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As policymakers increasingly focus on environmental justice, a key question is whether emissions reductions aimed at addressing air quality or climate change can also ameliorate persistent air pollution exposure disparities. We examine evidence from Californias aggressive vehicle emissions control policy from 2000 to 2019. We find a 65% reduction in modeled statewide average exposure to PM2.5 from on-road vehicles, yet for people of color and overburdened community residents, relative exposure disparities increased. Light-duty vehicle emissions are the main driver of the exposure and exposure disparity, although smaller contributions from heavy-duty vehicles especially affect some overburdened groups. Our findings suggest that a continued trend of emissions reductions will likely reduce concentrations and absolute disparity but may not reduce relative disparities without greater attention to the systemic factors leading to this disparity.

Innate lymphoid cells (ILCs) are a heterogeneous population that play diverse roles in airway inflammation after exposure to allergens and infections. However, how ILCs respond after exposure to environmental toxins is not well understood. Here we show a novel method for studying the heterogeneity of rare lung ILC populations by magnetic enrichment for lung ILCs followed by particle-templated instant partition sequencing (PIP-seq). Using this method, we were able to identify novel group 1 and group 2 ILC subsets that exist after exposure to both fungal allergen and burn pit-related constituents (BPC) that include dioxin, aromatic hydrocarbon, and particulate matter. Toxin exposure in combination with fungal allergen induced activation of specific ILC1/NK and ILC2 populations as well as promoted neutrophilic lung inflammation. Oxidative stress pathways and downregulation of specific ribosomal protein genes (Rpl41 and Rps19) implicated in anti-inflammatory responses were present after BPC exposure. Increased IFNγ expression and other pro-neutrophilic mediator transcripts were increased in BPC-stimulated lung innate lymphoid cells. Further, the addition of BPC induced Hspa8 (encodes HSC70) and aryl hydrocarbon transcription factor activity across multiple lung ILC subsets. Overall, using an airway disease model that develops after occupational and environmental exposures, we demonstrate an effective method to better understand heterogenous ILC subset activation.

Environmentally persistent free radicals (EPFRs) play an important role in aerosol effects on air quality and public health, but their atmospheric abundance and sources are poorly understood. We measured EPFRs contained in PM2.5 collected in Fairbanks, Alaska, in winter 2022. We find that EPFR concentrations were enhanced during surface-based inversion and correlate strongly with incomplete combustion markers, including carbon monoxide and elemental carbon (R2 > 0.75). EPFRs exhibit moderately good correlations with PAHs, biomass burning organic aerosols, and potassium (R2 > 0.4). We also observe strong correlations of EPFRs with hydrocarbon-like organic aerosols, Fe and Ti (R2 > 0.6), and single-particle mass spectrometry measurements reveal internal mixing of PAHs, with potassium and iron. These results suggest that residential wood burning and vehicle tailpipes are major sources of EPFRs and nontailpipe emissions, such as brake wear and road dust, may contribute to the stabilization of EPFRs. Exposure to the observed EPFR concentrations (18 ± 12 pmol m-3) would be equivalent to smoking ∼0.4-1 cigarette daily. Very strong correlations (R2 > 0.8) of EPFR with hydroxyl radical formation in surrogate lung fluid indicate that exposure to EPFRs may induce oxidative stress in the human respiratory tract.

Indonesia faces significant air quality issues due to multiple emissions sources, including rapid urbanization and peatland fires associated with agricultural land management. Limited prior research has estimated the episodic shock of intense fires on morbidity and mortality in Indonesia but has largely ignored the impact of poor air quality throughout the year on biomarkers of cardiovascular disease risk. We conducted a cross-sectional study of the association between particulate matter less than 2.5 microns in diameter (PM2.5) and blood pressure. Blood pressure measurements were obtained from the fifth wave of the Indonesian Family Life Survey (IFLS5), an ongoing population-based socioeconomic and health survey. We used the GEOS-Chem chemical transport model to simulate daily PM2.5 concentrations at 0.5° × 0.625° resolution across the IFLS domain. We assessed the association between PM2.5 and diastolic and systolic blood pressure, using mixed effects models with random intercepts for regency/municipality and household and adjusted for individual covariates. An interquartile range increase in monthly PM2.5 exposure was associated with a 0.234 (95% CI: 0.003, 0.464) higher diastolic blood pressure, with a greater association seen in participants age 65 and over (1.16 [95% CI: 0.24, 2.08]). For the same exposure metric, there was a 1.90 (95% CI: 0.43, 3.37) higher systolic blood pressure in participants 65 and older. Our assessment of fire-specific PM2.5 yielded null results, potentially due to the timing and locations of health data collection. To our knowledge, this is the first study to provide evidence for an association between PM2.5 and blood pressure in Indonesia.

First-ever measurements of particulate matter (PM2.5, PM10, and TSP) along with gaseous pollutants (CO, NO2, and SO2) were performed from June 2019 to April 2020 in Faisalabad, Metropolitan, Pakistan, to assess their seasonal variations; Summer 2019, Autumn 2019, Winter 2019-2020, and Spring 2020. Pollutant measurements were carried out at 30 locations with a 3-km grid distance from the Sitara Chemical Industry in District Faisalabad to Bhianwala, Sargodha Road, Tehsil Lalian, District Chiniot. ArcGIS 10.8 was used to interpolate pollutant concentrations using the inverse distance weightage method. PM2.5, PM10, and TSP concentrations were highest in summer, and lowest in autumn or winter. CO, NO2, and SO2 concentrations were highest in summer or spring and lowest in winter. Seasonal average NO2 and SO2 concentrations exceeded WHO annual air quality guide values. For all 4 seasons, some sites had better air quality than others. Even in these cleaner sites air quality index (AQI) was unhealthy for sensitive groups and the less good sites showed Very critical AQI (> 500). Dust-bound carbon and sulfur contents were higher in spring (64 mg g-1) and summer (1.17 mg g-1) and lower in autumn (55 mg g-1) and winter (1.08 mg g-1). Venous blood analysis of 20 individuals showed cadmium and lead concentrations higher than WHO permissible limits. Those individuals exposed to direct roadside pollution for longer periods because of their occupation tended to show higher Pb and Cd blood concentrations. It is concluded that air quality along the roadside is extremely poor and potentially damaging to the health of exposed workers.

Exposure to ambient air pollution has significant adverse health effects; however, whether air pollution is associated with urological cancer is largely unknown. We conduct a systematic review and meta-analysis with epidemiological studies, showing that a 5 μg/m3 increase in PM2.5 exposure is associated with a 6%, 7%, and 9%, increased risk of overall urological, bladder, and kidney cancer, respectively; and a 10 μg/m3 increase in NO2 is linked to a 3%, 4%, and 4% higher risk of overall urological, bladder, and prostate cancer, respectively. Were these associations to reflect causal relationships, lowering PM2.5 levels to 5.8 μg/m3 could reduce the age-standardized rate of urological cancer by 1.5 ~ 27/100,000 across the 15 countries with the highest PM2.5 level from the top 30 countries with the highest urological cancer burden. Implementing global health policies that can improve air quality could potentially reduce the risk of urologic cancer and alleviate its burden.

BACKGROUND: Numerous studies have linked fine particulate matter (PM2.5) to increased cardiovascular mortality. Less is known how the PM2.5-cardiovascular mortality association varies by use of cardiovascular medications. This study sought to quantify effect modification by statin use status on the associations between long-term exposure to PM2.5 and mortality from any cardiovascular cause, coronary heart disease (CHD), and stroke. METHODS: In this nested case-control study, we followed 1.2 million community-dwelling adults aged ≥66 years who lived in Ontario, Canada from 2000 through 2018. Cases were patients who died from the three causes. Each case was individually matched to up to 30 randomly selected controls using incidence density sampling. Conditional logistic regression models were used to estimate odds ratios (ORs) for the associations between PM2.5 and mortality. We evaluated the presence of effect modification considering both multiplicative (ratio of ORs) and additive scales (the relative excess risk due to interaction, RERI). RESULTS: Exposure to PM2.5 increased the risks for cardiovascular, CHD, and stroke mortality. For all three causes of death, compared with statin users, stronger PM2.5-mortality associations were observed among non-users [e.g. for cardiovascular mortality corresponding to each interquartile range increase in PM2.5, OR = 1.042 (95% CI, 1.032-1.053) vs OR = 1.009 (95% CI, 0.996-1.022) in users, ratio of ORs = 1.033 (95% CI, 1.019-1.047), RERI = 0.039 (95% CI, 0.025-0.050)]. Among users, partially adherent users exhibited a higher risk of PM2.5-associated mortality than fully adherent users. CONCLUSIONS: The associations of chronic exposure to PM2.5 with cardiovascular and CHD mortality were stronger among statin non-users compared to users.

