Assessing the air quality performance of urban garden designs: an integrated ENVI-met modeling and field measurement study in Guelma, Algeria.

The purpose of the present work is to present results from a measuring campaign during February-March 2020, in Galati city, Romania, aiming the concentration of fine particulate matter (PM2.5) in air and their heavy metal concentrations, then comparing the results with the air quality determined by the national monitoring system from the same city. Results show considerable differences concerning the air quality measured in this study compared with measurements of the national monitoring system that consist in four stations placed across the city. While values recorded in this study exceeded, in some situations, the maximum target from PM2.5, the reports from the national monitoring system presented a good air quality, using a colour- and number-coding (maximum level 4 out of 6 was reported). Heavy metal concentrations of the fine particulate matters collected in this study was compared with other studies across the world, high Fe and Zn values being registered in agglomerated and industrialized cities, including the city considered in the present study, while in a study conducted in Beijing, China most higher values between all analysed heavy metals were recorded.

India's air pollution: a new government and global plan

<p indent=0mm>Carbon neutrality refers to achieving net-zero carbon dioxide emissions. Reducing CO₂ emissions is one of the major ways to achieve carbon neutrality and control air temperature rise. So far, numerous countries have pledged their goals of achieving carbon neutrality. In September 2020, China proposed a national dual-carbon goal and the associated timeline to achieve peak carbon and carbon neutrality. Therefore, how the proposal will lead to future changes in air quality and climate in China is of great interest. In the context of the dual-carbon goal, a series of emission reduction policies for different types of industries will be implemented to achieve CO₂ reductions. As a result, emissions of other pollutants will be reduced as well. Furthermore, future global climate change is also one of the main concerns. Most previous studies have focused on one single impacting factor without consideration of the dual-carbon goal. While carbon neutrality is an inevitable global trend, studies of its implication on air quality and climate change in China are still rare. Considering both regional emissions and global climate change will help predict future climate. Taking the dual-carbon goal into account will help adjust current emission reduction policies. In this study, we simulate the impacts of both regional emissions and global climate change in the future on China’s air quality and climate in the future under the dual-carbon goal scenario using a regional climate-ecology coupled model RegCM-Chem-YIBs, based on the Representative Concentration Pathway (RCP4.5) climate scenario and China’s 2030 emission data based on dynamics projection model (DPEC). Numerical simulations for present climate and present emissions, present climate and future emissions, and future climate and future emissions were performed. The comparison between the three sets of simulations provides how future regional emission reduction and global climate change will affect air pollution and climate in 2030. The study shows that, compared with 2015, the concentrations of fine particulate matter (PM_2.5), ozone (O₃), and carbon dioxide (CO₂) in China will decrease by approximately 36.8, <sc>19.8 μg m⁻³</sc> and <sc>1.9 ppm</sc> in 2030, respectively, under the combined effect of future regional emissions and global climate change. The temperature in the southern part of China will increase significantly, with an increase between 0.5 and <sc>1.5 K.</sc> Precipitation and clouds decrease by <sc>1−2 mm d⁻¹</sc> and <sc>3%−6%,</sc> respectively. The temperature in the northern part decreases slightly, generally below <sc>1 K.</sc> Precipitation and clouds increase by approximately 2 mm d⁻¹ and 6%, respectively. Overall, regional emission changes have a larger impact on PM_2.5, O₃ and CO₂ concentrations, which are the main influencing factors for future air quality changes, while global climate change has a greater impact on temperature, clouds and precipitation. Emission reduction policies under the dual-carbon target will significantly reduce air pollution, but may exacerbate warming at the surface because these policies will inevitably diminish the cooling effect of particulate matter. The mitigation of climate change will require GHG (greenhouse gas) and air pollution synergistic emission reduction policies and worldwide cooperation.

