantly different results compared to all other extraction solvents (p ≤ 0.001). Significant correlations between element, black carbon, and PM2.5 concentrations and oxidative potential were observed. The observed correlations were extraction solvent dependent. For example, in saline extracted samples, oxidative potential had significant negative correlations with: Ba, Cd, Ce, Co, Ga, Mn and significant positive correlations with: Cr, Ni, Th, U. While in MeOH extracted samples, significant positive correlations were only between oxidative potential and Ga, U and significant negative correlations with V. This indicates that PM2.5 samples extracted with different solvents will yield different conclusions about the causal components. This study highlights the importance of filter extraction methods in interpretation of oxidative potential results and comparisons between studies.Implications: While there is no standard method for PM2.5 filter extraction, variation of extraction methods impact analytical results. This project identifies that extraction method variation, particularly extraction solvent selection, leads to discrepancies in chemical and toxicological analysis for PM2.5 collected on the same filter. This work highlights the need for methods standardization to support accurate comparisons between PM2.5 research studies, thus providing better understanding of PM2.5 across the globe.

The declining effectiveness of air quality index in China: A perspective of air pollution alert system

Since 2013, the air quality in China has improved dramatically. However, the regulatory standard as defined in air quality index (AQI) is still the one introduced in 2012. To evaluate the gap between reality and regulation, we study the effectiveness of China's AQI from the perspective of air pollution alert, a system that reflects AQI standard directly. Specifically, based on the respiratory hospitalization data in Chengdu and three models for potential nonlinearity between air pollution and hospitalization, we assess the percentages of hospitalization that can get alerted by the different categories of AQI. We find that while the total hospitalization due to air pollution declined fast due to reduced air pollution, the percentages of hospitalization that can get alerted by different categories of AQI declined faster, resulting in an AQI system that is progressively less binding and effective. Further, we show that a counterfactual tighter standard will bring China's AQI standard closer to international ones, and reverse AQI's declining effectiveness.

Downregulation of tRNA methyltransferase FTSJ1 by PM2.5 promotes glycolysis and malignancy of NSCLC via facilitating PGK1 expression and translation

Fine particulate matter (PM2.5) exposure has been associated with increased incidence and mortality of lung cancer. However, the molecular mechanisms underlying PM2.5 carcinogenicity remain incompletely understood. Here, we identified that PM2.5 suppressed the expression of tRNA methyltransferase FTSJ1 and Am modification level of tRNA in vitro and in vivo. FTSJ1 downregulation enhanced glycolytic metabolism of non-small cell lung cancer (NSCLC) cells, as indicated by increased levels of lactate, pyruvate, and extracellular acidification rate (ECAR). Whereas treatment with glycolytic inhibitor 2-DG reversed this effect. In contrast, upregulation of FTSJ1 significantly suppressed glycolysis of NSCLC cells. Mechanistically, the silencing of FTSJ1 increased NSCLC cell proliferation and glycolysis through enhancing the expression and translation of PGK1. In human NSCLC tumor samples, FTSJ1 expression was negatively correlated with PGK1 expression level and the SUVmax value of PET/CT scan. In summary, our work reveals a previously unrecognized function of PM2.5-downregulated FTSJ1 on PGK1-mediated glycolysis in NSCLC, suggesting that targeted upregulation of FTSJ1 may represent a potential therapeutic strategy for NSCLC.

Chlorophyll-Inspired Magnesium Porphyrin Array Membrane for Vis-Light-Enhanced Osmotic Energy Conversion

Osmotic energy, a renewable clean energy, can be directly converted into electricity through ion-selective membranes. Inspired by the magnesium porphyrin (MgP) in plant chlorophyll, which absorbs vis-light and promotes photoelectric conversion, we demonstrate a MgP array membrane, realizing vis-light-enhanced ion transport regulation ability and osmotic energy conversion. The MgP arrays are self-assembled by a MgP-cored block copolymer under the coordination effect of block copolymer self-assembly and MgP π-π stacking, providing chloride-selective transport channels. Due to the unique photochemical properties of MgP, the chloride ion transport conductance and selectivity can be simultaneously increased under visible-light irradiation, benefiting the osmotic energy conversion. Specifically, the maximum power density increases from 26.7 to 34.5 W·m-2 after visible-light illumination, representing approximately a 30% increase. The construction of MgP arrays realizes photofacilitated osmotic energy conversion, providing an idea for designing an efficient photoelectric conversion system.