In California, wildfire risk and severity have grown substantially in the last several decades. Research has characterized extensive adverse health impacts from exposure to wildfire-attributable fine particulate matter (PM2.5), but few studies have quantified long-term outcomes, and none have used a wildfire-specific chronic dose-response mortality coefficient. Here, we quantified the mortality burden for PM2.5 exposure from California fires from 2008 to 2018 using Community Multiscale Air Quality modeling system wildland fire PM2.5 estimates. We used a concentration-response function for PM2.5, applying ZIP code-level mortality data and an estimated wildfire-specific dose-response coefficient accounting for the likely toxicity of wildfire smoke. We estimate a total of 52,480 to 55,710 premature deaths are attributable to wildland fire PM2.5 over the 11-year period with respect to two exposure scenarios, equating to an economic impact of $432 to $456 billion. These findings extend evidence on climate-related health impacts, suggesting that wildfires account for a greater mortality and economic burden than indicated by earlier studies.

Wildfires are increasing in duration and intensity across the United States' Pacific West region, resulting in heightened particulate matter from smoke in the atmosphere. Levels of peak particulate matter are concurrent to peak visitor attendance at National Parks, given seasonal alignment with summer vacation travel and heightened forest fire conditions. Particulate matter threatens visitor health and safety and contributes to poor visibility and a deteriorated visitor experience. To assess visitation response to diminished air quality, we utilized wildfire-generated particulate matter (PM2.5) data in conjunction with monthly attendance records for three ecoregions containing eight national parks in Washington, Oregon, and California from 2009 to 2019. We analyzed daily PM2.5 levels from data gridded at the 10 km scale for National Park Service units by Level III forest ecoregions within the National Park Service's Pacific West Unit. Data were then compared to normalized monthly visitation trends for each of the ecoregions using two statistical methods Kendall's Tau and Analysis of Variance (ANOVA) with post-hoc Tukey tests. Results demonstrate that attendance at these national parks does not decrease in response to increased PM2.5 levels. Instead, we see several statistically significant increases in attendance across these ecoregions during periods of reduced air quality. Of 115 shifts between air quality categories during the busy season of July to September, there are no significant decreases in attendance as air quality worsens. These findings suggest that visitors are willing to tolerate reduced air quality compared to other factors such as temperature or precipitation. Given that park units within each ecoregion feature diverse historical contexts, varied built environments, and unique ecological systems, our discussion specifically addresses managerial concerns associated with maintained high levels of visitation during suboptimal, and potentially dangerous, conditions. There is substantial need for specific, scalable approaches to mitigate adverse health and experiential impacts as visitors are exposed to increased risks during a range of exertional activities associated with diverse settings.

We examined associations between prenatal fine particulate matter (PM2.5), nitrogen dioxide (NO2), and ozone (O3) exposures and child respiratory outcomes through age 8-9 years in 1279 ECHO-PATHWAYS Consortium mother-child dyads. We averaged spatiotemporally modeled air pollutant exposures during four fetal lung development phases: pseudoglandular (5-16 weeks), canalicular (16-24 weeks), saccular (24-36 weeks), and alveolar (36+ weeks). We estimated adjusted relative risks (RR) for current asthma at age 8-9 and asthma with recent exacerbation or atopic disease, and odds ratios (OR) for wheezing trajectories using modified Poisson and multinomial logistic regression, respectively. Effect modification by child sex, maternal asthma, and prenatal environmental tobacco smoke was explored. Across all outcomes, 95% confidence intervals (CI) included the null for all estimates of associations between prenatal air pollution exposures and respiratory outcomes. Pseudoglandular PM2.5 exposure modestly increased risk of current asthma (RRadj = 1.15, 95% CI: 0.88-1.51); canalicular PM2.5 exposure modestly increased risk of asthma with recent exacerbation (RRadj = 1.26, 95% CI: 0.86-1.86) and persistent wheezing (ORadj = 1.28, 95% CI: 0.86-1.89). Similar findings were observed for O3, but not NO2, and associations were strengthened among mothers without asthma. While not statistically distinguishable from the null, trends in effect estimates suggest some adverse associations of early pregnancy air pollution exposures with child respiratory conditions, warranting confirmation in larger samples.

BACKGROUND: Epidemiological findings regarding the association of particulate matter ≤2.5 μm (PM2.5) exposure with hypertensive disorders in pregnancy (HDP) are inconsistent; evidence for HDP risk related to PM2.5 components, mixture effects, and windows of susceptibility is limited. We aimed to investigate the relationships between HDP and exposure to PM2.5 during pregnancy. METHODS AND FINDINGS: A large retrospective cohort study was conducted among mothers with singleton pregnancies in Kaiser Permanente Southern California from 2008 to 2017. HDP were defined by International Classification of Diseases-9/10 (ICD-9/10) diagnostic codes and were classified into 2 subcategories based on the severity of HDP: gestational hypertension (GH) and preeclampsia and eclampsia (PE-E). Monthly averages of PM2.5 total mass and its constituents (i.e., sulfate, nitrate, ammonium, organic matter, and black carbon) were estimated using outputs from a fine-resolution geoscience-derived model. Multilevel Cox proportional hazard models were used to fit single-pollutant models; quantile g-computation approach was applied to estimate the joint effect of PM2.5 constituents. The distributed lag model was applied to estimate the association between monthly PM2.5 exposure and HDP risk. This study included 386,361 participants (30.3 ± 6.1 years) with 4.8% (17,977/373,905) GH and 5.0% (19,381/386,361) PE-E cases, respectively. In single-pollutant models, we observed increased relative risks for PE-E associated with exposures to PM2.5 total mass [adjusted hazard ratio (HR) per interquartile range: 1.07, 95% confidence interval (CI) [1.04, 1.10] p < 0.001], black carbon [HR = 1.12 (95% CI [1.08, 1.16] p < 0.001)] and organic matter [HR = 1.06 (95% CI [1.03, 1.09] p < 0.001)], but not for GH. The population attributable fraction for PE-E corresponding to the standards of the US Environmental Protection Agency (9 μg/m3) was 6.37%. In multi-pollutant models, the PM2.5 mixture was associated with an increased relative risk of PE-E ([HR = 1.05 (95% CI [1.03, 1.07] p < 0.001)], simultaneous increase in PM2.5 constituents of interest by a quartile) and PM2.5 black carbon gave the greatest contribution of the overall mixture effects (71%) among all individual constituents. The susceptible window is the late first trimester and second trimester. Furthermore, the risks of PE-E associated with PM2.5 exposure were significantly higher among Hispanic and African American mothers and mothers who live in low- to middle-income neighborhoods (p < 0.05 for Cochrans Q test). Study limitations include potential exposure misclassification solely based on residential outdoor air pollution, misclassification of disease status defined by ICD codes, the date of diagnosis not reflecting the actual time of onset, and lack of information on potential covariates and unmeasured factors for HDP. CONCLUSIONS: Our findings add to the literature on associations between air pollution exposure and HDP. To our knowledge, this is the first study reporting that specific air pollution components, mixture effects, and susceptible windows of PM2.5 may affect GH and PE-E differently.

Wildfires are a significant threat to human health, in part through degraded air quality. Prescribed burning can reduce wildfire severity but can also lead to an increase in air pollution. The complexities of fires and atmospheric processes lead to uncertainties when predicting the air quality impacts of fire and make it difficult to fully assess the costs and benefits of an expansion of prescribed fire. By modeling differences in emissions, surface conditions, and meteorology between wildfire and prescribed burns, we present a novel comparison of the air quality impacts of these fire types under specific scenarios. One wildfire and two prescribed burn scenarios were considered, with one prescribed burn scenario optimized for potential smoke exposure. We found that PM2.5 emissions were reduced by 52%, from 0.27 to 0.14 Tg, when fires burned under prescribed burn conditions, considerably reducing PM2.5 concentrations. Excess short-term mortality from PM2.5 exposure was 40 deaths for fires under wildfire conditions and 39 and 15 deaths for fires under the default and optimized prescribed burn scenarios, respectively. Our findings suggest prescribed burns, particularly when planned during conditions that minimize smoke exposure, could be a net benefit for the impacts of wildfires on air quality and health.

