High Concentrations Of Particulate Matter Research Articles

Winter haze amplification by aerosol hygroscopic growth over eastern Indo- Gangetic Plain

Frequent occurrences of widespread winter haze over Northern India largely appear to originate from exceedingly high concentrations of fine particulate matter from anthropogenic emissions. However, the underlying mechanisms driving winter haze in Northern India are not well understood. This study employed a synergy of satellite and reanalysis data from 2006 to 2021 to assess the role of hygroscopic growth of aerosol optical depth in winter haze over the eastern Indo-Gangetic Plain. A method has been developed to extract dry aerosol optical depth from ambient aerosol optical depth to elucidate the origin of winter haze. About 31% of severe haze episodes (aerosol optical depth > 0.85) occurring under ambient humidity conditions decrease to below 5% for dry conditions, indicating the critical role of particle hygroscopic growth. The change in radiative forcing at the top of the atmosphere due to hygroscopic growth is relatively small compared to that at the surface and in the atmosphere, indicating enhanced atmospheric warming. The ubiquitous winter haze over the eastern Indo-Gangetic Plain is exacerbated by hygroscopic growth under high anthropogenic aerosol emissions, further aggravated through aerosol-radiation feedback. These results will be valuable in devising haze forecasts, implementing effective mitigation policies, and representing aerosol hygroscopicity in climate models.

Vocs pollution and respiratory exposure in commercial and residential underground parking garages

The indoor air quality in Underground Parking Garages (UPGs) has deteriorated significantly, primarily due to the high concentrations of particulate matter and volatile organic compounds (VOCs) emitted by idling or low-speed motor vehicles. However, the compositional characteristics and respiratory exposure to VOCs in UPGs have not been quantitatively analyzed. To establish a method for investigating the respiratory exposure to VOCs among different populations in UPGs, a three-dimensional dynamic diffusion model of indoor pollutants was developed based on monitoring data from 116 components in various UPGs in a large city in northern China. The results indicated that air pollution in underground spaces poses significant health risks to workers and children. Furthermore, a comprehensive approach is essential for improving ventilation capacity and air quality in underground transportation spaces.

Investigating the patterns of air pollution exposure on major cardiovascular events by cluster analysis. Insights from the EP-PARTICLES study on a Polish smog cohort

Abstract Introduction Exposure to air pollution (AP) is a modifiable risk factor for cardiovascular diseases. Aim To analyse the short-term effects of AP on the occurrence of acute coronary syndromes (ACS). Methods The EP-PARTICLES study consists of a retrospective nationwide cohort of Eastern Poland residents (N= 8,077,671). The area is characterized by a specific type of pollution - Polish smog, featuring high concentrations of particulate matter (PM), benzo(a)pyrenes (BaP) and favourable atmospheric conditions of formation. Medical data were collected from the National Health Fund and the Central Statistical Office. The records included sex and age and the causes of hospitalization. The analysis utilized air quality modeling data from the GEM-AQ system, which allowed to provide daily pollution concentration at the level of each LAU (ie. local administrative units, at municipality level), throughout the observation period. We estimated LAU specific associations of AP concentration using quasi-Poisson generalized additive models. We controlled our models for long-term trends and weather conditions. In the second stage, we pooled LAU-specific estimates with a random-effects meta-analysis. The results are presented as % risk ratio (RR), and 95% confidence intervals (95% CIs) for the two-day moving average of AP concentration on the present day and the day after exposure (ie. LAG0-1). Cluster analysis was performed on LAU levels from 19 variables using the k-mens clustering using the Ward minimum variance method. The set of variables included demographic, ecological, socioeconomic, environmental conditions. Results Over the years 2011-20, we noted 2,141,213 hospitalizations due to CVD, including 139,697 ACS cases (45.2% STEMI). The main triggers for ACS were PM2.5 (RRLAG0-1 1.04 95%CI 1.028-1.053), BaP (RRLAG0-1 1.021 95%CI 1.01-1.032). We identified three distinct clusters: Cluster 1 was characterized by high population density and GPD per capita and highest prevalence of atrial fibrillation. Cluster 2 (40% of the entire population) exhibited significantly high variability, characterized by low population density and GPD per capita, the highest prevalence of heart failure, people drinking alcohol and smoking tobacco. Cluster 3 (7% of the entire population) was in the middle but showed the highest prevalence of hypertension, diabetes and renal failure. Cluster 2 inhabited areas with low concentrations of PMs and BaP and demonstrated increased vulnerability to the effects of PM2.5 and BaP from 3% to 5.2% (P<0.001). For details see Figure 1. Conclusions PM and BaP are important factors associated with the occurrence of MACE. AP exposure should be considered in CVD prevention models. Cluster classification helps in risk stratification and prognosis. Adverse effects of AP can be mitigated by attention to improving socio-economic status and hazardous habits.Associations between AP exposure and ACS