Fine particulate matter entering the body through breathing cause serious damage to humans. In South Korea, filter-type air purifiers are used to eliminate indoor fine particulate matter, and there has been a broad range of studies on the spread of fine particulate matter and air purifiers. However, earlier studies have not evaluated an operating method of air purifiers considering the inflow of fine particulate matter into the body or reduction performance of the concentration of fine particulate matter. There is a limit to controlling the concentration of fine particulate matter of the overall space where an air purifier is fixed in one spot as the source of indoor fine particulate matter is varied. Accordingly, this study analyzed changes in the concentration of indoor fine particulate matter through an experiment according to the discharging method and location of a fixed air purifier considering the inflow route of fine particulate matter into the body and their harmfulness. The study evaluated the purifiers’ performance in reducing the concentration of fine particulate matter in the occupants’ breathing zone according to the operation method in which a movable air purifier responds to the movement of occupants. The results showed the concentration of fine particulate matter around the breathing zone of the occupants had decreased by about 51 μg/m3 compared to the surrounding concentration in terms of the operating method in which an air purifier tracks occupants in real-time, and a decrease of about 68 μg/m3 in terms of the operating method in which an air purifier controls the zone. On the other hand, a real-time occupant tracking method may face a threshold due to the moving path of an air purifier and changes in the number of occupants. A zone controlling method is deemed suitable as an operating method of a movable air purifier to reduce the concentration of fine particulate matter in the breathing zone of occupants.

The COVID-19 pandemic commenced at the end of 2019, inducing a substantial decline in human activities across various sectors, encompassing industry, economy, tourism, and daily life globally. This resulted in a reduction in anthropogenic pollutant emissions.The concentration of fine particulate matter in the atmosphere incorporates influences from both artificial and natural emission sources. East Asia is also notable for experiencing frequent occurrences of yellow dust.Nonetheless, studies conducted by Bae et al. (2023) and Zhang et al. (2020) reported that PM10 concentrations in Korea and China decreased by more than 30% following the emergence of COVID-19. This phenomenon has been commonly observed worldwide.This study delves into whether air quality is deteriorating again now that the pandemic has subsided. It examines long-term changes in air quality in East Asia, covering the Pre-COVID-19 and Post-COVID-19 periods, utilizing measurement data. To enhance reliability, the data were obtained from a nationally operated atmospheric measurement station. In addition to PM10, changes in the concentration of gaseous pollutants such as NO2 and SO2 were also analyzed.In instances where changes in air quality occurred, an analysis was conducted to determine whether these changes correlated with human activities. The study explored whether yearly and seasonal weather changes acted as variables and whether air quality fluctuations in urban and rural areas exhibited disparities. Statistical methods such as regression analysis were employed.This study analyzes the impact of human activities on the concentration of fine particulate matter in East Asia and offers implications for the direction of national policies aimed at improving air quality.Reference:Minah Bae, Yoon-Hee Kang, Eunhye Kim, Segi Kim, Soontae Kim (2023), A multifaceted approach to explain short- and long-term PM2.5 concentration changes in Northeast Asia in the month of January during 2016&amp;#8211;2021, Science of the Total Environment, Volume 880, https://doi.org/10.1016/j.scitotenv.2023.163309Zhang, J., Cu i, K., Wang, Y.F., Wu , J.L., Hu ang, W.S., Wan, S., and Xu, K. (2020), Temporal variations in the air quality index and the impact of the COVID-19 event on air quality in western China, erosol and Air Quality Research, Vol. 20, No. 7, pp. 1552-1568. https://doi.org/10.4209/aaqr.2020.06.0297Acknowledgments:This research was supported by Particulate Matter Management Specialized Graduate Program through the Korea Environmental Industry &amp;amp; Technology Institute (KEITI) funded by the Ministry of Environment (MOE)