We investigated the relationship between porosity and flexoelectricity for aluminum (Al)/polyvinylidene fluoride (PVDF) composites. Neat PVDF, composites of micron aluminum (μAl)/PVDF, and composites of nano aluminum (nAl)/PVDF were 3D printed, and the flexoelectric response was measured using a cantilever beam test setup. Voids (up to 72.4 mm3) were incorporated into the samples by decreasing the infill percent of the 3D printed material. We found that increasing the porosity via millimeter scale voids incorporated into the infill pattern decreased the average effective flexoelectric coefficient relative to the near full-density (100% infill) control samples. This contrasts with other studies that have shown increasing micron scale porosity increases the flexoelectric coefficient. In addition, we measured higher flexoelectric responses for nAl/PVDF than μAl/PVDF as well as for samples printed by the Hyrel 3D SR printer as opposed to the Ender 3 V2 printer. These results indicate that charge generation due to flexoelectricity can be altered by changing parameters such as porosity, particle size of inclusions, or manufacturing method. Smaller voids and fine particles can induce larger strain gradients than larger inhomogeneities, leading to increased flexoelectric coefficients. A competing effect is that more porosity leads to less materials, which can decrease the flexoelectric coefficient. [ABSTRACT FROM AUTHOR]

Wildfires have become more frequent and intense due to climate change and outdoor wildfire fine particulate matter (PM2.5) concentrations differ from relatively smoothly varying total PM2.5. Thus, we introduced a conceptual model for computing long-term wildfire PM2.5 and assessed disproportionate exposures among marginalized communities. We used monitoring data and statistical techniques to characterize annual wildfire PM2.5 exposure based on intermittent and extreme daily wildfire PM2.5 concentrations in California census tracts (2006 to 2020). Metrics included: 1) weeks with wildfire PM2.5 < 5 μg/m3; 2) days with non-zero wildfire PM2.5; 3) mean wildfire PM2.5 during peak exposure week; 4) smoke waves (≥2 consecutive days with

BACKGROUND: In contrast to fine particles, less is known of the inflammatory and coagulation impacts of coarse particulate matter (PM10-2.5, particulate matter with aerodynamic diameter ≤10μm and>2.5μm). Toxicological research suggests that these pathways might be important processes by which PM10-2.5 impacts health, but there are relatively few epidemiological studies due to a lack of a national PM10-2.5 monitoring network. OBJECTIVES: We used new spatiotemporal exposure models to examine associations of both 1-y and 1-month average PM10-2.5 concentrations with markers of inflammation and coagulation. METHODS: We leveraged data from 7,071 Multi-Ethnic Study of Atherosclerosis and ancillary study participants 45-84 y of age who had repeated plasma measures of inflammatory and coagulation biomarkers. We estimated PM10-2.5 at participant addresses 1 y and 1 month before each of up to four exams (2000-2012) using spatiotemporal models that incorporated satellite, regulatory monitoring, and local geographic data and accounted for spatial correlation. We used random effects models to estimate associations with interleukin-6 (IL-6), C-reactive protein (CRP), fibrinogen, and D-dimer, controlling for potential confounders. RESULTS: Increases in PM10-2.5 were not associated with greater levels of inflammation or coagulation. A 10-μg/m3 increase in annual average PM10-2.5 was associated with a 2.5% decrease in CRP [95% confidence interval (CI): -5.5, 0.6]. We saw no association between annual average PM10-2.5 and the other markers (IL-6: -0.7%, 95% CI: -2.6, 1.2; fibrinogen: -0.3%, 95% CI: -0.9, 0.3; D-dimer: -0.2%, 95% CI: -2.6, 2.4). Associations consistently showed that a 10-μg/m3 increase in 1-month average PM10-2.5 was associated with reduced inflammation and coagulation, though none were distinguishable from no association (IL-6: -1.2%, 95% CI: -3.0 , 0.5; CRP: -2.5%, 95% CI: -5.3, 0.4; fibrinogen: -0.4%, 95% CI: -1.0, 0.1; D-dimer: -2.0%, 95% CI: -4.3, 0.3). DISCUSSION: We found no evidence that PM10-2.5 is associated with higher inflammation or coagulation levels. More research is needed to determine whether the inflammation and coagulation pathways are as important in explaining observed PM10-2.5 health impacts in humans as they have been shown to be in toxicology studies or whether PM10-2.5 might impact human health through alternative biological mechanisms. https://doi.org/10.1289/EHP12972.

Future climate change can cause more days with poor air quality. This could trigger more alerts telling people to stay inside to protect themselves, with potential consequences for health and health equity. Here, we study the change in US air quality alerts over this century due to fine particulate matter (PM2.5), who they may affect, and how they may respond. We find air quality alerts increase by over 1 mo per year in the eastern United States by 2100 and quadruple on average. They predominantly affect areas with high Black populations and leakier homes, exacerbating existing inequalities and impacting those less able to adapt. Reducing emissions can offer significant annual health benefits ($5,400 per person) by mitigating the effect of climate change on air pollution and its associated risks of early death. Relying on people to adapt, instead, would require them to stay inside, with doors and windows closed, for an extra 142 d per year, at an average cost of $11,000 per person. It appears likelier, however, that people will achieve minimal protection without policy to increase adaptation rates. Boosting adaptation can offer net benefits, even alongside deep emission cuts. New adaptation policies could, for example: reduce adaptation costs; reduce infiltration and improve indoor air quality; increase awareness of alerts and adaptation; and provide measures for those working or living outdoors. Reducing emissions, conversely, lowers everyones need to adapt, and protects those who cannot adapt. Equitably protecting human health from air pollution under climate change requires both mitigation and adaptation.

Wildfires are a global natural phenomenon. In North America, wildfires have not only become more frequent, but also more severe and longer in duration, a trend ascribed to climate change combined with large fuel stores left from modern fire suppression. The intensification of wildfire activity has significant implications for planetary health and public health, as exposure to fine particulate matter (PM2.5) in wildfire smoke is linked to adverse health effects. This review focuses on respiratory morbidity from wildfire smoke exposure. Inhalation of wildfire PM2.5 causes lung injury via oxidative stress, local and systemic inflammation, airway epithelium compromise, and increased vulnerability to infection. Wildfire PM2.5 exposure results in exacerbations of pre-existing asthma and chronic obstructive pulmonary disease, with an escalation in healthcare utilization, including emergency department visits and hospitalizations. Wildfire smoke exposure may be associated with asthma onset, long-term impairment of lung function, and increased all-cause mortality. Children, older adults, occupationally-exposed groups, and possibly women are the most at risk from wildfire smoke. Future research is needed to clarify best practices for risk mitigation and wildfire management.

