Small Particulate Matter Research Articles

A Critical Review on the Experimental Setups Used to Assess the Efficiency of Respirators Against Ambient Particulate Matter

Abstract: Fine particulate matter (PM2.5) poses significant health risks, prompting public health organizations to recommend the use of respirators and facemasks (RFMs) to mitigate exposure. Consequently, interest in their usage has increased, leading to several studies assessing the efficiency of these personal-level interventions against various fractions of ambient particulate matter (PM). We conducted a comprehensive literature search across PubMed, Web of Science, and Scopus to identify relevant studies and address the following objectives: (1) explore the efficiency of RFMs in reducing ambient PM; (2) discuss discrepancies in efficiencies reported; (3) critique the experimental setups used to evaluate the efficiency of RFMs; and (4) propose recommendations for future research. Five relevant studies we reviewed reported significantly lower RFM effectiveness against ambient PM, with a size-dependent efficiency that decreases for smaller PM fractions. Variations in the reported efficiencies were primarily attributed to design-related factors, resulting in poor facial fit. Therefore, it is crucial to consider standardizing and properly designing these products. These studies overlooked essential factors, such as using dummy heads with flexible textures that mimic human skin. The use of rigid-textured dummy heads, as seen in previous studies, may fail to accurately represent real-world conditions. We recommend researchers take into account diverse facial profiles in their experiments. Moreover, it is essential to consider facial characteristics in the design of RFMs. We believe the evidence supports the increasing need for the adoption of appropriate guidelines and regulations to govern RFM suppliers at both national and international levels.

Anti-Inflammatory Effect of Ethanol Extract from Hibiscus cannabinus L. Flower in Diesel Particulate Matter-Stimulated HaCaT Cells.

Diesel Particulate Matter (DPM) is a very small particulate matter originating from cities, factories, and the use of fossil fuels in diesel vehicles. When DPM permeates the skin, it causes inflammation, leading to severe atopic dermatitis. Hibiscus cannabinus L. (Kenaf) seeds and leaves possess various beneficial properties, including anti-coagulation, antioxidant, and anti-inflammation effects. In this study, we investigated the anti-inflammatory effects of an ethanol extract of Hibiscus cannabinus L. flower (HCFE) in HaCaT cells stimulated with 100 μg/mL of DPM. The anthocyanin content of HCFE was analyzed, and its antioxidant capacity was investigated using the DPPH assay. After inducing inflammation with 100 ug/mL of DPM, the cytotoxicity of HCFE 25, 50, and 100 ug/mL was measured, and the inhibitory effect of HCFE on inflammatory mediators was evaluated. Anthocyanin and myricetin-3-O-glucoside were present in HCFE and showed high antioxidant capacity. In addition, HCFE decreased the mRNA expression of inflammatory cytokines and chemokines such as IL-1β, IL-4, IL-6, IL-8, IL-13, and MCP-1, and significantly reduced the gene expression of CXCL10, CCL5, CCL17, and CCL22, which are known to increase in atopic dermatitis lesions. Furthermore, HCFE reduced intracellular reactive oxygen species (ROS) production, and down-regulated the activation of NF-κB, MAPKs. Inhibition of the NLRP-3 inflammasome was observed in DPM-stimulated HaCaT cells. In addition, the restoration of filaggrin and involucrin, skin barrier proteins destroyed by DPM exposure, was confirmed. These data suggest that HCFE could be used to prevent and improve skin inflammation and atopic dermatitis through the regulation of inflammatory mediators and the inhibition of skin water loss.

Estimation methods for the variance of Birnbaum-Saunders distribution containing zero values with application to wind speed data in Thailand.