Association of Socio-Environmental Burden and Inequality With Cancer Screening and Mortality

BACKGROUND AND OBJECTIVES

Social and environmental injustice may influence accessibility and utilization of health resources, affecting outcomes of patients with cancer. We sought to assess the impact of socio-environmental inequalities on cancer screening and mortality rates for breast, colon, and cervical cancer.

METHODS

Data on cancer screening and environmental justice index social and environmental ranking (SER) was extracted from the CDC PLACES and ATSDR, respectively. Mortality rates were extracted using CDC WONDER. Screening targets were defined by Healthy People 2030.

RESULTS

Among census tracts, 14 659 were classified as "low," 29 534 as "moderate," and 15 474 as "high" SER (high SER denoting greater socioenvironmental injustice). Screening targets were achieved by 31.1%, 16.2%, and 88.6% of tracts for colon, breast, and cervical cancers, respectively. High SER tracts were much less likely to reach screening targets compared with low SER tracts for colon (OR: 0.06), breast (OR: 0.24), and cervical cancer (OR: 0.05) (all p < 0.001). Median mortality rates for low and high SER were 16.7, and 21.0, respectively, for colon, 13.4, 14.75, respectively, for breast, and 1.0, 1.6, respectively, for cervical cancer (all p < 0.05).

CONCLUSION

Socioenvironmental disparities negatively influence cancer screening and mortality, underscoring the need to reduce environmental injustices through measures like equitable cancer screening services.

Performance of fine particulate matter data on air quality in an epidemiological study in Salvador, Brazil

OBJECTIVE

To evaluate the performance of satellite-derived PM2.5 concentrations against ground-based measurements in the municipality of Salvador (state of Bahia, Brazil) and the implications of these estimations for the associations of PM2.5 with daily non-accidental mortality.

METHODS

This is a daily time series study covering the period from 2011 to 2016. A correction factor to improve the alignment between the two data sources was proposed. Effects of PM2.5 were estimated in Poisson generalized additive models, combined with a distributed lag approach.

RESULTS

According to the results, satellite data underestimated the PM2.5 levels compared to ground measurements. However, the application of a correction factor improved the alignment between satellite and ground-based data. We found no significant differences between the estimated relative risks based on the corrected satellite data and those based on ground measurements.

CONCLUSION

In this study we highlight the importance of validating satellite-modeled PM2.5 data to assess and understand health impacts. The development of models using remote sensing to estimate PM2.5 allows the quantification of health risks arising from the exposure.

Removal of airborne particulate matter by evergreen tree species in Dhaka, Bangladesh

Urban air quality stands as a pressing concern in cities globally, with airborne particulate matter (PM) emerging as a significant threat to human health. An investigation was carried out to examine the potential of four prevalent evergreen roadside tree species grown at different locations in Dhaka to capture PM using their leaves. The distribution of PM by mass and quantity in Dhaka are presented for the first time for Bangladesh and these results will also be applicable to countries with similar climates and tree species. Separate gravimetric analyses were carried out to quantify PM in three different size ranges (0.2-2.5 μm, 2.5-10 μm, and 10-100 μm) accumulated on surfaces and trapped within waxes by using the rinse and weigh method. The method is validated for the first time through SEM-EDX analysis, which confirmed that the increase in weight from chloroform-rinsed leaves was exclusively attributable to particle deposition on the filter. The chemical composition of the deposited PM2.5 was analyzed quantitatively by determining the concentration of twenty-five trace elements employing ICP-MS. SEM-EDX analysis revealed the significance of leaf microstructural traits in effectively capturing PM. Significant variations in the deposition of PM were found among different species for two PM categories (surface PM and wax-embedded PM) and three size fractions (large, coarse, and fine) (one-way ANOVA; p < 0.05). The quantity of wax retained on the foliage of trees documented in these locations also varied (p < 0.05). Among the species studied, Ficus benghalensis demonstrated a greater ability to retain PM. Mangifera indica was identified to be the most efficient collector of wax-related PM and appears to be the ideal species for traffic-heavy areas distinguished by high concentrations of organic compounds from vehicle emissions.