BackgroundPrior studies suggested that air pollution exposure may increase the risk of Parkinson's Disease (PD). We investigated the long-term impacts of traffic-related and multiple sources of particulate air pollution on PD in central California.MethodsOur case-control analysis included 761 PD patients and 910 population controls. We assessed exposure at residential and occupational locations from 1981 to 2016, estimating annual average carbon monoxide (CO) concentrations - a traffic pollution marker - based on the California Line Source Dispersion Model, version 4. Additionally, particulate matter (PM2.5) concentrations were based on a nationwide geospatial chemical transport model. Exposures were assessed as 10-year averages with a 5-year lag time prior to a PD diagnosis for cases and an interview date for controls, subsequently categorized into tertiles. Logistic regression models were used, adjusting for various factors.ResultsTraffic-related CO was associated with an increased odds ratio for PD at residences (OR for T3 vs. T1: 1.58; 95% CI: 1.20, 2.10; p-trend = 0.02) and workplaces (OR for T3 vs. T1: 1.91; 95% CI: 1.22, 3.00; p-trend

Detection sensitivity of aquatic species using environmental DNA (eDNA) generally decreases in turbid water but is poorly characterized. In this study, eDNA detection targeted delta smelt (Hypomesus transpacificus), a critically endangered estuarine fish associated with turbid water. eDNA sampling in the field was first paired with a trawl survey. Species-specific detection using a Taqman qPCR assay showed concordance between the methods, but a weak eDNA signal. Informed by the results of field sampling, an experiment was designed to assess how turbidity and filtration methods influence detection of a rare target. Water from non-turbid (5 NTU) and turbid (50 NTU) estuarine sites was spiked with small volumes (0.5 and 1 mL) of water from a delta smelt tank to generate low eDNA concentrations. Samples were filtered using four filter types: cartridge filters (pore size 0.45 μm) and 47 mm filters (glass fiber, pore size 1.6 μm and polycarbonate, pore sizes 5 and 10 μm). Prefiltration was also tested as an addition to the filtration protocol for turbid water samples. eDNA copy numbers were analyzed using a censored data method for qPCR data. The assay limits and lack of PCR inhibition indicated an optimized assay. Glass fiber filters yielded the highest detection rates and eDNA copies in non-turbid and turbid water. Prefiltration improved detection in turbid water only when used with cartridge and polycarbonate filters. Statistical analysis identified turbidity as a significant effect on detection probability and eDNA copies detected; filter type and an interaction between filter type and prefilter were significant effects on eDNA copies detected, suggesting that particulate-filter interactions can affect detection sensitivity. Pilot experiments and transparent criteria for positive detection could improve eDNA surveys of rare species in turbid environments.

Currently, the problem of air pollution is getting more and more serious, especially the pollution of tiny solid particles (PM, particulate matter) in the air, which poses a great challenge to the environment and human health. Therefore, it is particularly important to develop air filtration materials with high filtration efficiency and low resistance to meet this challenge. In this study, we propose to prepare air filtration membranes by centrifugal jet electrospinning technology, design multifactorial orthogonal coupling experiments, and investigate the effects of key process parameters of centrifugal jet electrostatic spinning, including solution concentration, airflow rate, rotational speed, and voltage, on the fiber diameter and uniformity by applying the polar analysis of variance and analysis of variance. PAN‐BaTiO3 electret nanofiber filtration membranes with high efficiency and low resistance were prepared by combining the optimized process of centrifugal blowing electrospinning. Various characterization methods (tensile test, water contact angle test, surface charge test, filtration test) were used to evaluate the effect of different BaTiO3 electret contents (0%, 0.1%, 0.5%, 1%) on the comprehensive performance of the filtration membranes, and the electret filtration efficiency of the electret filtration membranes prepared by the present process reached as high as 96.56% with a pressure drop of 29 Pa. [ABSTRACT FROM AUTHOR]

The document is a contents list from the journal CrystEngComm, focusing on the design and understanding of solid-state and crystalline materials. It includes highlights, communications, papers, and information on various research topics such as metal-organic frameworks, crystal growth, and hydrogen storage. The journal aims to connect the world with the chemical sciences and invest profits back into the chemistry community, showcasing a diverse range of scientific research in the field. [Extracted from the article]

Octacalcium phosphate (OCP) is a fascinating calcium phosphate material with a layered structure that can incorporate various guest molecules, particularly dicarboxylate ions. However, the solution-phase synthesis of OCP fine particles is challenging. In this study, we developed a new precipitation method based on the LaMer model for synthesising fine particles of plain OCP and OCP with incorporated isophthalate and succinate ions. Highly concentrated aqueous solutions and appropriate reaction conditions yielded particle sizes of 100–200 nm for plain OCP and 200–300 nm for OCP with incorporated dicarboxylate ions. The obtained particle sizes were significantly smaller than those of OCPs synthesised using conventional methods. The incorporation of isophthalate and succinate ions into OCP was confirmed using various methods, particularly X-ray diffraction, which revealed expansion of the (100) interplanar spacing. During the synthesis of OCP with incorporated isophthalate ions, hydrolysis of the OCP phase was minimised when the initial pH range of the isophthalic acid solution was 5.2–5.3. Interestingly, OCP with incorporated isophthalate ions exhibited fluorescence (excitation and emission at 325 and 390 nm, respectively), demonstrating the potential of these fine particles as novel biofriendly fluorescent probes. This novel LaMer-model-based synthesis for preparing fine particles of OCP and OCP with incorporated functional carboxylate ions can contribute to the design and development of next-generation biofriendly imaging probes and other functional calcium phosphate materials, such as for use in biosensing and drug delivery applications. [ABSTRACT FROM AUTHOR]

Background: Particulate matter consisting of fine particles measuring 2.5 microns or less in diameter (PM2.5), a component of air pollution, has been linked to adverse health outcomes. The objective of this study was to assess the association between ambient PM2.5 exposure and survival in children with cancer in the United States. Methods: Individuals aged birth to 19 years who were diagnosed with cancer between January 1, 2004, and December 31, 2019, were selected from the National Cancer Database. The association between the annual PM2.5 level at the patient's zip code of residence at the time of diagnosis and overall survival was evaluated using time‐varying Cox proportional hazards models (crude and adjusted for diagnosis year and age). To address concerns that exposure to air pollution is correlated with other social determinants of health, the authors tested the association between PM2.5 levels and survival among sociodemographic subgroups. Results: Of the 172,550 patients included, 27,456 (15.9%) resided in areas with annual PM2.5 concentrations above the US Environmental Protection Agency (EPA) annual PM2.5 standard of 12 μg/m3. Residing in these high‐pollution areas was associated with worse overall survival (adjusted hazard ratio [aHR], 1.06; 95% confidence interval [CI], 1.012–1.10). Similarly, when PM2.5 was evaluated as a linear measure, each unit increase in PM2.5 exposure was associated with worse survival (aHR, 1.011; CI, 1.005–1.017). Exposure to PM2.5 at levels above the EPA standards was also significantly associated with worse overall survival among sociodemographic subgroups. Conclusions: Exposure to PM2.5 was significantly associated with worse overall survival among children with cancer, even at levels below EPA air quality standards. These results underscore the importance of setting appropriate air quality standards to protect the health of this sensitive population. Plain Language Summary: The authors investigated how living in areas with high air pollution (defined as particulate matter consisting of fine particles measuring 2.5 microns or less in diameter; PM2.5) affects the overall survival of children with cancer in the United States.The results indicated that children living in areas with higher PM2.5 levels, and even at levels below prior and current US Environmental Protection Agency standards, had lower survival rates than children living in areas with lower levels of PM2.5.This finding emphasizes the need for stricter air quality standards to better protect children, particularly those with serious health conditions like childhood cancer. Exposure to particulate matter consisting of fine particles less than or equal to 2.5 microns in diameter was significantly associated with worse overall survival in children with cancer, even at levels below US Environmental Protection Agency air quality standards. These findings highlight the need for stricter air quality regulations to protect vulnerable populations. [ABSTRACT FROM AUTHOR]

In indoor environments, air quality significantly impacts human health and well-being, with carbon monoxide (CO) posing a particular hazard due to its colorless and odorless nature and potential to cause severe health issues. Integrating the Internet of Things and remote sensing technologies has revolutionized data monitoring, collection, and evaluation, especially within the context of 'smart' homes. This study leverages these technologies to enhance indoor air quality monitoring. By collecting data on key indoor atmospheric quality indicators—carbon dioxide (CO2), methane (CH4), alcohol, liquefied petroleum gas (LPG), particulate matter (PM1 and PM2.5), humidity, and temperature—the study aims to predict indoor carbon monoxide levels. A custom dataset was compiled from August to October, consisting of 61,710 observations recorded at one-minute intervals. The methodology employs a stacking ensemble approach, integrating multiple machine learning models to boost prediction accuracy and reliability. In the stacking ensemble, six distinct models are employed: Random Forest, Multi-Layer Perceptron, Lasso, Elastic Net, XGBoost, and Support Vector Regression. Each model is individually trained and fine-tuned using the Grid Search method to optimize parameter combinations. These optimized models are then combined in the stacking ensemble, which achieves a Mean Squared Error (MSE) of 0.0140, a Root Mean Squared Error (RMSE) of 0.1185, and a Mean Absolute Error (MAE) of 0.0291. The results demonstrate that the proposed system significantly enhances the precision of CO prediction, underscoring its critical role in air quality surveillance within smart environments. [ABSTRACT FROM AUTHOR]