Thailand is currently grappling with a severe problem of air pollution, especially from small particulate matter (PM), which poses considerable threats to public health. The speed of the wind is pivotal in spreading these harmful particles across the atmosphere. Given the inherently unpredictable wind speed behavior, our focus lies in establishing the confidence interval (CI) for the variance of wind speed data. To achieve this, we will employ the delta-Birnbaum-Saunders (delta-BirSau) distribution. This statistical model allows for analyzing wind speed data and offers valuable insights into its variability and potential implications for air quality. The intervals are derived from ten different methods: generalized confidence interval (GCI), bootstrap confidence interval (BCI), generalized fiducial confidence interval (GFCI), and normal approximation (NA). Specifically, we apply GCI, BCI, and GFCI while considering the estimation of the proportion of zeros using the variance stabilized transformation (VST), Wilson, and Hannig methods. To evaluate the performance of these methods, we conduct a simulation study using Monte Carlo simulations in the R statistical software. The study assesses the coverage probabilities and average widths of the proposed confidence intervals. The simulation results reveal that GFCI based on the Wilson method is optimal for small sample sizes, GFCI based on the Hannig method excels for medium sample sizes, and GFCI based on the VST method stands out for large sample sizes. To further validate the practical application of these methods, we employ daily wind speed data from an industrial area in Prachin Buri and Rayong provinces, Thailand.

Assessing the particulate matter emission reduction characteristics of small turbofan engine fueled with 100 % HEFA sustainable aviation fuel

With the continuous increase in global air transportation, the impact of ultrafine particulate matter (PM) emissions from aviation on human health and environmental pollution is becoming increasingly severe. In addition to carbon reduction throughout the lifecycle, Sustainable Aviation Fuels (SAF) also represent a significant pathway for reducing PM emissions. However, due to issues such as airworthiness safety and adaptability, existing research has mostly focused on the emission performance of SAF when blended with traditional fuels at <50 %, leaving the emission characteristics of higher blending ratios to be explored. In this study, using measurement methods recommended by the International Civil Aviation Organization (ICAO), the PM emission reduction characteristics of small turbofan engines fueled with 100 % Hydroprocessed Esters and Fatty Acids (HEFA)-SAF were experimentally evaluated and compared with traditional fuels RP-3 and Diesel, while avoiding the interference of lubricant blending combustion. The results showed that the peak number concentration of particle size distribution (PSD), PM total number, as well as the number and mass concentration of non-volatile particulate matter (nvPM) decreased initially and then increased with rising thrust conditions. HEFA-SAF exhibits PSD with smaller diameters, and the Geometric Mean Diameter (GMD) ranges from 7.7 nm to 20.3 nm under all conditions. Both volatile particulates (vPM) and nvPM from HEFA-SAF are significantly reduced, with nvPM number emission index (EIn) being 92 % and 71 % lower than Diesel and RP-3, respectively. The nvPM mass emission index (EIm) also shows reductions of 96 % and 89 % compared to Diesel and RP-3. Microscopic characterization also indicated that using HEFA-SAF emitted fewer and smaller PMs. This study establishes a foundation for evaluating the effectiveness of 100 % SAF in reducing PM emissions within the aviation sector, and contributes to the airworthiness regulations development related to the use of SAF in a variety of application environments, alongside enhancing environmental protection measures.

Gene-environment interactions between clonal hematopoiesis of indeterminate potential and air pollution in non-small cell lung cancer among non-smokers.