Indoor air quality assessment of an existing apartment located in Indian tropical city, Bhubaneswar

Introduction: A proper investigation on indoor pollution level in economical apartments is important, where the provision for ventilation is limited. A series of experiments were conducted in the houses within an existing economical apartment in Bhubaneswar, India to evaluate various pollutant levels. Materials and methods: Temperature, relative humidity, CO, CO2, Particulate Matter (PM10 and PM2.5), Formaldehyde and Total volatile organic compounds in the bedrooms and kitchens are measured by pollution meters. The experiments were conducted with doors and windows closed conditions. The readings were taken on a four consecutive working day in February 2023 at an interval of 3 h (9:00 am to 9:00 pm). Results: The day wise temperature and humidity variations inside the bedroom and kitchen shows a reverse trend. At the afternoon, the indoor temperature becomes high, while during the night time humidity becomes the highest. The day wise indoor CO2 and CO variation trend is pretty similar. Both CO2 and CO concentrations in bedrooms are the highest in the evening. In contrast to that CO2 and CO concentrations in kitchens becomes maximum during noon time. High particulate matter concentration at outdoor and indoor is observed at the evening time. Higher formaldehyde (HCHO) and Total Volatile Organic Compounds (TVOCs) concentration at the indoor is observed at noon and afternoon time. Conclusion: The results obtained were compared with the recommended values of World Health Organization (WHO) and National Ambient Air Quality Standards (NAQIS). The results revealed that all measured parameters are at a higher level than the recommended values except the indoor CO2 concentrations.

Evaluating the impacts of printing operations on indoor air quality in a printing press

PurposeBuilding operations and human activities indoors continuously affect air quality, contaminating the air and sometimes exceeding permissible limits which can be health threatening either in the short or long time. This implies a need for strict awareness and compliance with air quality standards, particularly in workplaces prone to air contaminants emissions. This study aims to evaluate printing-related pollutant concentrations and their effects on indoor air quality (IAQ). The study investigated a printing press's total volatile organic compounds (TVOC), particulate matter (PM), carbon monoxide and carbon dioxide emissions.Design/methodology/approachThis study used mainly an experimental research design supported by physical assessment by identifying the major printing-related pollutants, assessing the existing situation and measuring pollutant concentration levels using literature reviews, walkthrough inspections and experiments, respectively. The measurements were conducted in two scenarios: with and without printing activities, and the results were compared with relevant standards and guidelines.FindingsThe outcomes indicate that TVOC concentration reaches 120 ppb during printing and binding activities, exceeding the 75 ppb acceptable limit based on the time-weighted average. The PM2.5 concentrations reach 49 µg/m3 and PM10 up to 150 µg/m3, exceeding acceptable levels given by the US Environmental Protection Agency (EPA), which are 35 µg/m3 and 150 µg/m3 for PM2.5 and PM10, respectively. These high concentrations of TVOC and PM indicate a significant risk to the health of building occupants, particularly those with respiratory conditions. PM concentrations do not exceed permissible levels when no printing or bookbinding occurs, suggesting that printing-related activities can contribute to elevated TVOC and PM concentrations.Social implicationsThe social implication of the study lies in its ability to promote awareness among workers and improve their well-being which in turn relates to productivity. The study outcome could also encourage businesses to adopt more responsible environmental and social practices as part of corporate social responsibility practices.Originality/valueThe study's findings, which highlight the need for improved ventilation in printing halls, have the potential to significantly benefit building system designers, facility managers, policymakers and decision-makers. By providing information and theoretical support, the research can help integrate policies that regulate IAQ by reducing pollutant concentrations. This protects workers' health and helps update and enforce stricter IAQ regulations for industrial operations.