Air pollution is one of the main public health and safety issues facing humanity. PM2.5 concentration prediction (PCP) helps the public to prevent and make government decisions in advance. PCP is a typical knowledge mining problem based on spatiotemporal sequential data, which still faces great challenges up to now. Aiming at the complex conundrum of meteorological, geographical, and temporal factors interference and concentration sudden changes, a dynamic spatiotemporal graph neural network (DST_GNN) method for PCP is proposed by using the advantages of graph neural network (GNN) and mechanism model. Its main methods are: The graph structure is used to construct the spatial relationship of PM2.5 among different monitoring stations, the mechanism model HYSPLIT is used to construct the dynamic edge relationship among graph nodes, and the gate recurrent unit of attention mechanism is used to learn the timing of PM2.5 concentration, thus forming a GNN architecture that integrates machine learning and domain knowledge. In addition, a loss function based on trend and shape is proposed when the model objective function is designed. The proposed model innovatively uses HYSPLIT to assist in building a dynamic spatiotemporal graph network and uses trend loss function for model training, which provides a new way for the dynamic construction of GNN, and provides a reference for PCP by combining domain knowledge and deep learning. Experimental results show that the proposed method has the best prediction accuracy among GNN based methods, which reduced the mean absolute error by about 14% and root mean square error by about 13% compared with the advanced GNN methods. The mean absolute error within 48 h forecast is less than 50, which predictive performance is far superior to the traditional mechanism model, and it also has the characteristics of flexible deployment and easy implementation. [ABSTRACT FROM AUTHOR]

To clarify the influence of H2O thermal effect on the formation of ultrafine particulate matter (PM), Huangling coal char was burned in a high-temperature drop tube furnace at 1800 K under various O2/N2/H2O and O2/N2/H2O/Ar atmospheres. The introduction of Ar in the simulating atmosphere was designed to counteract the thermal effect of H2O. Results indicated that after eliminating the thermal effect of H2O, the yield of ultrafine PM continuously increased in higher H2O content. Compared with no H2O, the mass and number yield of ultrafine PM in O2/N2/H2O/Ar atmosphere with 30% H2O content increased by 35.5% and 58.9%, respectively. H2O thermal effect, gasification reaction, and char oxidation reaction during coal char combustion played a significant role in the formation of ultrafine PM. Oxidation reaction was the primary factor affecting the formation of ultrafine PM, and its relative contribution was more than 62.9%, whereas the thermal effect of H2O showed an overall negative net effect on the formation of ultrafine PM. With the H2O content varied from 5% to 30%, the contribution of H2O thermal effect to mass yield was in the range of −19.1% to −18.0%, while that to number yield was −33.1% to −30.6%. Once the H2O content reached 10%, the enhancing effect of H2O gasification reaction on the yield of ultrafine PM surpassed the negative contribution of H2O thermal effect. For a given H2O content, elevated O2 concentration weakened the negative contribution of H2O thermal effect. [ABSTRACT FROM AUTHOR]

ABSTRACT Particulate matter (PM) is one of the most important air pollutants that can hurt human health. Fireworks are rare but important sources of ambient PM and can therefore lead to short‐term exposure to high concentrations of PM with potentially toxic components. For the first time in the city of Rijeka, Croatia, the characteristics of fireworks PM during 6 celebrations (New Year 2015, 2017, and 2018 and 3 football events in May 2017) were investigated and compared with the average concentrations during the surrounding period. The elemental composition of the PM samples was determined using the X‐ray fluorescence technique, where the concentrations of 15 elements from S to Pb were determined. Although the total PM concentrations were in the range of values previously measured at the same locations, the concentrations of several elements were substantially larger during the fireworks. A significant increase in concentrations was observed for K, Ti, Cr, Cu, Sr, and Ba, with the largest increase in concentration for Sr and Ba. The most noticeable increase in concentrations compared to the seasonal average was observed during the 2018 New Year's sampling when the average 8‐h concentrations were elevated as follows: 11 times for K, 14 times for Ti, 5 times for Cr, 9 times for Cu, 691 times for Sr, and 243 times for Ba. The increase in concentrations at other events where 24‐h samples were taken was present but not as pronounced and was lowest at football celebration events. [ABSTRACT FROM AUTHOR]

The performance of the Ca(OH) 2 –Al 2 O 3 –SiO 2 –H 2 O hydroceramic system (with and without Al 2 O 3) as a potential well cementing material was investigated from both macroscopic and microscopic perspectives. To simulate the harsh conditions typical of deep wells, marked by high temperature and pressure, the material was cured at 240 °C and 50 MPa. Several hydroceramic systems with varying compositions were designed and a retarder was used to optimize the thickening time of all systems. Finally, the optimized hydroceramic systems were cured for different periods ranging from 2 to 90 days to investigate their long-term stabilities. It is found that the raw materials with finer particle sizes and higher reactivity (such as silica fume and nano-activated alumina) could improve the performance of the hydroceramic system, evidenced by increased compressive strengths and decreased permeability. Changing the Ca/Si molar ratio within the range from 2:1 to 1:1 had little effect on the physical and mechanical properties of the hydroceramic system, despite significant variations in the composition of hydration products. The hydroceramic systems exhibited good stability over a curing period from 2 to 30 days, but strength retrogression phenomenon was observed during longer curing periods from 30 to 90 days. Microscopic evaluations revealed that the strength retrogression could be due to the formation of reyerite in high calcium systems, while it was the conversion of amorphous C–S–H to xonotlite that led to the strength retrogression in low calcium systems. [ABSTRACT FROM AUTHOR]

Background: With growing interest in hair health, researchers are exploring aspects beyond the surface qualities of hair, such as its porous inner structure. While previous studies have focused on the effects of treatments such as perming and hair dying on hair porosity, less emphasis has been paid to the effects of harmful environmental factors such as ultraviolet (UV) rays and particulate matter on the porous nature of hair. Aims: The aim of this study was to bridge this gap by investigating how UV rays and particulate matter affect hair porosity in different ways. Our study could help elucidate how these external factors influence hair health and shed light on previously unknown aspects of hair porosity. Methods: Hair tresses were bleached, cut into 1 cm‐long sections, and stained with methylene blue. The sections were then irradiated with UV light or exposed to particulate matter. Results: Bleached hair absorbed more methylene blue than normal hair. UV radiation‐induced hair porosity occurred at 3 h after irradiation and increased with time. Particulate matter alone did not affect the porosity of the damaged hair; however, in combination with UV irradiation, it substantially increased hair porosity. Conclusion: Environmental challenges such as a depleted ozone layer and increasing pollution may increase hair porosity, which can be prevented by maintaining healthy hair. [ABSTRACT FROM AUTHOR]

Although evidence has documented the associations of ambient air pollution with chronic respiratory diseases (CRDs) and lung function, the underlying metabolic mechanisms remain largely unclear. How does the metabolomic signature for air pollution relate to CRD risk, respiratory symptoms, and lung function? We retrieved 171,132 participants free of COPD and asthma at baseline from the UK Biobank, who had data on air pollution and metabolomics. Exposures to air pollutants (particulate matter with diameter ≤ 2.5 μm [PM 2.5 ], particulate matter with a diameter ≤ 10 μm, nitrogen oxide [NO X ], and NO 2) were assessed for 4 years before baseline considering residential address histories. We used 10-fold cross-validation elastic net regression to identify air pollution-associated metabolites. Multivariable Cox models were used to assess the associations between metabolomic signatures and CRD risk. Mediation and pathway analysis were conducted to explore the metabolic mechanism underlying the associations. During a median follow-up of 12.51 years, 8,951 and 5,980 incident COPD and asthma cases were recorded. In multivariable Cox regressions, air pollution was positively associated with CRD risk (eg, hazard ratio per interquartile range increment in PM 2.5 , 1.09; 95% CI, 1.06-1.13). We identified 103, 86, 85, and 90 metabolites in response to PM 2.5 , particulate matter with a diameter ≤ 10 μm, NO X , and NO 2 exposure, respectively. The metabolomic signatures showed significant associations with CRD risk (hazard ratio per SD increment in PM 2.5 metabolomic signature, 1.11; 95% CI, 1.09-1.14). Mediation analysis showed that peripheral inflammatory and erythrocyte-related markers mediated the effects of metabolomic signatures on CRD risk. We identified 14 and 12 perturbed metabolic pathways (energy metabolism and amino acid metabolism pathways, etc) for PM 2.5 and NO X metabolomic signatures. Our study identifies metabolomic signatures for air pollution exposure. The metabolomic signatures showed significant associations with CRD risk, and inflammatory- and erythrocyte-related markers partly mediated the metabolomic signatures-CRD links. [ABSTRACT FROM AUTHOR]