10514 Background: Small particulate matter air pollution (≤ 2.5µm diameter; PM2.5) is a recognized driver of non-small cell lung cancer (NSCLC) among non-smokers. PM2.5 recruits pro-inflammatory macrophages to the lungs, which facilitate the clonal expansion of mutated epithelial cells and eventual transformation to NSCLC. Clonal hematopoiesis of indeterminate potential (CHIP) is a common age-related condition caused by the acquisition of somatic mutations in hematopoietic stem cells. CHIP and its accompanying pro-inflammatory phenotype have been linked with various age-related diseases, including incident NSCLC; however, the mechanisms underlying this relationship are unknown. In this study, we aimed to explore the interaction between CHIP and exposure to PM2.5 in the development of incident NSCLC. Methods: This study was conducted using data from participants in the UK Biobank (n = 451,095). CHIP status was determined from peripheral blood whole exome sequencing data, and defined as the presence of a somatic driver mutation in the blood at variant allele frequency (VAF) ≥2% (PMID: 36652671). Incident NSCLC was determined from UK cancer registry data, and PM2.5 exposure was determined based on ambient regional measures from 2010. Cox proportional hazard models were used to evaluate associations between CHIP, PM2.5, and NSCLC. Proteomics data was measured using OLINK proteomics in a subset of UK Biobank participants (n = 44,625). Results: CHIP was prevalent in 3.4% of UK Biobank participants (n = 15,633; never smokers: 3.0%, n = 6,916/227,133). There were 1983 incident cases of NSCLC (never smokers: n = 307). CHIP status was associated with incident NSCLC when adjusting for smoking status (HR = 1.73, 95% CI: 1.48–2.02) and analyzing exclusively non-smokers (HR = 2.01, 95% CI: 1.34-3.00). PM2.5 levels were not associated with NSCLC in non-smokers (HR = 1.00, 95% CI: 0.89–1.12 per µg/m3 increase in PM2.5); however, there was a significant interaction between PM2.5 and CHIP (HR = 1.46, 95% CI: 1.02–2.11, pint = 0.04), suggesting that it is the interplay between the two that drives incident NSCLC risk. We found no association between PM2.5 levels and increased CHIP prevalence or CHIP VAF. PM2.5 and CHIP were also found to interact to increase systemic inflammatory markers C-reactive peptide (pint = 0.01) and IL-6 (pint = 0.002). Conclusions: PM2.5 and CHIP act as a novel gene x environment interaction pair that play a key role in NSCLC etiology among non-smokers. Rather than acting in isolation to increase risk of NSCLC, PM2.5 intensifies the relationship between CHIP and NSCLC, presumably by exacerbating systemic inflammation and the hyper-inflammatory lung microenvironment. With PM2.5 levels in the UK among the lowest in the world, we posit that the CHIP x PM2.5 interaction contributes substantially to the global burden of NSCLC in non-smokers.

Medium-term exposure to size-fractioned particulate matter and asthma exacerbations in China: A longitudinal study of asthmatics with poor medication adherence

BackgroundStudies have shown that short- and long-term exposure to particulate matter (PM) can increase the risk of asthma morbidity and mortality. However, the effect of medium-term exposure remains unknown. We aim to examine the effect of medium-term exposure to size-fractioned PM on asthma exacerbations among asthmatics with poor medication adherence. MethodsWe conducted a longitudinal study in China based on the National Mobile Asthma Management System Project that specifically and routinely followed asthma exacerbations in asthmatics with poor medication adherence from April 2017 to May 2019. High-resolution satellite remote-sensing data were used to estimate each participant's medium-term exposure (on average 90 days) to size-fractioned PM (PM1, PM2.5, and PM10) based on the residential address and the date of the follow-up when asthma exacerbations (e.g., hospitalizations and emergency room visits) occurred or the end of the follow-up. The Cox proportional hazards model was employed to examine the hazard ratio of asthma exacerbations associated with each PM after controlling for sex, age, BMI, education level, geographic region, and temperature. ResultsModelling results revealed nonlinear exposure-response associations of asthma exacerbations with medium-term exposure to PM1, PM2.5, and PM10. Specifically, for emergency room visits, we found an increased hazard ratio for PM1 above 22.8 µg/m3 (1.060, 95 % CI: 1.025–1.096, per 1 µg/m3 increase), PM2.5 above 38.2 µg/m3 (1.032, 95 % CI: 1.010–1.054), and PM10 above 78.6 µg/m3 (1.019, 95 % CI: 1.006–1.032). For hospitalizations, we also found an increased hazard ratio for PM1 above 20.3 µg/m3 (1.055, 95 % CI: 1.001–1.111) and PM2.5 above 39.2 µg/m3 (1.038, 95 % CI: 1.003–1.074). Furthermore, the effects of PM were greater for a longer exposure window (90–180 days) and among participants with a high BMI. ConclusionThis study suggests that medium-term exposure to PM is associated with an increased risk of asthma exacerbations in asthmatics with poor medication adherence, with a higher risk from smaller PM.