The purpose of this study was to survey the seasonal variation of fine particulate matter (PM2.5) concentration and determine spatial distribution in Darkhan city. Air pollution research and reports have been few and far between in most of parts in Mongolia, especially in Darkhan with respect to quantitative aerosol particle concentration. In this study, we utilized “PM2.5sensor” to measure spatial and seasonal variation of particulate matter concentrations in the study area. The monitoring points were chosen by basing on their specific features and set up directly at ambience outdoor. In each season, we carried out measurement at 3 points, which covered the ger district and apartment district areas for one day. Whereas, at one point the ger district was sampled for 4 days in summer. Fine particulate matter concentrations were the highest in the ger district area because there are many households that use coal for their daily heating and cooking, and at the bared surface. As for seasonal variation, in winter pollution reached 400 times higher than other seasons. Furthermore, at the ger district area, PM2.5 concentration was as much as 20 times greater than other points and it was observed that this too had its impact on the apartment district as well. As regards the air quality index, the level of particulate matter in the ger district area is extremely unhealthy to hazardous in winter. While, good and moderate indexes were mostly identified at monitoring points during the springtime.

Response of fine particulate matter and ozone concentrations to meteorology and anthropogenic precursors over the “2+26” cities of northern China

Characteristics of the large-scale circulation during episodes with high and low concentrations of carbon dioxide and air pollutants at an arctic monitoring site in winter

Indoor/outdoor relationship and chemical composition of fine and coarse particles in the southern California deserts

In this work, we intersect data on size-selected particulate matter (PM) with vehicular traffic counts and a comprehensive set of meteorological covariates to study the effect of traffic on air quality. To this end, we develop an M-quantile regression model with Lasso and Elastic Net penalizations. This allows (i) to identify the best proxy for vehicular traffic via model selection, (ii) to investigate the relationship between fine PM concentration and the covariates at different M-quantiles of the conditional response distribution, and (iii) to be robust to the presence of outliers. Heterogeneity in the data is accounted by fitting a B-spline on the effect of the day of the year. Analytic and bootstrap-based variance estimates of the regression coefficients are provided, together with a numerical evaluation of the proposed estimation procedure. Empirical results show that atmospheric stability is responsible for the most significant effect on fine PM concentration: this effect changes at different levels of the conditional response distribution and is relatively weaker on the tails. On the other hand, model selection allows to identify the best proxy for vehicular traffic whose effect remains essentially the same at different levels of the conditional responsedistribution.

Cardiovascular disease mortality and air pollution in countries with different socioeconomic status.

Schizophrenia episodes may be triggered by short-term environmental stimuli. Short-term increases in ambient air pollution levels may elevate the risk of schizophrenia episodes, yet few epidemiologic studies have examined this association. To investigate whether short-term increases in air pollution levels are associated with an additional risk of schizophrenia episodes, independent of absolute air pollution concentrations, and whether sustained increases in air pollution levels for several days are associated with more pronounced risks of schizophrenia episodes. This nationwide, population-based, time-stratified case-crossover study was performed based on hospitalization records for schizophrenia across 295 administrative divisions of prefecture-level or above cities in China. Records were extracted from 2 major health insurance systems from January 1, 2013, to December 31, 2017. Thirty-six cities with a small number of schizophrenia hospitalizations (n < 50) were excluded. Data analysis for this study was performed from January to March 2024. Daily absolute concentrations of fine particulate matter (PM2.5), inhalable particulate matter (PM10), nitrogen dioxide, sulfur dioxide, ozone, and carbon monoxide were collected. Air pollution increases between neighboring days (APINs) were generated as the differences in absolute air pollution concentrations on the current day minus that on the previous day. Sustained increases (APIN ≥5 μg/m3 for PM2.5 and PM10, APIN ≥1 μg/m3 for nitrogen dioxide and sulfur dioxide, and APIN ≥0.05 mg/m3 for carbon monoxide) lasting for 1 or more to 4 or more days were defined for different air pollutants. Patients with schizophrenia episodes were identified by principal discharge diagnoses of schizophrenia. A conditional logistic regression model was used to capture the associations of absolute concentrations, APINs, and sustained increase events for different air pollutants with risks of schizophrenia hospitalizations. The study included 817 296 hospitalization records for schizophrenia across 259 Chinese cities (30.6% aged 0-39 years, 56.4% aged 40-64 years, and 13.0% aged ≥65 years; 55.04% male). After adjusting for the absolute concentrations of respective air pollutants, per-IQR increases in 6-day moving average (lag0-5) APINs of PM2.5, PM10, nitrogen dioxide, sulfur dioxide, and carbon monoxide were associated with increases of 2.37% (95% CI, 0.88%-3.88%), 2.95% (95% CI, 1.46%-4.47%), 4.61% (95% CI, 2.93%-6.32%), 2.16% (95% CI, 0.59%-3.76%), and 2.02% (95% CI, 0.39%-3.68%) in schizophrenia hospitalizations, respectively. Greater risks of schizophrenia hospitalizations were associated with sustained increases in air pollutants lasting for longer durations up to 4 or more days. This case-crossover study of the association between ambient air pollution increases and schizophrenia hospitalizations provides novel evidence that short-term increases in ambient air pollution levels were positively associated with an elevated risk of schizophrenia episodes. Future schizophrenia prevention practices should pay additional attention to APINs, especially sustained increases in air pollution levels for longer durations, besides the absolute air pollution concentrations.