Associations between air pollution and the acute exacerbations (AEs) of COPD have been established primarily in time-series studies in which exposure and health data were at the aggregate level, limiting the identification of susceptible populations. Are air pollutants associated with the onset of AEs of COPD in China? Who is more susceptible to the effects of air pollutants? Data regarding AEs of COPD were obtained from the Acute Exacerbation of Chronic Obstructive Pulmonary Disease Registry (ACURE) study, and air pollution data were assigned to individuals based on their residential address. We adopted a time-stratified case-crossover study design combined with conditional logistic regression models to estimate the associations between six air pollutants and AEs of COPD. Stratified analyses were performed by individual characteristics, disease severity, COPD types, and the season of exacerbations. A total of 5,746 patients were included. At a 2-day lag, for each interquartile range increase in fine particulate matter and inhalable particulate matter concentrations, ORs for AEs of COPD were 1.054 (95% CI, 1.012-1.097) and 1.050 (95% CI, 1.009-1.092), respectively. The associations were more pronounced in participants who were younger than 65 years, who had experienced at least one severe AE of COPD in the past year, who had received a diagnosis of COPD between 20 and 50 years of age, and who had experienced AEs of COPD in the cool seasons. By contrast, significant associations for nitrogen dioxide, sulfur dioxide, and carbon monoxide lost significance when excluding patients collected before 2020 or with greater distance from the monitoring station, and no significant association was observed for ozone. This study provides robust evidence that short-term exposure to fine particulate matter and inhalable particulate matter was associated with higher odds of AEs of COPD onset. Individuals who are young, have severe COPD, or whose first diagnosis of COPD was made when they were between 20 and 50 years of age and experience an exacerbation during the cooler seasons may be particularly susceptible. ClinicalTrials.gov; No.: NCT2657525; URL: www.clinicaltrials.gov [ABSTRACT FROM AUTHOR]

A real-time air quality forecasting system was developed using the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) to provide support for flight planning activities during the NOAA Atmospheric Emissions and Reactions Observed from Megacities to Marine Areas (AEROMMA) and NASA Synergistic TEMPO Air Quality Science (STAQS) 2023 field campaigns. The forecasting system operated on two separate domains centered on Chicago, IL, and New York City, NY, and provided 72-hour predictions of atmospheric composition, aerosols, and clouds. This study evaluates the Chicago-centered forecasting system's 1-, 2-, and 3-day ozone (O3) forecast skill for Chiwaukee Prairie, WI, a rural area downwind of Chicago that often experiences high levels of O3 pollution. Comparisons to vertical O3 profiles collected by a Tropospheric Ozone Lidar Network (TOLNet) instrument revealed that forecast skill decreases as forecast lead time increases. When compared to surface measurements, the forecasting system tended to underestimate O3 concentrations on high O3 days and overestimate on low O3 days at Chiwaukee Prairie regardless of forecast lead time. Using July 25, 2023, as a case study, analyses show that the forecasts underestimated peak O3 levels at Chiwaukee Prairie during this regionwide bad air quality day. Wind speed and direction data indicates that this underestimation can partially be attributed to lake breeze simulation errors. Surface fine particulate matter (PM2.5) measurements, Geostationary Operational Environmental Satellite-16 (GOES-16) aerosol optical depth (AOD) data, and back trajectories from the NOAA Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model show that transported Canadian wildfire smoke impacted the Lake Michigan region on this day. Errors in the forecasted chemical composition and transport of the smoke plumes also contributed to underpredictions of O3 levels at Chiwaukee Prairie on July 25, 2023. The results of this work help identify improvements that can be made for future iterations of the WRF-Chem forecasting system. Implications: Air quality forecasting is an important tool that can be used to inform the public about upcoming high pollution days so that individuals may plan accordingly to limit their exposure to health-damaging air pollutants. Forecasting also helps scientists make decisions about where to make observations during air quality field campaigns. A variety of observational datasets were used to evaluate the accuracy of an air quality forecasting system that was developed for NOAA and NASA field campaigns that occurred in the summer of 2023. These evaluations inform areas of improvement for future development of this air quality forecasting system. [ABSTRACT FROM AUTHOR]

Flotation process is the most common beneficiation method of almost all types of minerals. The desirable result of the process is dependent on various factors. One of the most effective parameters in this regard is the particle size. Generally, acceptable results can be obtained by adjusting particle size in an optimum and specific range, and flotation of coarser or finer than this range is always intricate and problematic. Specifically, in the case of fine and ultra-fine particles, this complexity becomes more aggravated most importantly because of the massive specific area and the reduction of particle-bubble collision and attachment probabilities. There is a vast amount of literature on fine particles flotation using micro- and nanobubbles, intensified flotation machines, and different chemical reagents, however, the most promising procedure in this regard can be considered as the increment of particle sizes via agglomeration and flocculation techniques combined with flotation. This technique provides great opportunities for recovering fine and ultra-fine particles economically and increment of sustainable processing. However, there are some gaps and obscure points such as the exact mechanism of bubble-floc adsorption, interaction between flocs and reagents, pulp properties variations due to flocculation, and its effects on flotation behavior. This paper categorizes and describes diverse aspects of this combined novel technique in detail and provides a comprehensive source for readers to have a deeper insight into this intricate process. First of all, the physicochemical characteristics of the process have been described thoroughly from perspectives including the type and structure of applied chemicals, influential parameters, and involved adsorption mechanisms. It is followed by a detailed interpretation of different floc-flotation techniques as well as their cons and pros, effective parameters, and possible improvement and optimization approaches. Further, some similar techniques such as oil agglomeration, hydrophobic-hydrophilic Separation, and carrier flotation were described and compared with present technique of floc-flotation. Technological aspects of the process as well as an industrial case study of this technique were other areas which have been investigated in this paper and finally, scientific and technical gaps in this branch of flotation technology were extracted to open-up new horizon ahead of researchers active and/or interested in this field. [ABSTRACT FROM AUTHOR]

Epidemiologic studies have suggested a possible association between air pollution and chronic obstructive pulmonary disease (COPD), but it is controversial and difficult to draw causal inferences. Five methods were adopted to evaluate the causal relationship between air pollution and COPD in European and East Asian populations by using MR Analysis. A statistically significant causal relationship between PM2.5 and COPD was observed in the European population (OR: 2.34; 95% CI: 1.06–5.05; p = 0.033). Statistical significance remained after adjustment for confounding factors (adjusted OR: 2.28; 95% CI: 1.01–5.20; p = 0.048). In East Asian populations, PM2.5 absorbance, a proxy for black carbon, was statistically associated with COPD (OR: 1.41; 95% CI: 1.09–1.81; p = 0.007). We did not adjust for confounders in East Asian populations, as the association was independent of known confounders (e.g. smoking, respiratory tract infections, etc.). In conclusion, increased concentrations of PM2.5 and PM2.5 absorbance were associated with an increased risk of COPD. [ABSTRACT FROM AUTHOR]

Anaemia is an important global health issue with various factors responsible for its occurrence. Though nutritional deficiency is one of the main causes of the disease, evidence suggests a potential link between long-term exposure to ambient air pollution and an increased risk of developing anaemia. Our scoping review evaluates studies conducted across the world to examine possible associations between anaemia and ambient air pollution. Six databases were searched, 153 sources were identified, and 21 articles were included in the review. Apart from one article which showed no significant effect, studies reported positive associations between anaemia and air pollution. This was true for both indoor and outdoor air pollution, various types of particulate matter exposure, and across demographic groups. The review highlights the importance of recognizing exposure to air pollution as a potential risk factor for anaemia and emphasizes the imperative for focused interventions and policy measures to mitigate air pollution. [ABSTRACT FROM AUTHOR]