A stronger association of mental disorders with smaller particulate matter and a modifying effect of air temperature

Mental disorders (MDs) can be triggered by adverse weather conditions and particulate matter (PM) such as PM2.5 and PM10 (aerodynamic diameter ≤2.5 μm and ≤10 μm). However, there is a dearth of evidence on the role of smaller PM (e.g. PM1, aerodynamic diameter ≤1 μm) and the potential modifying effects of weather conditions. We aimed to collect daily data on emergency department visits and hospitalisations for schizophrenia-, mood-, and stress-related disorders in a densely populated Chinese city (Hefei) between 2016 and 2019. A time-stratified case-crossover analysis was used to examine the short-term association of MDs with PM1, PM2.5, and PM10. The potential modifying effects of air temperature conditions (cold and warm days) were also explored. The three size-fractioned PMs were all associated with an increased risk of MDs; however, the association differed between emergency department visit and hospitalisation. Specifically, PM1 was primarily associated with an increased risk of emergency department visit, whereas PM2.5 was primarily associated with an increased risk of hospitalisation, and PM10 was associated with an increased risk of both emergency department visit and hospitalisation. The PM-MD association appeared to be greatest (although not significant) for PM1 (odds ratio range: 1.014–1.055), followed by PM2.5 (odds ratio range: 1.001–1.009) and PM10 (odds ratio range: 1.001–1.006). Furthermore, the PM-MD association was observed on cold days; notably, the association between PM and schizophrenia-related disorders was significant on both cold and warm days. Our results suggest that the smaller the PM, the greater the risk of MDs, and that the PM-MD association could be determined by air temperature conditions.

Gelatin-reinforced cellulose nanofiber composite cryogels for effective separation of small particulate matter in air

Herein, novel composite aerosol filters solely comprising renewable materials were designed using gelatin as a reinforcement agent and aqueous tert-butyl alcohol (TBA) as a dispersing medium for the cellulose nanofiber skeleton. The prepared composite cryogels exhibited distinct spider-web-like crosslinked structures and nanoporous architectures with porosity exceeding 98.8 % and density of less than 0.018 g/cm3. These composite filters exhibited high filtration efficiency and a robust and flexible mechanical structure due to gelatin reinforcement; furthermore, their quality factor exceeded the target threshold of 0.01 Pa−1 for 300 nm particle size. The filtration performance and mechanical properties of the composite filters could be tailored by adjusting the cellulose nanofiber (CNF), gelatin, and TBA contents, enabling the preparation of cryogels with a firm and strong structure. This study introduces ultraporous solids based on nanocellulose (NC) cryogels, which are promising, novel, and green materials for the production of advanced high-performance filter media for aerosol separation. Furthermore, the aforementioned approach is promising for the preparation of mechanically robust nanoporous biomaterials suitable for diverse applications such as heat and thermal insulation.

Monitoring of farmland dust during tillage and sowing operations and comparative analysis of cultivation modes in the suburban areas of Beijing

Agricultural machinery's tillage and sowing processes can generate much farmland dust, adversely affecting the surrounding environment. Clarifying the dust emissions from various agricultural machinery operations and selecting a reasonable cultivation mode is significant for reducing dust in the atmosphere and protecting the environment. However, a systematic exploration of the agricultural dust generated during agricultural machinery operations is needed. Here, we designed a dust monitoring system to monitor farmland dust (PM2.5, PM10, and TSP) and environmental parameters at different points. The system is applied to monitor the dust emission concentration caused by agricultural machinery. We found the concentration of PM2.5, PM10, and TSP from straw returning operations to be 2.06, 3.16, and 2.84 times higher than that of ploughing operations. The increase in cultivation speed will lead to an increase in dust concentration. In straw returning operations, compared with low-speed, the increase in PM2.5, PM10, and TSP concentration during medium-speed cultivation is 21.6%, 12.5%, and 16.8%, whereas high-speed cultivation is 68.2%, 38.9%, and 35.7%, respectively. Moreover, conservation tillage modes can significantly suppress dust emissions. We found that conservation tillage produced the lowest concentrations of PM2.5, PM10, and TSP during the tillage and sowing stages, which were 64.7%, 73.1%, and 72.1%, compared to traditional tillage. As the amount of straw coverage increases, the dust concentration decreases. The average PM2.5, PM10, and TSP concentration increment of NTS with LSMQ increased by 307.8%, 344.8%, and 346.8%. Our results demonstrate that adopting a conservation tillage and sowing model and increasing straw coverage can reduce dust emissions. The research results have specific guiding significance for reducing dust emissions during the spring and autumn cultivation. We anticipate evaluating further the contribution of small particulate matter generated during agricultural machinery operations to air pollution, and our research will provide a basis for future work.