Seasonal anomaly of particulate matter concentration in an equatorial climate: Evaluating the transboundary impact from neighboring provinces on Padang City, Indonesia.

This study investigated the anomalous seasonal variations in particulate matter (PM) concentrations-specifically PM2.5 and PM10-in Padang City, Indonesia, situated within the Equatorial climate zone. A one-year dataset of half-hourly PM measurements from January to December 2023, collected by the Air Quality Monitoring System (AQMS) managed by the Environmental Agency of West Sumatra (DLH), was utilized. Maps of hotspots and air mass backward trajectories were used to identify possible transboundary emissions affecting Padang City. Despite the region experiencing nearly continuous rainfall, significant elevations in PM levels were observed during the typically drier months of August to October. Specifically, PM2.5 levels peaked at 36.57µg/m3 and PM10 at 39.58µg/m3 in October, significantly higher than in other months and indicating a substantial deviation from the typical expectations for equatorial climates. These results suggest that the high PM concentrations are not solely due to local urban emissions or normal seasonal variations but are also significantly influenced by transboundary smoke from peatland fires and agricultural burning in neighboring provinces such as Bengkulu, Riau, Jambi, and South Sumatra. Backward trajectory analysis further confirmed the substantial impact of regional activities on degradation of air quality in Padang City. The study underscores the need for integrated air quality management that includes both local and transboundary pollution sources. Enhanced monitoring, public engagement, and inter-regional collaboration are emphasized as crucial strategies for mitigating the adverse effects of PM pollution in equatorial regions like Padang City.

Inter-annual changes in transboundary air quality from KORUS-AQ 2016 to SIJAQ 2022 campaign periods and assessment of emission reduction strategies in Northeast Asia

Northeast Asia suffers from high concentrations of particulate matter (PM), prompting nations to actively implement emission reduction policies. This study evaluated the recent inter-annual changes in the chemical transformation and transboundary transport of PM over Northeast Asia, based on both ground and aircraft measurements, as well as WRF-Chem simulations, during two comprehensive campaigns: the Korea–United States Air Quality (KORUS-AQ) campaign in 2016 and the Satellite Integrated Joint Monitoring of Air Quality (SIJAQ) campaign in 2022, both conducted around the Korean Peninsula. Ground measurements in 2022 revealed significant reductions in air pollutants compared to 2016 levels. In the Beijing–Tianjin–Hebei region, PM2.5 and SO2 concentrations decreased by 47.2% and 73.9%, respectively, attributable to successful SOx and NOx emission reduction strategies. Similar trends were observed in downwind areas, including Seoul, where PM2.5 and SO2 levels declined by 30.0% and 41.4%, respectively. WRF-Chem model results indicated substantial decreases in sulfates, nitrates, and their precursors in both surface and upper atmosphere in 2022 compared to 2016. Moreover, model-calculated gas-to-particle conversion ratios, which peaked in the Yellow Sea in 2016, decreased by 15% in 2022 and shifted slightly eastward to the western Korean Peninsula. This shift suggests a potential decline in secondary PM formation processed in the Yellow Sea, coinciding with reduced long-range transport of gaseous pollutants. A comparison of model sensitivity experiments, accounting for both bottom-up emission changes and meteorological variations, revealed that while weather and climate factors such as precipitation and pressure patterns between 2016 and 2022 contributed to the overall decrease in PM concentrations, the primary driver was the reduction in emissions during this period. This study highlighted that the main driver of the substantial improvement in air quality over East Asia was the implementation of emission reduction policies targeting PM and its precursors in the main source regions in China.