Satellite-based exposure of fine particulate matters has been seldom used as a predictor of mortality. PM2.5 was predicted using Aerosol Optical Depths (AOD) through a two-stage regression model. The predicted PM2.5 was corrected for the bias using two approaches. We estimated the impact by two different scenarios of PM2.5 in the model. We statistically found different distributions of the predicted PM2.5 over the region. Compared to the reference value (5 µg/m3), 90th and 95th percentiles had significant adverse effect on total mortality (RR 90th percentile:1.45; CI 95%: 1.08–1.95 and RR 95th percentile:1.53; CI 95%: 1.11–2.1). Nearly 1050 deaths were attributed to any range of the air pollution (unhealthy range), of which more than half were attributed to high concentration range. Given the adverse effect of extreme values compared to the both scenarios, more efforts are suggested to define local-specific reference values and preventive strategies. [ABSTRACT FROM AUTHOR]

The Permian Basin is the largest petroleum producing region in the United States. Few studies have investigated impact the Petroleum Industry had on the air quality of the Permian Basin. Industry operations in the Basin has two primary impacts on air quality, (a) it significantly contributes carbon dioxide (CO2) and methane (CH4) to the atmosphere during extraction, transport and use of fossil fuels, (b) industry operations influence public health especially when populations are in proximity to all categories of oil and gas facilities. The advent of Covid-19 in late 2019 and a severe drought that began prior to 2019 in West Texas have created unusual circumstances regarding air quality and public health in the Permian Basin. This study has monitored airborne pollen, spores, fungal spores, and other organically derived particles, and inorganic particulate matter (1, 2.5, 10-micron particulate matter (PM) and total suspended particles (TSP)), volatile organic compounds (VOCs), and sulfur dioxide (SO2). The pandemic caused a historic reduction in oil and gas production slowing operations in the Permian Basin to near zero during the study period, reducing environmental effects on air quality and concomitantly an increase in flaring of natural gas. Although there were increases in the release of VOCs fixed base monitors detected no notable increase. However, an increase in the concentration of airborne pollutants (VOCs and SO2) shows a close correlation with proximity to oil and gas facilities and the intensity of industry operations. This phenomenon is attributed to the highly local nature of flaring and CH4 plume emissions from leaking oil and gas facilities. Air quality improved in the Permian Basin due to reduction in production activity because of the Covid-19 pandemic, and the reduction of particulate matter due to the ongoing drought during the study period. [ABSTRACT FROM AUTHOR]

• 12 studies have examined links between air pollutants and cortical thickness. • PM 2.5 was the most studied pollutant and impactful on decreasing cortical thickness. • Some studies reported both regional increasing and decreasing cortical thickness. • Further research is needed examining life course pollution and cortical thickness. Increasing research has focused on the impact of air pollution on brain health. As the prevalence of air pollution is increasing alongside other environmental harms, the importance of studying the effects of these changes on human health has become more significant. Additionally, gaining insight into how air pollution exposure, measured at different points in the lifespan, can affect brain structure is critical, as this could be a precursor to cognitive decline later in life. The purpose of this review was to synthesize the literature on the association between air pollutant exposure and cortical thickness, a structural change with known associations with later cognition and neurodegenerative disease. After screening, twelve studies were included in this systematic review. Across a majority of studies, results suggest significant associations between increasing air pollution exposure and decreases in cortical thickness, primarily in areas such as prefrontal cortex, precuneus, and temporal regions of the brain. These results did differ somewhat between age groups and different air pollutants, with the most prominent results being found with exposure to PM 2.5 , the smallest particulate matter size included in the review. In the future, it is important to continue studying cortical thickness as it is essential to brain functioning and can be influential in disease progression. Furthermore, conducting more longitudinal studies in which air pollution is measured as a cumulation throughout the lifespan would help elucidate when exposure is most impactful and when brain structural changes become observable. [ABSTRACT FROM AUTHOR]

This study aims to assess ecological risks from heavy metal atmospheric deposition in the Indus River at Kotri Barrage, Sindh, Pakistan. Monitoring occurred at four locations, yielding 40 air samples analyzed for heavy metals via Triple Quadrupole Inductively Coupled Plasma Mass Spectrometry (TQ-ICP-MS). Pollution indicators, including Contaminant Factor (CF), Degree of Contamination (CD), Geo-accumulation Index (Igeo), Enrichment Factor (EF), Pollution Load Index (PLI), Potential Ecological Risk Index (PERI), and Nemerow Integrated Pollution Index (NIPI), quantified contaminant levels. Air monitoring revealed PM2.5 concentrations exceeding regulatory guidelines at all four sites. Heavy metal mean concentrations ranked as follows: Fe > Cr > Pb > Mn > As > Cu > Ni > Cd > Mo > Co, and deposition fluxes followed this order: Fe > Pb > Cr > Mn > As > Cu > Ni > Cd > Mo > Co. Pollution indices indicated moderate to extreme pollution for Fe, Cr, Cd at all sites, and Pb at site D. Emissions from a nearby coal-fired power plant and vehicular sources were identified as primary contributors to high heavy metal deposition. The Ecological Risk Index ranged from 150 to 600, signifying substantial ecological risk linked to Cd. These findings offer crucial insights for governmental agencies and policymakers to address pollution issues arising from heavy metal atmospheric deposition in the Indus River near Kotri Barrage. [ABSTRACT FROM AUTHOR]

Foliar fungi on urban trees are important for tree health, biodiversity and ecosystem functioning. Yet, we lack insights into how urbanization influences foliar fungal communities. We created detailed maps of Stockholm region's climate and air quality and characterized foliar fungi from mature oaks (Quercus robur) across climatic, air quality and local habitat gradients. Fungal richness was higher in locations with high growing season relative humidity, and fungal community composition was structured by growing season maximum temperature, NO2 concentration and leaf litter cover. The relative abundance of mycoparasites and endophytes increased with temperature. The relative abundance of pathogens was lowest with high concentrations of NO2 and particulate matter (PM2.5), while saprotrophs increased with leaf litter cover. Our findings show that urbanization influences foliar fungi, providing insights for developing management guidelines to promote tree health, prevent disease outbreaks and maintain biodiversity within urban landscapes. [ABSTRACT FROM AUTHOR]

The application of ultrafine bubbles a.k.a. nano-bubbles (NBs) in upgrading the flotation recovery of fine particles has been extensively investigated from various perspectives over the last two decades. However, their rheological aspect has not been studied yet, which is presented for the first time in this paper. To this end, the current study addresses the effect of six crucial variables including solid content (5%, 15%, and 25% (w/w)), presence and absence of NBs, inner diameter of a Venturi tube (1.5 and 2.2 mm), pH of pulp (4.5–11) and frother dosage (3, 13, and 33 mg/L) on the variation of rheological parameters i.e. shear stress, shear tension, and viscosity. Ultrafine bubbles were generated in a conditioning tank through the hydrodynamic cavitation mechanism using a fatty-acid-based frother (Flo-Y-S), while the rheological responses were continuously monitored and measured by a rheometer and parallel plate spindle (for pulp) and a double gap spindle (for NBs). Flotation tests were conducted on a high-grade phosphate ore (d80 = 37 µm) using a mechanically agitated Denver®-type (D12) flotation cell. The experimental results revealed that fluid behavior without NBs using 13 mg/L frother was in the range of shear rates less than 1 s−1 non-Newtonian and close to the shear thinning state, while it became completely Newtonian in the range of 1 to 1500 s−1. However, the presence of NBs at the same frother content changed this tendency to non-Newtonian and Newtonian fluids at shear rates of <30 s−1 and >30 s−1, respectively. It was also found that either in acidic (5.5) or strong alkaline (11) domains, the pulp viscosity trends were almost close to each other and varied from 0.002−10 to 0.002−4 Pa.s, respectively. On the other hand, on the same trend, the amount was lowered to three times in the neutral range (7.5) and weak alkalinities (9). Diminishing the inner diameter of the Venturi tube from 2.2 mm to 1.5 mm led to an increment of shear stress and viscosity about twice at the shear rates <100 s−1. The results of evaluating frother dosage showed that an increase in the amount of frother dosage, which reduced bubble dimensions, exceeded the viscosity and the amount of shear stress. Finally, we concluded that the rheological properties significantly impacted the selective separation of NB-assisted flotation processes and need further investigations in the future. [ABSTRACT FROM AUTHOR]