Holographic Air‐Quality Monitor (HAM)

We introduce the holographic air‐quality monitor (HAM) system, uniquely tailored for monitoring large particulate matter (PM) over 10 μm in diameter—particles critical for disease transmission and public health but overlooked by most commercial PM sensors. The HAM system utilizes a lensless digital inline holography (DIH) sensor combined with a deep learning model, enabling real‐time detection of PMs with greater than 97% true positive rate at less than 0.6% false positive rate and analysis of PMs by size and morphology at a sampling rate of 26 L/min for a wide range of particle concentrations up to 4000 particles/L. Such throughput not only significantly outperforms traditional imaging‐based sensors but also rivals some lower‐fidelity, nonimaging sensors. Additionally, the HAM system is equipped with additional sensors for smaller PMs and various air quality conditions, ensuring a comprehensive assessment of indoor air quality. The performance of the DIH sensor within the HAM system was evaluated through comparison with brightfield microscopy, showing high concordance in size and morphology measurements. The efficacy of the DIH sensor was also demonstrated in two 2‐h experiments under different environments simulating practical conditions, with one involving distinct PM‐generating events. These tests highlighted the HAM system’s advanced capability to differentiate PM events from background noise and its exceptional sensitivity to irregular, large‐sized PMs of low concentration.

Effect of Reaction Temperature on the Degradation and Oxidation Behavior of Particulate Matter by Nonthermal Plasma

Diesel particulate matter (PM), especially small particle size PM, has been highlighted as a hazard to the environment and people. Nonthermal plasma (NTP) has shown significant low temperature (<200°C) advantage for PM degradation. In this paper, we conducted online PM degradation experiments at different reaction temperatures with a self-built NTP injection system to investigate the changes of PM particle size distribution, micro-nano structure, graphitization degree and oxidation characteristics of elemental carbon (EC) before and after NTP action. The maximum removal rate increased from 90 ℃ (25% load) to 130 ℃ (100% load) with the increase of the load, and there was a “trade-off” effect between PM decomposition and NTP pyrolysis. The average microcrystalline length, microcrystalline spacing and microcrystalline curvature of PM particles showed an overall trend of decreasing and then increasing with the increase of temperature. When the reaction temperature was 130 ℃ (75% load), the microcrystalline structure parameters of the carbon particles showed extreme values, and the newly exposed “shells” were rearranged under the action of van der Waals force, and the graphitization of PM increased and the overall oxidation activity was weakened. The reaction between NTP and carbon particles goes through the process of surface oxidation, simultaneous oxidation of surface and interior, and the fragmentation of carbon particles to complete disappearance.

Improvements in the determination of attogram-sized 231Pa in dissolved and particulate fractions of seawater via multi-collector inductively coupled plasma mass spectrometry