Estimation of human airway deposition of size-segregated particulate and their health impact in monsoon and post-monsoon season in semi-urban area of northern India

Numerous studies have shown the negative association between Particulate Matter (PM) exposure and health impact, understanding this risks associated with PM exposure for generating appropriate risk-control strategies, an accurate evaluation of PM concentration and respiratory deposition is necessary. So, the present study aims to describe the temporal and diurnal variation of Particulate Matter and Black Carbon concentrations, as well as their health risks. Real-time monitoring of PM and BC was conducted near a national highway (NH-19) in the semi-urban area. Our findings indicated that the washout effect played its role in reducing the PM level in monsoon season while meteorological parameters, local anthropogenic activities, and stubble-burning influenced the high PM concentration in the post-monsoon season. The current study also estimates the particle deposition in the human respiratory tract using Multiple Path Dosimetry Model (MPPD) for understanding the health effects of particle inhalation. The results revealed that different seasons exhibit different deposition patterns. For example, during the monsoon season, the trend was PM10>PM2.5>PM1.0 while in post-monsoon season PM2.5 >PM10 > PM1.0 respectively. The findings indicate that small particles easily deposited deeper into the lungs have a significant impact on various age groups, particularly children, who are the most affected. Furthermore, the health risks of PM and BC exceeded the safer limit (HQ = 1) and ELCR≥10−6, suggesting prolonged inhalation exposure to particulate could lead to cancer. The present study will give an insight into designing interventions and policies to control PM pollution in smaller cities, where a significant portion of the population resides.

-temporal variability in fire events due to crop residue burning and their impact on atmospheric variables using ground and remote sensingdata in Punjab

We attempted monitoring and mapping of the active fire events in Punjab, during the wheat and rice harvesting period of 2017-2021 from the Visible Infrared Imaging Radiometer Suite (VIIRS) at 375 m aboard. The analysis showed that the highest fire counts were observed in the central region, followed by the south-west and thelowest in the north-east region of Punjab during all the years. Moreover, during the wheat season, highest fire counts were observed in 2019, being 2535, 11062 and 6212 in north-east, central and south-west regions, respectively. However, during rice, highest fire counts were observed in 2020 in the north-east being 2857 and in 2021 the central and south-west regions being 40960 and 30351 respectively. In line with the number of fire counts, the highest concentration of gases and particulate matter obtained from the Central Pollution Control Board (CPCB) was also observed in the central zone. During the wheat harvesting season, central zone experienced the highest concentration of PM2.5 and PM10 in May 2018 and that of SO2 and O3 in May 2019. Similarly, during the rice harvesting season, central zone also experienced the highest concentration of PM2.5 and PM10 during November 2017 and that of SO2 in 2018. However, the highest concentration of NO2 was observed in October 2018 and that of O3 in October 2020 in the central region. Analysis of the concentration of NO2 and SO2 obtained from the Soumi-NPP satellite also had similar results to CPCB. Such a high concentration of gases and particulate matter might be attributed to crop residue burning a significant positive correlation was observed between fire counts and concentration of particulate matter (PM2.5 and PM10). In view of the alarming deterioration of air quality, there is a dire need to check this practice in the region by providing incentives and viable alternatives to the farmers.

Annual Variations of PM10, PM2.5 and PM1.0 Fraction at an Urban Site in Ansan, Korea

This study examines particulate matter (PM) concentrations, specifically PM10, PM2.5, and PM1.0, at an urban site in Ansan, South Korea. Three BAM-1020 continuous monitors measured PM10, PM2.5, and PM1.0 hourly from January to December 2021, with data acquisition rates of 97.1%, 97.3%, and 93.4%, respectively. Average annual concentrations were 45.7±48.4 µg/m³ (PM10), 26.4±22.7 µg/m³ (PM2.5), and 18.5±14.5 µg/m³ (PM1.0). PM10 was 91% of the annual air quality standard, while PM2.5 exceeded this standard by 176%, indicating severe pollution. Statistical analyses using probability density function (PDF) and cumulative distribution function (CDF) showed 98.5% of data converged at 150 µg/m³ (PM10), 75 µg/m³ (PM2.5), and 50 µg/m³ (PM1.0), with the remaining 1.5% corresponding to approximately 131 hours, annually. In 2021, all six observed yellow dust events occurred in spring (March to May). PM10, PM2.5, and PM1.0 concentrations increased from January to March, peaked in March, decreased until September, and rose again. The coarse fraction ratio increased stepwise from February to May, likely due to yellow dust and episodes of high PM concentration in the spring. The PM1.0 concentration was higher in summer and fall compared with that in spring and winter. The PM1.0/PM2.5 ratio was highest in summer and fall even though the annual PM1.0concentration was lowest, suggesting a higher secondary formation rate of fine particles during these periods. This underscores the need for further scientific investigation on PM1.0. The study provides insights into the simultaneous observation and distribution characteristics of PM10, PM2.5, and PM1.0, highlighting the mass concentration, distribution, and ratio of PM1.0. These findings are crucial for understanding PM distribution in Ansan, an industrial complex, and can serve as essential data for chemical composition comparisons, data validation, public health strategies, and cost-benefit analyses for regional PM improvement.