Characterization of chemical composition and concentration of fine particulate matter during a transit strike in Ottawa, Canada

In this study, we have focused on the outdoor concentration of fine particulate matter (PM2.5) during the coldest months (November-February) of 2016-2019 and January-February of 2020 and illustrated the daily, monthly and quarterly averages according to the single-point measurement data collected by the PM2.5 sensor at an air quality monitoring station located in a central area of Ulaanbaatar. The study also analyzes monthly high, low, average and median points of PM2.5 concentrations in the area that was selected. The PM2.5 sensor collects its data at an interval of every ten seconds, registers 8500 data in one day and presents the concentration of fine particulate matter in micrograms per cubic meter (μg/m3). On the basis of data collection and analysis, from November through February of 2019-2020, average PM2.5 concentration dropped noticeably by 44 per cent compared to the previous years. The Government of Mongolia took immediate action to combat air pollution of Ulaanbaatar city in May 2019 by banning the burning of raw coal in the ger districts, which account for 70 per cent of the city’s emissions, and introduced coal briquette as the only type of fuel that was allowed to be burned in metal stoves as a primary source of heating and cooking. Our study reveals that the latest government regulation had a considerable impact on air quality during winter 2019-2020 and helped in the sudden decline of the most dangerous pollutant PM2.5 concentration very close to national standards (50 µg/m3 24-hour mean) within 6 months since the enforcement of the new regulation.

Active travel (cycling, walking) is beneficial for the health due to increased physical activity (PA). However, active travel may increase the intake of air pollution, leading to negative health consequences. We examined the risk–benefit balance between active travel related PA and exposure to air pollution across a range of air pollution and PA scenarios.The health effects of active travel and air pollution were estimated through changes in all-cause mortality for different levels of active travel and air pollution. Air pollution exposure was estimated through changes in background concentrations of fine particulate matter (PM2.5), ranging from 5 to 200μg/m3. For active travel exposure, we estimated cycling and walking from 0 up to 16h per day, respectively. These refer to long-term average levels of active travel and PM2.5 exposure.For the global average urban background PM2.5 concentration (22μg/m3) benefits of PA by far outweigh risks from air pollution even under the most extreme levels of active travel. In areas with PM2.5 concentrations of 100μg/m3, harms would exceed benefits after 1h 30min of cycling per day or more than 10h of walking per day. If the counterfactual was driving, rather than staying at home, the benefits of PA would exceed harms from air pollution up to 3h 30min of cycling per day. The results were sensitive to dose–response function (DRF) assumptions for PM2.5 and PA.PA benefits of active travel outweighed the harm caused by air pollution in all but the most extreme air pollution concentrations.