A technique is developed to quantify the ultra-trace 231Pa (35–3904 ag) concentration in seawater using multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). The method is a modification of the process developed by Shen et al. (Anal Chem 75(5):1075–1079, 2003. https://doi.org/10.1021/ac026247r) and extends it to the application of very low levels of actinides, and the 35 ag 231Pa can be measured with a precision of 15%. The total process blank for the water column was 0.02 ag/g, while the values of the large and small particles were ~ 30 ag/g. The ionization efficiency (ions generated/atom loaded) varies from 0.7 to 2.4%. The measurement time is 2–5 min. The amount of 231Pa needed to produce 231Pa data with an uncertainty of ± 0.8–15% is 35–3904 ag (~ 0.9 × 105 to 10 × 106 atoms). Replicate measurements of known standards and seawater samples demonstrate that the analytical precision approximates that expected from counting statistics, and that based on detection limits of 52 ag, 55 ag, and 28 ag, protactinium can be detected in a minimum seawater sample size of ~ 2.6 L for small suspended particulate matter (> 0.8 μm and < 51 μm), ~ 3.0 L for large suspended particulate matter (> 51 μm), and ~ 56 mL for filtered (< 0.45 μm) seawater. The concentration of 231Pa (several attograms per liter) can be determined with an uncertainty of ± 2–8% (2σ) for suspended particulate matter filtered from ~ 60 L of seawater. For the dissolved fraction, ~ 1 L of seawater yields 231Pa measurements with a precision of 0.8–10%. The sample size requirements are several orders of magnitude less than traditional decay-counting techniques, and the precision is better than that previously reported for ICP-MS techniques. Our technique can also be applied to other environmental samples, including river, lake, and cave water samples.

Short-term exposure to reduced specific-size ambient particulate matter increase the risk of cause-specific cardiovascular disease: A national-wide evidence from hospital admissions

Evidence for the health effects of ambient PM1 (particulate matter with an aerodynamic diameter ≤ 1 µm) pollution is limited, and it remains unclear whether a smaller particulate matter has a greater impact on human health. We conducted a time-series study in 184 major cities by extracting daily hospital data on admissions for ischemic heart disease, heart failure, heart rhythm disturbances, and stroke between 2014 and 2017 from a medical insurance claims database of 0.28 billion beneficiaries. City-specific associations were estimated with over-dispersed generalized additive models. A random-effects meta-analysis was used to estimate regional and national average associations. We conducted stratified and meta-regression analyses to explore potential effect modifiers of the association. We recorded 8.83 million cardiovascular admissions during the study period. At the national-average level, a 10-μg/m3 increase in same-day PM1, PM2.5(particulate matter with an aerodynamic diameter ≤ 2.5 µm) and PM10(particulate matter with an aerodynamic diameter ≤ 10 µm) concentrations corresponded to a 1.14% (95% confidence interval 0.88–1.41%), 0.55% (0.40–0.70%), and 0.45% (0.36–0.55%) increase in cardiovascular admissions, respectively. PM1 exposure was also positively associated with all cardiovascular disease subtypes, including ischemic heart disease (1.28% change; 0.99–1.56%), heart failure (1.30% change; 0.70–1.91%), heart rhythm disturbances (1.11% change; 0.65–1.58%), and ischemic stroke (1.29% change; 0.88–1.71%). The associations between PM1 and cardiovascular admissions were stronger in cities with lower PM1 levels, higher air temperatures and relative humidity, as well as in subgroups with elder age (all P < 0.05). This study provides robust evidence of short-term associations between PM1 concentrations and increased hospital admissions for all major cardiovascular diseases in China. Our findings suggest a greater short-term impact on cardiovascular risk from PM1 in comparison to PM2.5 and PM10.

Association of ambient particulate matter with hospital admissions, length of hospital stay, and hospital costs due to cardiovascular disease: time-series analysis based on data from the Shanghai Medical Insurance System from 2016 to 2019