Optimizing air quality monitoring spatial layout by maximizing the coverage of the population in Beijing-Tianjin-Hebei and surrounding areas

The spatial layout of the air quality monitoring network (AQMN) is crucial for objective, accurate, and comprehensive air quality assessment. The current technical standard specified the minimum quantity requirements for air quality monitoring sites, but there were no standards to specify the spatial of monitoring sites. This study proposed a novel framework to evaluate and optimize the spatial layout of AQMN. First, this study proposed three indicators to evaluate the performance of the current AQMN. They were monitoring area repetition rate, population coverage rate, and correlations. The assessment of AQMN in Beijing-Tianjin-Hebei and surroundings areas (BTHs) showed the overall monitoring area repetition rate and population coverage rate was 81.07 % and 35.5 %, respectively, which means the current AQMN in BTHs has very high monitoring repeatability and limited population coverage. Secondly, a large-scale linear programming model was built to optimize the spatial layout and determine the spatial location of 279 newly added monitoring sites in BTHs according to the Environmental Monitoring 14th Five-Year Plan of China. The optimization results showed that the optimized AQMN covered 97 million additional people, and the population coverage rate increased to 49.5 %. The proposed framework provided a valuable tool to evaluate and optimize AQMN and could be a potential solution for developing new technical standards of AQMN.

Assessing the Polarising Impacts of Low-Traffic Neighbourhoods: A Community Perspective from Birmingham, UK

Globally, the transport sector is a major contributor to air pollution. Currently, in the UK, vehicle emissions contribute significant amounts of nitrogen oxide (NOx) and particulate matter (PM) pollution in urban areas. Low-emission-zone policies have been used as an intervention to tackle air pollution, and in this context, the UK launched the Low-Traffic Neighbourhood scheme. This study investigates the impacts of the Low-Traffic Neighbourhood in Kings Heath, Birmingham, UK, to evaluate its impact in reducing air pollution and local community perspectives about the scheme and perceived impacts on health and well-being. This study employs a mixed-method approach comprising an air-quality-monitoring assessment and a survey questionnaire involving 210 residents. The findings reveal an increase in active travel and a reduction in air pollution levels in the years after the implementation of the scheme, although the area is still non-compliant with the 2021 WHO air quality guidelines. Nonetheless, the scheme has a polarising effect and created a division within the local community about the overall scheme acceptance and spatial distribution of the scheme's benefits. This study underscores the importance of comprehensive baseline data, long-term community engagement, and integration with broader urban planning initiatives to enhance the success of future Low-Neighbourhood Traffic schemes.

Saharan dust and respiratory health: Understanding the link between airborne particulate matter and chronic lung diseases (Review)

Saharan dust storms, which originate from the Sahara desert, have a significant impact on global health, especially on respiratory conditions of populations exposed to fine particulate matter that travels across continents. Dust events, characterized by the transport of mineral dust such as quartz and feldspar, lead to the suspension of particulate matter in the atmosphere, capable of traversing long distances and affecting air quality adversely. Emerging research links these dust episodes with increased incidence and exacerbation of lung diseases, including asthma and chronic obstructive pulmonary disease, especially during peak dust emission seasons from November to March. The present review aims to synthesize existing scientific evidence concerning the respiratory health impacts of Saharan dust, examining the environmental dynamics of dust transmission, the physical and chemical properties of dust particles, and their biological effects on human health. Further, it assesses epidemiological studies and discusses public health strategies for mitigating adverse health outcomes. Given the complexity of interactions between atmospheric dust particles and respiratory health, this review also highlights critical research gaps that need attention to better understand and manage the health risks associated with Saharan dust.