Information on microorganisms in indoor air of various institutional and commercial buildings has significant value in a public health management perspective. However, there is a lack of prior research comparing indoor airborne microbiota across different categories of those buildings. We characterized indoor airborne bacteria in 10 buildings (two for each of five categories: train station, parking garage, mart, public library, and daycare center) during summer and winter. The 16S rRNA gene in the bacterial gDNA extracted from samples was quantified using quantitative real-time polymerase chain reaction and sequenced with the Illumina MiSeq™ platform for characterizing community composition. We collected information on temperature, relative humidity, CO2 concentration, and particulate matter (PM) concentrations by particle size (<1 µm, 1–2.5 µm, 2.5–10 µm) indoors. We performed a multivariate regression analysis to identify factors influencing bacterial quantity and Permutational Multivariate Analysis of Variance (PERMANOVA) to determine factors affecting cluster dissimilarity. We found that bacterial concentration was significantly (p-values < 0.05) associated with season and CO2 concentration. The PERMANOVA analyses showed the significant (p-values < 0.05) associations of bacterial cluster dissimilarity with season, building category, and CO2. Our study indicated that the season, and CO2 concentrations may be important factors associated with the indoor airborne bacterial concentration and composition. Building category and usage appeared to significantly influence the bacterial community composition but not the concentration. Our study may provide basic data on bacterial community composition and their concentration that are needed for properly managing microbial exposures in occupants or customers of the studied institutional and commercial buildings. Copyright © 2024 American Association for Aerosol Research [ABSTRACT FROM AUTHOR]

Brake wear particles (BWPs) are a major particulate matter (PM) emission of vehicles and they will be regulated under EURO-7 emission standards. To comply with EURO-7, some BWP emission reduction devices have been recently developed. However, most of the studies tested the devices in laboratory conditions, not actual vehicle conditions. In this study, a dust collector composed of a suction device and an electrostatic precipitator (EP) was developed to reduce BWP emission and it was tested on laboratory and actual vehicle. The collection efficiency (CE) of EP was studied under laboratory conditions using a brake dynamometer. More than 95% of BWPs were removed when the EP exhibited a corona charge imparted using a carbon brush. CE would not be changed in laboratory and actual vehicle conditions. The suction efficiency (SE) of the suction device was tested in laboratory and actual vehicle conditions. In the laboratory, the SE decreased from a maximum of 88–62% as the disk rotational speed increased. Although it was possible to maintain the EP CE above 95%, the SE was approximately 70%; the overall BWP reduction efficiency remained in the 60% range. SE had a dominant effect on total reduction efficiency. For actual vehicle testing, the reduction efficiency was 75%, higher than the value measured in laboratory conditions. Therefore, BWP emission reduction device must be tested in actual vehicles to estimate their efficiency in the real-world. Copyright © 2024 American Association for Aerosol Research [ABSTRACT FROM AUTHOR]

Researchers have explored the utilization of nanoparticles to improve the properties of soils for various geotechnical construction applications. However, the potential of nanoparticles and their mechanisms of action in enhancing the behavior of industrial byproduct pozzolanic materials has not been properly examined. Hence, in the present study, we aimed to investigate and optimize montmorillonite nanoclay (m-NC) content to improve the engineering properties (unconfined compressive strength, compressibility and permeability) of fly ash with and without lime treatment. In addition, we examined the leaching potential of metal ions through m-NC amended with untreated and lime-treated fly ash by performing leachate column and inductively coupled plasma mass spectrometry (ICP-MS) tests. The mechanisms of change in the engineering properties of lime-treated fly ash with m-NC were uncovered through several microlevel investigations. The results revealed that the strength of untreated and lime-treated fly ash was enhanced significantly with the addition of m-NC. Furthermore, the addition of m-NC to fly ash led to increased compressibility but in same time, it reduces for lime-treated fly ash. However, the permeability of untreated and lime-treated fly ash decreased with the addition of m-NC. The leaching potential of metal ions decreased significantly with the addition m-NC to fly ash. Microlevel investigations confirmed the plate-like fine particles having higher specific surface area of m-NC, improvement in gradation with filling of voids and acceleration in pozzolanic reactivity and thereby formation of silicate and aluminate hydrated cementitious compounds are the key factors in controlling the behavior of lime-treated fly ash with m-NC content. [ABSTRACT FROM AUTHOR]

Wetting–drying cycles have a significant impact on the gas diffusion coefficient (Dp) and gas permeability (ka) of unsaturated soils. The soil volume change during wetting–drying cycles limits the application of the traditional rigid-wall device for measuring ka and Dp , due to the gas preferential flow along the interface between soil and the rigid-wall container. Although flexible-wall devices for measuring ka are available, no such device exists for measuring Dp. Thus, the effects of wetting–drying cycles on Dp remain unclear, particularly for fine-grained soil. The present study developed a flexible-wall device to investigate the effects of a wetting–drying cycle on the Dp and ka of unsaturated soils. Both the flexible- and rigid-wall devices were adopted to measure ka and Dp of three soil types, including fine sand, silt and kaolin. The rigid-wall device could overestimate ka by up to approximately one order of magnitude, whereas it overestimated Dp by approximately 2–3 times. Regardless of ka and Dp , the difference in measurements between the rigid- and flexible-wall devices became more significant at a lower water content and along the drying path because of the gas preferential flow caused by soil shrinkage in the rigid-wall device. Accordingly, the kaolin exhibited the largest difference in ka and Dp as measured by the flexible- and rigid-wall devices because it had the largest clay minerals and the finest particle size, resulting in the largest volume shrinkage. The ka and Dp measured by the flexible-wall device along the drying path were generally larger than those along the wetting path, probably because of entrapped gas in the soil caused by water spray during wetting. [ABSTRACT FROM AUTHOR]

Fine particulate matter is challenging to capture due to its minuscule size, which affects its chargeability. The agglomeration method has been proven to be the most effective pretreatment technology for enhancing the removal of fine particles. This study proposes a novel dust-removal system that integrates turbulence-induced agglomeration into the wet electrostatic precipitator. The results showed that the removal efficiency of fine particles with a negative corona voltage was significantly higher, and removal efficiencies for particles smaller than 10.0 μm exceeded 90%. Furthermore, fine particles carried a larger charge when subjected to negative corona discharge, resulting in more-effective dust retention. The turbulence effect facilitates the removal of fine particles by promoting their agglomeration in turbulent conditions. The removal efficiency can increase significantly with turbulence, and this enhancement effect is more pronounced at higher flow rates. This study provides insight into the comprehensive removal of multiple pollutants from industrial flue gases. [ABSTRACT FROM AUTHOR]

Evaluating the cyclic strength development using energy-based methods is a novel concept in studying the dynamic properties of sand–clay mixtures under cyclic loading. In this study, a series of undrained cyclic triaxial tests were conducted on sand–clay mixtures, and the performance of different fine-grain contents on the dynamic properties and the energy dissipation of sand–clay mixtures was investigated based on the energy-based methods. The results demonstrated a gradual increase in the cyclic strain amplitude and the residual axial strain with increasing fines content (FC) under cyclic loading with a controlled cyclic stress ratio; in contrast, the accumulation of pore-water pressure slowed down. An initial decrease in the cyclic strength of the mixtures was observed with an increase in their fines contents; however, further increasing the FC enlarged the cyclic strength of the sand–clay mixtures. This transition was observed when the threshold fines content reached about 30%. The viscous energy dissipation ratio (VEDR), which is a nondimensional energy ratio based on the relationship between cyclic stress and strain and reflects the characteristics of dynamic properties, was utilized to compare three critical phase transition points, namely, VEDRvalley, VEDRpeak, and VEDR5%strain, in the energy dissipation of the sand–clay mixtures. Based on the VEDR results, the cyclic strength development indexes were established. Furthermore, low-vacuum environmental scanning electron microscopy revealed that as the FC increased, the particle composition of the sand–clay mixtures transitioned from predominantly coarse-grained to fine-grained, resulting in a change in the cyclic behavior of the mixtures from sandlike to claylike. The cyclic strength development indices provided further insights into and quantified the effect of fines contents of the sand–clay mixtures on their cyclic strength development process. [ABSTRACT FROM AUTHOR]