Particulate Matter Exposure and Stress Hormone Levels: A Randomized, Double-Blind, Crossover Trial of Air Purification.

Cardiovascular Benefits of Fish-Oil Supplementation Against Fine Particulate Air Pollution in China

Background: Particulate matter (PM) levels in school classrooms represent a significant fraction of the daily exposure to air pollution among schoolchildren. PM levels may vary over time and may be influenced by a variety of environmental factors. However, previous studies on classrooms’ PM levels relied on short‐term measurements, while relevant data from Europe remain scarce. We aimed to prospectively monitor PM 2.5 (PM with aerodynamic diameter ≤ 2.5 μ m) and PM 10 (PM with aerodynamic diameter ≤ 10 μ m) levels in school classrooms and explore their relationships with outdoor and built environment characteristics, especially during teaching periods. By addressing PM exposure during teaching periods and evaluating the effects of mitigation measures, built characteristics, and environmental factors within primary school settings in Cyprus, this study fills critical gaps in understanding particulate exposure in educational environments. Methods: From March to June 2021, indoor PM 2.5 and PM 10 concentrations were assessed prospectively using optical particle sensors, in classrooms across nine primary schools in Nicosia, Cyprus. School hours were divided into distinct teaching and recess periods to study the variations in PM levels throughout the day, as well as the effect of outdoor sources. Indoor measurements were analyzed using 2‐min intervals. Corresponding time‐stamped data on outdoor air pollution were obtained from the nearest air quality station. Additionally, direct, on‐site comparison of indoor versus outdoor PM concentrations was possible using weekly gravimetric measurements by low‐volume Harvard samplers. Data on the built environment were collected from on‐site assessments and questionnaires. A linear mixed effects model was defined by fixed effects for the exposure variables and random intercepts to account for daily variations in PM levels, with additional variability between classrooms nested within each day. Results: Teaching periods, particularly after recess breaks, showed higher PM 10 (+28.2%) and PM 2.5 (+13.4%) levels than teaching periods before recess ( p < 0.001). Outdoor pollution had the most significant impact on indoor classroom PM 10 (+227.9%) and PM 2.5 (+84.3%) levels ( p < 0.001). Accessibility to soil yards led to substantially higher PM 10 (86.1%) and PM 2.5 (89.9%) ( p < 0.001). Classroom windows per square meter resulted in a 10.4% lower level of PM 10 , but a 5.5% higher level in PM 2.5 ( p < 0.05). Classrooms on upper floors were associated with 17.3% lower PM 10 levels ( p < 0.001). Both temperature and relative humidity were positively associated with PM levels ( p < 0.001). The use of air purifiers significantly reduced PM 10 and PM 2.5 levels by 43.5% and 30.4%, respectively ( p < 0.001). Conclusion: We demonstrated the significant impact of various factors on indoor PM levels in classrooms, including outdoor pollution, soil yard accessibility, and specific classroom characteristics. While air purifiers effectively reduce PM 10 and PM 2.5 levels, other factors such as teaching periods, temperature, and humidity also play critical roles, emphasizing the need for comprehensive air quality management strategies in schools.

Impact of short-term exposure to fine particulate matter air pollution on urinary metabolome: A randomized, double-blind, crossover trial

Estimation of personal PM2.5 and BC exposure by a modeling approach – Results of a panel study in Shanghai, China

Comparisons of commuter's exposure to particulate matters while using different transportation modes

Additional focus on particulate matter wash-off events from leaves is required: A review of studies of urban plants used to reduce airborne particulate matter pollution