Co-exposure of ferruginous components of subway particles with lipopolysaccharide impairs vascular function: A comparative study with ambient particulate matter

Several empirical studies have linked subway and ambient particle exposure to toxicity, pro-inflammatory responses, and vascular dysfunction. However, the health effects of pollutants generated from varying sources, particularly when combined with lipopolysaccharide (LPS), are still unexplored. Therefore, the aim of this study was to investigate the characteristic health effects of iron oxide particles (the main components of subway particles) in comparison with urban aerosols (UA) and vehicle exhaust particles (VEP), alone and in combination with LPS. This study revealed that iron oxides caused a more significant reduction in human umbilical vein endothelial cell viability, increased lactate dehydrogenase release, and decreased the production of plasminogen activator inhibitor-1, a fibrinolytic modulator, and endothelin-1, a vasoconstrictor, compared to those by VEP and UA at marginally toxic and toxic concentrations. While VEP and UA induced an increase in interleukin (IL)-6 production, iron oxides, particularly Fe3O4, increased IL-8 production at slightly toxic and non-cytotoxic concentrations. In addition, co-exposure of all particles and LPS at non-cytotoxic concentrations promoted pro-inflammatory cytokine (IL-6 and IL-8) production relative to exposure to the particles alone. Interestingly, the tendency towards either coagulation or fibrinolytic conditions was dependent on the concentration of exposed particles at the same LPS concentration. Furthermore, increases in inflammation, neutrophil and lymphocyte recruitment around blood vessels, and edema were observed in murine lungs exposed to a combination of iron oxides and LPS compared to those in mice exposed to iron oxide alone. Thus, iron oxide-rich subway particulate poses more health risks than outdoor ambient particles since they can significantly impair endothelial function, particularly through gross cellular and vascular homeostatic protein damage, and induce exacerbated inflammatory responses during co-exposure. These findings provide novel empirical evidence for epidemiological studies seeking mechanisms responsible for the observed health impact of transport- and occupational-related exposures on vascular dysfunction.

Health impact of policies to reduce agriculture-related air pollutants in the UK: The relative contribution of change in PM2.5 exposure and diets to morbidity and mortality

Food systems can negatively impact health outcomes through unhealthy diets and indirectly through ammonia emissions originating from agricultural production, which contribute to air pollution and consequently cardiovascular and respiratory health outcomes. In the UK, ammonia emissions from agriculture have not declined in the same way as other air pollutants in recent years. We applied a novel integrated modelling framework to assess the health impacts from six ammonia reduction scenarios to 2030: two agriculture scenarios - a "Current trends" scenario projecting current mitigation measures to reflect a low ambition future, and "High ambition mitigation" based on measures included in the Climate Change Committee's Balanced Pathway to Net Zero; three dietary scenarios - a "Business as usual" based on past trajectories, "Fiscal" applying 20% tax on meat and dairy and 20% subsidy on fruit and vegetables, and "Innovation" applying a 30% switch to plant-based alternatives; one combination of "High ambition mitigation" and "Innovation". Compared to "Current trends", the "High ambition mitigation" scenario would result in a reduction in premature mortality of 13,000, increase life years by 90,000 and reduce incidence of respiratory diseases by 270,000 cases over a 30 year period. Compared to Business as Usual, the dietary scenarios would reduce the number of premature deaths by 65,000 and 550,000-600,000 life years gained over 30 years, with most of the benefits gained by reducing ischemic heart disease (incidence reduction: 190,000). The "High ambition combination" would lead to 67,000 deaths averted, 536,000 incidence reductions and 650,000 life-years gained. For all scenarios, older age groups and those living in lower income households would experience the greatest benefits, because of higher underlying mortality rates or higher levels of risk factors. Our study shows that combining mitigation policies targeting agricultural production systems with diet-related policies would lead to significant reductions in emissions and improvement in health outcomes.

The last decade of air pollution epidemiology and the challenges of quantitative risk assessment

Epidemiologic research and quantitative risk assessment play a crucial role in transferring fundamental scientific knowledge to policymakers so they can take action to reduce the burden of ambient air pollution. This commentary addresses several challenges in quantitative risk assessment of air pollution that require close attention. The background to this discussion provides a summary of and conclusions from the epidemiological evidence on ambient air pollution and health outcomes accumulated since the 1990s. We focus on identifying relevant exposure-health outcome pairs, the associated concentration-response functions to be applied in a risk assessment, and several caveats in their application. We propose a structured and comprehensive framework for assessing the evidence levels associated with each exposure-health outcome pair within a health impact assessment context. Specific issues regarding the use of global or regional concentration-response functions, their shape, and the range of applicability are discussed.