Ozone Induces Oxidative Stress and Inflammation in Nasal Mucosa of Rats

Background: The development of the global economy has led to changes in air pollution patterns. The haze phenomenon characterized by high concentrations of particulate matter 2.5 (PM2.5) has changed to complex pollution, and photochemical pollution characterized by ozone (O3) has become increasingly prominent. Ozone pollution and its impact on human health has become an important topic that needs to be studied urgently. Objective: To investigate the effects of ozone on oxidative stress and inflammation in the nasal mucosa of a rat model. Methods: Thirty-two healthy female Sprague–Dawley rats, eight in each group, were divided into four groups using the randomized numeric table method: normal control group (NC group), normal rats with a low level of ozone inhalation exposure (NEL group, 0.5 ppm), medium ozone inhalation exposure (NEM group, 1 ppm), and high ozone inhalation exposure (NEH group, 2 ppm). The ozone inhalation exposure groups were placed in the ozone inhalation exposure system and exposed to different concentrations of ozone for 2 h each day for 6 weeks. Nasal secretion was measured, and nasal lavage and nasal mucosa were collected. Malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) activities were measured by colorimetric assay, and the nasal mucosa was analyzed by Western blot. Western blot (WB) was used to detect the expression of NF-κB p65 nuclear protein in nasal mucosa. The mRNA expression of NF-κB target genes IL-6 and IL-8 and tumor necrosis factor-α (TNF-α) was detected by real-time quantitative PCR (qRT-PCR), and the protein content of pro-inflammatory factors IL-6, IL-8, and TNF-α was detected by ELISA in serum and nasal lavage fluid. The nasal mucosa of rats was stained with hematoxylin-eosin (HE) to observe the pathological changes in the nasal mucosa. The data were analyzed by SPSS 20.0 software. Results: The amount of nasal secretion increased significantly in all groups after ozone exposure compared with that in the NC group. The MDA content of the nasal mucosa was significantly increased in the ozone-exposed group compared with the NC group, and the activity levels of SOD and GSH-Px in the nasal mucosa were lower in the ozone-exposed group than in the NC group. The mRNA expression of IL-6, IL-8, and TNF-α in the nasal mucosa of the ozone-exposed group was elevated, and the protein content of TNF-α, IL-6, and IL-8 in the nasal lavage fluid was elevated, and the content increased with the increase in ozone concentration. The expression of NF-κB p65 intracellular protein in the nasal mucosa of each ozone-exposed group was higher than that of the normal group, and the content increased with the increase in ozone concentration. Conclusions: Ozone inhalation exposure promotes oxidative stress and the release of inflammatory factors TNF-α, IL-6, and IL-8, leading to pathological damage of the nasal mucosa, the degree of which increases with increasing concentration. This pathological process may be related to the activation of the transcription factor NF-κB by ozone in the nasal mucosa of rats, which increases the expression of its target genes.

Influence of meteorological conditions on the variability of indoor and outdoor particulate matter concentrations in a selected Polish health resort

The article evaluates air pollution by particulate matter (PM) in indoor and outdoor air in one of the Polish health resorts, where children and adults with respiratory diseases are treated. The highest indoor PM concentrations were recorded during the winter season. Therefore, the maximum average daily concentration values in indoor air for the PM10, PM2.5, and PM1 fractions were 50, 42 and 23 µg/m3, respectively. In the case of outdoor air, the highest average daily concentrations of PM2.5 reached a value of 40 µg/m3. The analyses and backward trajectories of episodes of high PM concentrations showed the impact of supra-regional sources and the influx of pollutants from North Africa on the variability of PM concentrations. The correlation between selected meteorological parameters and PM concentrations shows the relationship between PM concentrations and wind speed. For example, the correlation coefficients between PM1(I) and PM1(O) concentrations and wind speed were − 0.8 and − 0.7 respectively. These factors determined episodes of high PM concentrations during winter periods in the outdoor air, which were then transferred to the indoor air. Elevated concentrations in indoor air during summer were also influenced by chimney/gravity ventilation and the appearance of reverse chimney effect.