Chinese college students’ physical activity mainly consists of physical activity in physical education (PE) classes and extra-curriculum physical activity. With the improvement of college PE teaching, as well as the decline of college students’ physique and the frequent occurrence of psychological problems in college students, more and more Chinese colleges has started promoting students’ active participation in physical activity. This is performed as a means of improving the physique and the mental health of college students. Flow is a positive psychological experience that quite often takes place in physical activity. Based on the theory of flow, this paper investigates flow characteristics in physical activity of college students in Shanghai. Contributing to existing literature on flow, this paper focuses on empirically exploring the manifestation of flow characteristics, differences in flow characteristics in different types of sports, and differences in flow characteristics in different grades of college students in Shanghai. The data are collected from questionnaire survey. Questionnaire questions are based on the Flow State Scale of Jackson and Marsh (1994). A preliminary test was carried out to assess the effectiveness of questionnaire questions. According to test results, a minor amendment of questionnaire questions was made to ensure that all questionnaire questions can be effectively understood. 500 questionnaires are handed out, and all were successfully retrieved. Factor analysis is utilized to reduce dimension, i.e., factorizing the answers to 36 questions into 6 variables and in calculating the value of flow. Test results found that the manifestation of flow characteristics in physical activity of college students in Shanghai are “self-experience”, “integration of action and awareness”, “clear goals and feedback”, “lack of self-consciousness”, “sense of control”, and “time transformation”. There are sharp differences between flow characteristics in physical activity of different types of sports. The flow in closed motor skills physical activity is higher than that in open motor skills physical activity. The main differences are manifested through four factors: self-experience, integration of action and awareness, clear goals and feedback, and sense of control. There are also significant differences among flow characteristics of college students in different grades, with freshmen having the highest value of flow. The flow characteristics of students in different grades also differ in terms of different types of sports.

Associations between high particulate matter (PM) pollution and increased morbidity and mortality from coronary heart disease have been identified. This study assessed leukotriene (LT) participation in PM-induced vascular endothelial dysfunction. Ten healthy males exercised 4 times for 30 min in both high PM (550,286 ± 42,004 particles·cm−3) and low PM (4571 ± 1922 particles·cm−3) after ingesting placebo (PL) or 10 mg montelukast (MK; half-life 3–6 h), a leukotriene receptor antagonist. Brachial artery flow-mediated dilation (FMD) was measured pre- and 30 min, 4 h, 24 h post-exercise. No basal brachial artery vascoconstriction was evident from high PM exercise. High PM blunted FMD, whereas high PM MK, low PM PL, and low PM MK demonstrated normal FMD (p < .003). Change in FMD (pre- to post-exercise) for high PM PL was different than for high PM MK, low PM PL, and low PM MK at 30 min post-exercise (p < .007). At 4 h, high PM MK FMD blunting increased (p = .1). At 24 h, high PM FMD blunting persisted (p < .05); no difference was observed between high PM PL or MK treatment, but was different that low PM PL/MK treatments (p < .05). MK blocked high PM post-exercise FMD blunting and maintained normal response, suggesting that leukotrienes are involved in PM-initiated vascular endothelial dysfunction.

Acute pancreatitis (AP) is a common abdominal inflammatory disease, which is mainly caused by gallstones, hyperlipidemia, and so on. Previous studies have explored the changes of serum metabolites in patients with AP. However, whether different etiologies have distinct impacts on the fecal and serum metabolites of the AP patients is still in suspense. This investigation was designed with dual objectives: (1) to systematically delineate etiology-specific alterations in metabolic profiles and associated pathway perturbations in AP cohorts, and (2) to evaluate their potential as diagnostic biomarkers and pathogenesis-targeted therapeutic strategies. Fifteen stool samples and fifteen serum samples from the patients with biliary acute pancreatitis (BAP) and hyperlipidemic acute pancreatitis (HAP), respectively, were analyzed. Metabolites were quantified by using ultrahigh performance liquid chromatography-mass spectrometry (UPLC-MS). The anti-inflammatory properties of Gibberellin A4 (GA4) and catechin were verified by RT-qPCR in vitro. The metabolites in feces and serum of the AP group were significantly different from that of the control group. Compared with the control group, a total of 10 fecal metabolites were significantly altered in the AP group. In the serum metabolites, five differential metabolites were identified between the AP and control groups. Receiver operating characteristic analysis of the subjects found that important differential metabolites can distinguish AP patients with different etiology from healthy people, and in vitro experiments found that GA4 and catechin could reduce the expression of inflammatory factors in pancreatic 266-6 cell line. The significant differential metabolites between AP patients and healthy people can clearly distinguish the two groups, and GA4 and catechin have anti-inflammatory effects on pancreatic cell lines. The identification of distinct metabolites enabled to distinguish the AP patients with different etiologies.