BackgroundThere is limited evidence supporting a relationship of ambient particulate matter (PM), especially PM1, with hospital admissions, hospital costs, and length of hospital stay (LOS) due to cardiovascular disease (CVD). We used a generalized additive model (GAM) to estimate the associations of these indicators due to CVD for each 10 μg/m3 increase in the level of PM1, PM2.5, and PM10, and the attributable risk caused by PM on CVD was determined using the WHO air quality guidelines from 2005 and 2021.ResultsFor each 10 μg/m3 increase in the level of each PM and for a 0-day lag time, there were significant increases in daily hospital admissions for CVD (PM1: 1.006% [95% CI 0.859, 1.153]; PM2.5: 0.454% [95% CI 0.377, 0.530]; PM10: 0.263% [95% CI 0.206, 0.320]) and greater daily hospital costs for CVD (PM1: 523.135 thousand CNY [95% CI 253.111, 793.158]; PM2.5: 247.051 thousand CNY [95% CI 106.766, 387.336]; PM10: 141.284 thousand CNY [95% CI 36.195, 246.373]). There were no significant associations between PM and daily LOS. Stratified analyses demonstrated stronger effects in young people and males for daily hospital admissions, and stronger effects in the elderly and males for daily hospital costs. Daily hospital admissions increased linearly with PM concentration up to about 30 µg/m3 (PM1), 60 µg/m3 (PM2.5), and 90 µg/m3 (PM10), with slower increases at higher concentrations. Daily hospital costs had an approximately linear increase with PM concentration at all tested concentrations. In general, hospital admissions, hospital costs, and LOS due to CVD were greater for PM2.5 than PM10, and the more stringent 2021 WHO guidelines indicated greater admissions, costs, and LOS due to CVD.ConclusionsShort-term elevation of PM of different sizes was associated with an increased risk of hospital admissions and hospital costs due to CVD. The relationship with hospital admissions was strongest for men and young individuals, and the relationship with hospital costs was strongest for men and the elderly. Smaller PM is associated with greater risk.

Bisphenol A (BPA) Directly Activates the G Protein-Coupled Estrogen Receptor 1 and Triggers the Metabolic Disruption in the Gonadal Tissue of Apostichopus japonicus.

The sea cucumber, Apostichopus japonicus, is a marine benthic organism that feeds on small benthic particulate matter and is easily affected by pollutants. Bisphenol A (BPA, 4,4'-isopropylidenediphenol) has been identified as an endocrine disruptor. It is ubiquitously detectable in oceans and affects a variety of marine animals. It functions as an estrogen analog and typically causes reproductive toxicity by interfering with the endocrine system. To comparatively analyze the reproductive effects of estradiol (E2) and BPA on sea cucumbers, we identified a G protein-coupled estrogen receptor 1 (GPER1) in A. japonicus and investigated its effects on reproduction. The results showed that BPA and E2 exposure activated A. japonicus AjGPER1, thereby mediating the mitogen-activated protein kinase signaling pathways. High-level expression of AjGPER1 in the ovarian tissue was confirmed by qPCR. Furthermore, metabolic changes were induced by 100 nM (22.83 μg/L) BPA exposure in the ovarian tissue, leading to a notable increase in the activities of trehalase and phosphofructokinase. Overall, our findings suggest that AjGPER1 is directly activated by BPA and affects sea cucumber reproduction by disrupting ovarian tissue metabolism, suggesting that marine pollutants pose a threat to the conservation of sea cucumber resources.

Spatial proximity to wildfires as a proxy for measuring PM2.5: A novel method for estimating exposures in rural settings.

Climate change impacts humans and society both directly and indirectly. Alaska, for example, is warming twice as fast as the global mean, and researchers are starting to grapple with the varied and inter-connected ways in which climate change affects the people there. With the number of wildfires increasing in Alaska as a result of climate change, the number of asthma cases has increased, driven by exposure to small particulate matter. However, it is not clear how far away smoke from wildfires can affect health. In this study, we hope to establish a relationship between proximity to wildfires and asthma in locations where direct PM2.5 measurement is not easily accomplished. In this study, we examined whether proximity to wildfire exposure is associated with regional counts of adults with asthma, calculated using Behavioral Risk Factor Surveillance System (BRFSS) survey data and US Census data. We assigned "hotspots" around population centers with a range of various distances to wildfires in Alaska. We found that wildfires are associated with asthma prevalence, and the association is strongest within 25 miles of fires. This study highlights the fact that proximity to wildfires has potential as a simple proxy for actual measured wildfire smoke, which has important implications for wildfire management agencies and for policy makers who must address health issues associated with wildfires, especially in rural areas.