A novel method for establishing typical daily profile of PM concentrations in underground railway stations

The air quality in underground railway stations (URS) poses a significant public health concern due to extremely high concentrations of particulate matter: PM10 and PM2.5. Indeed, PM sources are strong and numerous, such as train braking and tunnel effect and URS are often confined spaces with low air change rates. Despite multiple PM measurements within URS, the variability of those concentrations from stations to stations is still poorly understood. We present here a methodology for establishing a daily profile of particle mass concentrations, based on a 5-year long measurement series in a Parisian URS. This approach incorporates an extensive data cleaning process based on the identification of URS operation periods and physically inconsistent or mathematically aberrant data, together with a linear regression model. This methodology delivers three usable outcomes: a typical profile for weekdays, a typical profile for weekends, and a PM concentration Daily Amplitude Coefficient (DAC) for the considered period. The DAC is a daily metric of the pollution levels, that enables the analysis of temporal trends and facilitates the comparison with other data with other acquisition frequency. The methodology developed here in a specific URS for PM10 measurements can be easily applied to different particle size fractions or to other measured parameters exhibiting a daily profile. Weekdays PM10 concentrations exhibit two distinct peaks corresponding to morning and evening rush hours, with an average daytime concentration of 193 µg/m³. These peaks are delayed by ∼1 hour compared to the train traffic. Weekends show consistently lower PM levels with no observable peaks, averaging 157 µg/m³ during the day. Our analysis reveals the long-term temporal evolution of PM concentration within the URS, highlighting seasonal patterns with higher PM10 concentrations observed in summer (up to 400 µg/m3) and lower values in winter (down to 250 µg/m3). This indoor seasonal evolution is not correlated with the outdoor temporal evolution, showing higher concentrations during the winter. Furthermore, our results show that the optimal period (DAC∼1) for conducting experiments to obtain reliable profiles is during the spring months (April, May, June).

Exposure to fine particulate matter in the New York City subway system during home-work commute.

The New York City (NYC) subway system accommodates 5.5 million daily commuters, and the environment within the subway is known to have high concentrations of fine particulate matter (PM2.5) pollution. Naturally, subway air pollution varies among individuals according to their mobility patterns, introducing the possibility of inequality in PM2.5 exposure. This study aims to evaluate individual and community-level exposure to subway PM2.5. We simulated the intracity home-to-work trip patterns using the Longitudinal Employer-Household Dynamics (LEHD) records of 3.1 million working commuters across 34,169 census blocks in four boroughs (Manhattan, Brooklyn, Queens, and the Bronx) of NYC. We incorporated the on-platform and on-train measured PM2.5 concentration data for the entire subway system. The mean underground platform concentration in the city was 139 μg/m3 with a standard deviation of 25 μg/m3, while the on-train concentration when underground was 99 μg/m3 with a standard deviation of 21 μg/m3. Using a network model, we determined the exposure of individual commuters during their daily home-work trips. We quantified the mean per capita exposure at the census block level by considering the proportion of workers within the blocks who rely on the subway for their work commute. Results indicate statistically significant weak positive correlation between elevated subway PM2.5 exposure and economically disadvantaged and racial minority groups.

Application of Acinetobacter indicus to promote cigarette smoke particulate matter phytoremediation: removal efficiency and plant-microbe interactions.