Source analysis of high particulate matter days in Hong Kong

Exposure to air pollutants has a direct impact on human health, resulting in increased mortality rates. Airborne particulate matter (PM) has major adverse effects on health and can be classified as high-risk respiratory particles (fine/PM2.5, aerodynamic diameter < 2.5 µm) or thoracic particles (coarse/PM10, aerodynamic diameter < 10 µm). In addition, airborne PM can carry microbial communities that alter the commensal microbiota and lead to dysbiosis. Our aim was to synthesize the current research evidence describing the association between air pollution exposure and the microbiome composition of the upper respiratory tract (URT) of the adult population. In this work, a systematic search of the PubMed, EMBASE and Scopus databases was conducted. A total of 9 studies published from 2018 to 2023 were included. 66.5% of the participants were exposed to PM2.5 concentrations higher than 40 µg/m3, and data showed that PM2.5 atmospheric levels were positively correlated with PM10 (rs = 0.95, p < 0.001). All the reviewed studies performed 16S rRNA sequencing of the V3–V4 region from URT samples, using different methods. Overall, evidence of URT microbiome alterations after high PM exposure was observed, with seasonal and geographical influence. Discordant findings were found about bacterial diversity, with a predominant decrease after exposure to high PM levels. Regarding microbiome composition, the relative abundance of the Actinobacteria phylum declined following exposure to high levels of PM, but that of Bacteroidetes and Fusobacteria increased. The studies showed a low-middle risk of bias due to heterogeneity regarding sample processing, sequencing methods, and confounder control. To confirm the observed evidence of an association between PM levels and alterations in the URT microbiome, we strongly recommend that future research work be conducted in accordance with standard guidelines for reporting microbiome studies. In summary, the entry of fine and coarse particles into the URT is associated with microbial dysbiosis, increasing the risk of developing respiratory diseases and allergies.Prospero registration: This systematic review was registered on PROSPERO (#CRD42023416230)Graphical

The effects of ambient particulate matter (PM) pollution on pneumonia in adults are inconclusive, and few scientific data on a national scale have been generated in low- or middle-income countries, despite their much higher PM concentrations. We aimed to examine the association between PM levels and hospital admissions for pneumonia in Chinese adults. A nationwide time series study was conducted in China between 2014 and 2017. Information on daily hospital admissions for pneumonia for 2014-2017 was collected from the database of Urban Employee Basic Medical Insurance (UEBMI), which covers 282.93 million adults. Associations of PM concentrations and hospital admissions for pneumonia were estimated for each city using a quasi-Poisson regression model controlling for time trend, temperature, relative humidity, day of the week, and public holiday and then pooled by random-effects meta-analysis. Meta-regression models were used to investigate potential effect modifiers, including cities' annual-average air pollutants concentrations, temperature, relative humidity, gross domestic product (GDP) per capita, and coverage rates by the UEBMI. More than 4.2 million pneumonia admissions were identified in 184 Chinese cities during the study period. Short-term elevations in PM concentrations were associated with increased pneumonia admissions. At the national level, a 10-μg/m3 increase in 3-day moving average (lag 0-2) concentrations of PM2.5 (PM ≤2.5 μm in aerodynamic diameter) and PM10 (PM ≤10 μm in aerodynamic diameter) was associated with 0.31% (95% confidence interval [CI] 0.15%-0.46%, P < 0.001) and 0.19% (0.11%-0.30%, P < 0.001) increases in hospital admissions for pneumonia, respectively. The effects of PM10 were stronger in cities with higher temperatures (percentage increase, 0.031%; 95% CI 0.003%-0.058%; P = 0.026) and relative humidity (percentage increase, 0.011%; 95% CI 0%-0.022%; P = 0.045), as well as in the elderly (percentage increase, 0.10% [95% CI 0.02%-0.19%] for people aged 18-64 years versus 0.32% [95% CI 0.22%-0.39%] for people aged ≥75 years; P < 0.001). The main limitation of the present study was the unavailability of data on individual exposure to PM pollution. Our findings suggest that there are significant short-term associations between ambient PM levels and increased hospital admissions for pneumonia in Chinese adults. These findings support the rationale that further limiting PM concentrations in China may be an effective strategy to reduce pneumonia-related hospital admissions.