S-23-1: OCCUPATIONAL AND ENVIRONMENTAL INFLUENCES ON HYPERTENSION

In this brief review I shall try to discuss several topics related to hypertension which maybe associated with occupational and environmental effects. Effects of dietary sodium will not be discussed as these are extensively discussed elsewhere. Occupational stress is difficult to define but there seems to be a relationship between high demands and relatively low control, and blood pressure in both men and women despite different professional distribution. Noise, a relatively less recognized stressor that may be associated with hypertension Both industrial noise and urban noise. Recently due to the Covid19 lockdown and reduction of aircraft noise in relevant areas a reduction of blood-pressure was noted. Seasonal variation with rise of blood pressure during cold and perhaps shorter daytime light seasons, and subsequent reduction in the summer with its higher temperatures and longer light hours is one environmental factor. Air pollution, especially that associated with high level small particulate matter equal to, or smaller than 0.25 μm, was associated with hypertension in several studies, with quite and ethnic and geographic variability. High altitude exposure (higher than 2500 m), involves hypoxemia (in addition to radiation, cold temperatures, and dehydration because of dryness of inhaled air), resulting in renin angiotensin system activation and sympathetically induced vascular contraction, and elevation of pulse rate and blood-pressure at rest and an exaggerated increase during exercise. Immigration seems to be associated with hypertension through different mechanisms in different populations. Mechanisms of these effects are not well understood though some must be mediated through sympathetic activation, others through the renin angiotensin system though, hypoxemia, altered redox state and inflammation all might participate along with other mechanisms

Hazed and Confused: The Effect of Air Pollution on Dementia

Abstract We study whether long-term cumulative exposure to airborne small particulate matter (PM2.5) affects the probability that an individual receives a new diagnosis of Alzheimer's disease or related dementias. We track the health, residential location, and PM2.5 exposures of Americans aged sixty-five and above from 2001 through 2013. The expansion of Clean Air Act regulations led to quasi-random variation in individuals’ subsequent exposures to PM2.5. We leverage these regulations to construct instrumental variables for individual-level decadal PM2.5 that we use within flexible probit models that also account for any potential sample selection based on survival. We find that a 1 µg/m3 increase in decadal PM2.5 increases the probability of a new dementia diagnosis by an average of 2.15 percentage points (pp). All else equal, we find larger effects for women, older people, and people with more clinical risk factors for dementia. These effects persist below current regulatory thresholds.

Eicosapentaenoic acid decreases APoC-III expression in response to air pollution particles in pulmonary endothelial cells

Background and Aims : Air pollution is the fourth leading contributor to global mortality. Small particulate matter (PM) specifically increases circulating triglyceride (TG) levels, a cardiovascular (CV) risk factor. Apolipoprotein C-III (ApoC-III) is associated with TG-rich lipoproteins and inhibits lipase activity, thus increasing TG levels. The omega-3 fatty acid, eicosapentaenoic acid (EPA), reduces TGs and events in patients with high CV risk (REDUCE-IT). We measured the effects of EPA on expression of ApoC-III in pulmonary endothelial cells (PECs) during exposure to finely-sized and urban-sourced PMs.

The Effect of Small Particulate Matter on Tourism and Related SMEs in Chiang Mai, Thailand

In northern Thailand, the problem of small particulate matter arises every year, with the primary source being agricultural-weed burning and wildfire. The tourism industry is strongly impacted and has been in the spotlight for the past few years. Thus, this study aims to investigate the effect of small particulate matter on tourism and related SMEs in Chiang Mai, Thailand. The data were collected from 286 entrepreneurs in the tourism and related SMEs sectors. The data were analyzed using data mining and association-rule techniques. The study revealed that small particulate matter has a considerable impact on customer factors, especially when the number of customers has decreased. Operational factors and product/service factors are also affected by the dust in the form of adjustments to keep the business running and the protection of the health of employees and customers. Certainly, financial factors are affected by the small particulate matter situation, both lower revenues and higher costs.