Particulate matter (PM) is one of the most hazardous atmospheric pollutants. Several plant species show high potential to reduce air pollutants and are widely used as green belts to provide clean outdoor spaces for human well-being. However, high PM concentrations cause physiological changes and stress in plants. In this study, 11 species of Thai native perennial plants were exposed to PM generated from tobacco smoke. Wrightia religiosa (Teijsm. & Binn.) Benth. ex Kurz, Bauhinia purpurea DC. ex Walp. and Tectona grandis L.f. reduced PM effectively (which is in the typical range of 43.95 to 52.97%) compared to other plant species. In addition, the responses of perennial plants under PM stress at the proteomic level were also evaluated. Proteomic analysis of these three plant species showed that plants respond negatively to high PM concentrations, such as reducing several photosynthetic-related proteins and increasing plant stress response proteins. To improve PM phytoremediation efficiency and reduce plant stress from PM, perennial plant-microbe interactions were investigated. W. religiosa was inoculated with Acinetobacter indicus PS1, and high biosurfactant-producing strains clearly showed a higher PM removal efficiency than non-inoculated plants (9.48, 9.5 and 12.6% for PM1.0, PM2.5 and PM10, respectively). Inoculating W. religiosa with A. indicus PS1 maintained chlorophyll a and b concentrations. Moreover, the malondialdehyde (MDA) concentration of W. religiosa inoculated with A. indicus PS1 was lower than that of non-inoculated W. religiosa. The leaf wax content (µg/cm2) and biosurfactant (µg/cm2) of W. religiosa inoculated with A. indicus PS1 were also higher than those of non-inoculated W. religiosa. This study clearly showed that inoculating plants with A. indicus PS1 can help plants remediate PM and improve their PM stress response.

Investigating the filtration performance and service life of vehicle cabin air filters in China

To protect occupants in vehicle cabin environments from the health risks of high concentrations of particulate matter (PM), it is important to install vehicle cabin air filter (VCAF) to eliminate PM. In this study, we investigated the filtration performance of 22 VCAFs. Results showed that the minimum average filtration efficiency was 56.1 % for particles with a diameter of 0.1–0.3 μm, a pressure drop of 33.2–250 Pa at air velocity of 2.5 m/s, and the dust-holding capacity ranged from 5.8 to 19.4 g. In addition, as the filter area increased from 0.23 m2 to 0.50 m2, the filtration efficiency for particles with a diameter of 0.1–0.3 μm increased from 56.7 % to 77.5 %, the pressure drop decreased from 96.1 to 62.5 Pa, and the dust holding capacity increased 2.7 times. Furthermore, we compared the service life of VCAF from 31 major Chinese cities and found that the service life varied greatly from maximum of 1730 h for Haikou to minimum of 352 h for Shijiazhuang. Considering occupant health risks, Beijing requires that VCAFs have PM2.5 filtration efficiency at least 88.1 %, and Liaoning requires minimum of 97.5 %. Hence, choosing the appropriate VCAF based on the atmospheric environment of different cities deserves our attention.

Patterns and disparities in indoor particulate matter levels in selected primary schools in Kigali, Rwanda

Air pollution is a global environmental and public health challenge. There is limited evidence about the air quality in Rwanda, and the concentrations of particulate matter (PM), namely PM2.5 and PM10 in schools have not been well documented. This study evaluated patterns and disparities in indoor PM levels in selected primary schools in Kigali, Rwanda.The study collected PM2.5 and PM10 concentrations from six classrooms in six selected primary schools during the regular school study period in the dry season. Data were collected using mobile air sensors (purple air/PA–II–SD air quality) and an observation checklist. A Kruskal-Wallis test was performed to assess the difference in PM2.5 and PM10 concentrations between the six schools. The post-hoc Mann-Whitney test was used to compare all group pairs.The results indicated a significant difference in both the indoor PM2.5 concentration (H (5) = 41.01, p < 0.001) and the indoor PM10 concentration (H (5) = 38.5, p < 0.001). The maximum concentration observed was 133.6 μg/m3 for PM2.5 and 158.5 μg/m3 for PM10. Schools in highly exposed areas tended to have higher concentrations of PM than schools in moderately exposed areas. Specifically, the daily average concentration of PM2.5 in schools located in highly exposed areas ranged from 39 μg/m³ to 118 μg/m³, while PM10 levels ranged from 44.0 μg/m³ to 126 μg/m³. In contrast, schools in moderately exposed areas had daily PM2.5 average concentrations ranging from 32.0 μg/m³ to 111.0 μg/m³ and daily PM10 average concentrations ranging from 38.0 μg/m³ to 119 μg/m³.Overall, the recorded values for both PM2.5 and PM10 in all sampled schools were higher than the World Health Organization air quality guidelines. Indoor air quality is poorer in schools situated in highly exposed areas. This study suggests interventions to improve school air quality for the benefit of school communities.