BackgroundThe effects of ambient particulate matter (PM) pollution on pneumonia in adults are inconclusive, and few scientific data on a national scale have been generated in low- or middle-income countries, despite their much higher PM concentrations. We aimed to examine the association between PM levels and hospital admissions for pneumonia in Chinese adults.Methods and findingsA nationwide time series study was conducted in China between 2014 and 2017. Information on daily hospital admissions for pneumonia for 2014–2017 was collected from the database of Urban Employee Basic Medical Insurance (UEBMI), which covers 282.93 million adults. Associations of PM concentrations and hospital admissions for pneumonia were estimated for each city using a quasi-Poisson regression model controlling for time trend, temperature, relative humidity, day of the week, and public holiday and then pooled by random-effects meta-analysis. Meta-regression models were used to investigate potential effect modifiers, including cities’ annual-average air pollutants concentrations, temperature, relative humidity, gross domestic product (GDP) per capita, and coverage rates by the UEBMI. More than 4.2 million pneumonia admissions were identified in 184 Chinese cities during the study period. Short-term elevations in PM concentrations were associated with increased pneumonia admissions. At the national level, a 10-μg/m3 increase in 3-day moving average (lag 0–2) concentrations of PM2.5 (PM ≤2.5 μm in aerodynamic diameter) and PM10 (PM ≤10 μm in aerodynamic diameter) was associated with 0.31% (95% confidence interval [CI] 0.15%–0.46%, P < 0.001) and 0.19% (0.11%–0.30%, P < 0.001) increases in hospital admissions for pneumonia, respectively. The effects of PM10 were stronger in cities with higher temperatures (percentage increase, 0.031%; 95% CI 0.003%–0.058%; P = 0.026) and relative humidity (percentage increase, 0.011%; 95% CI 0%–0.022%; P = 0.045), as well as in the elderly (percentage increase, 0.10% [95% CI 0.02%–0.19%] for people aged 18–64 years versus 0.32% [95% CI 0.22%–0.39%] for people aged ≥75 years; P < 0.001). The main limitation of the present study was the unavailability of data on individual exposure to PM pollution.ConclusionsOur findings suggest that there are significant short-term associations between ambient PM levels and increased hospital admissions for pneumonia in Chinese adults. These findings support the rationale that further limiting PM concentrations in China may be an effective strategy to reduce pneumonia-related hospital admissions.

Particulate matter (PM) pollution has been increasingly becoming serious in Beijing and has drawn the attention of the local government and general public. This study was conducted during early spring of 2013 and 2014 to monitor the concentration of PM at three different land surfaces (bare land, urban forest, and lake) in the Olympic Park in Beijing and to analyze its effect on the concentration of meteorological factors and the dry deposition onto different land cover types. The results showed that diurnal variation of PM concentrations at the three different land surfaces had no significant regulations, and sharp short-term increases in PM10 (particulate matter having an aerodynamic diameter <10μm) occurred occasionally. The concentrations also differed from one land cover type to another at the same time, but the regulation was insignificant. The most important meteorological factor influencing the PM concentration is relative humidity; it is positively correlated with the PM concentration. While in the forests, the wind speed and irradiance also influenced the PM concentration by affecting the capture capacity of trees and dry deposition velocity. Other factors were not correlated with or influenced by the PM concentration. In addition, the hourly dry deposition in unit area (μg/m(2)) onto the three types of land surfaces and the removal efficiency based on the ratio of dry deposition and PM concentration were calculated. The results showed that the forest has the best removal capacity for both PM2.5 (particulate matter having an aerodynamic diameter <2.5μm) and PM10 because of the faster deposition velocity and relatively low resuspension rate. The lake's PM10 removal efficiency is higher than that of the bare land because of the relatively higher PM resuspension rates on the bare land. However, the PM2.5 removal efficiency is lower than that of the bare land because of the significantly lower dry deposition velocity.

Regional air quality over East Asia, including South Korea, has recently become a center of public attention because of a few episodes of very high particulate matter (PM) concentrations. Predicting PM variation with lead time of a few hours up to days is one of the key areas that the governments are working on because it can benefit from an early warning system to short‐term mitigation effort. In this study, the influence of synoptic weather conditions on regional air quality was investigated with the occurrence frequencies of PM episodes as a function of various synoptic weather patterns during winter and spring. During winter, dry moderate (DM) types occur frequently alongside high PM cases (24 hr mean PM10 concentration &gt;). The composite weather map showed a weak northwesterly wind field as a potential cause. On the contrary, it is interesting to note that dry polar types can be associated with low PM cases (24 hr mean PM10 concentration &lt;) as well as high PM depending on near‐surface wind speed. Furthermore, DM and dry tropical types were found to be highly correlated with high (higher) PM concentrations during spring season, likely because of the enhanced static stability in the lower troposphere. It should be noted that PM concentration depends on the lower atmospheric stability. The close relationship between synoptic weather patterns and PM concentration suggests that synoptic weather can play an important role in regional air quality.