The impacts of reduction in ambient fine particulate air pollution on natural-cause mortality in Taiwan

ABSTRACT Many epidemiologic studies have reported an association between high concentrations of fine particulate matter (PM2.5) and increased mortality rates. Concurrently an association between decreased concentration of these airborne PM2.5 pollutants and a decline in mortality frequency was noted in certain investigations globally; however, only a very few of these studies were conducted in Asia. Taiwan was found to exhibit a 30% decline in ambient PM2.5 levels over the last 20 years. The aim of this ecological investigation was to examine the contribution of annual reductions in ambient PM2.5 to changes in age-standardized natural-cause mortality rates (ASRs) in 65 townships in Taiwan from 2006 to 2020 controlling for lung cancer mortality rate, physician density, and annual household income. Data demonstrated a 0.9/105 fall in adjusted ASR for every 10 ug/m3 reduction in mean annual PM2.5 level in Taiwan during this 14-year period, suggesting a significant association between reductions in ambient PM2.5 levels and decreases in natural-cause mortality rates.

Air Quality Monitoring with Low-Cost Sensors: A Record of the Increase of PM2.5 during Christmas and New Year’s Eve Celebrations in the City of Queretaro, Mexico

The high concentrations of particulate matter (PM) in the atmosphere have adverse effects on both the environment and human health, as well as on urban and faunal biodiversity. Short-term events, such as the burning of fireworks, attributable to human activity, result in a significant and rapid increase in PM concentration levels within the atmosphere. We present findings derived from observations made using low-cost PM sensors deployed as part of the Environmental Monitoring Network in Querétaro, Mexico. These sensors utilize the Environmental Geo Monitoring Stations (EMGA) device, developed by the Institute of Geosciences at UNAM. The observation period spanned from 10 December 2023 to 10 January 2024, encompassed the Christmas and New Year holidays, and focused on PM2.5 concentrations, and a comparison with a similar period from 10 February 2024 to 10 March 2024 considered a typical activity period in the area. The results reveal two substantial increases in PM2.5 concentrations (from less than 50 µg/m3 to more than 340 µg/m3) over time and spatial distribution during this period, with notable increases observed during the festive season coincident with the Christmas and New Year celebrations. Specifically, prolonged periods exceeding up to 6 h were noted on festivity days. This research offers insight into the effects, trends, and spatial–temporal distribution of pollutants within the city of Queretaro, which may be used as a reference for other cities around the world.

Fungal aerosol and particulate matter in horse stables in Poland

Horses stay in different types of stables; especially during the cold season, they stay inside for most of the day. A stable is also a place where many people spend quite a lot of time either as employees who care for and train horses or as equine enthusiasts. Keeping horses in stables causes their constant exposure to high concentrations of particulate matter (PM) and molds in the air inside these facilities. The study was conducted in Udórz Stud Farm located in the southern region of Poland. It was carried out in two different types of stables: three runners and two box stables. The study continued for 2 years; samples were collected in each season of the year. The following devices were used: a six-stage Andersen-Graseby cascade impactor, the DustTrak™ II Aerosol Monitor 8530. The obtained results allowed for the conclusion that horses kept in box stables are exposed to lower concentrations of molds and yeasts than those kept in runners. Molds dominated in the stable air during humid periods—spring and autumn—while yeasts were more prominent during summer and winter. It was observed that cleaning stables reduces the morphotic elements of fungi in the air, even though it results in a higher level of particulate matter in the stable air. It should be noted that microclimate conditions were optimal for horses practically throughout the whole year.Key points• In stables, there is a high level of air intoxication, both by yeast and by mold fungi• The concentrations of fungi in the air depend on the season and the stable cleaning procedure• The PM concentrations depend on the type of stable