Search Results (88)

Between 2013 and 2020, China had implemented a pilot cap-and-trade carbon emissions trading system (ETS) in some cities. Previous research has reported that this policy significantly reduces air pollution in the policy-implementing districts. However, whether and to what extent there are spatial spillover effects of this policy on air pollution in other regions has not been sufficiently analyzed. The research objective of this study is to quantitatively assess the spatial spillover effects of China’s carbon ETS on air pollution. Based on data from 288 Chinese cities between 2005 and 2020, this study employs a multiple linear regression approach to estimate the policy effects. Our study finds that the policy significantly reduces the concentrations of black carbon (BC), nitrogen dioxide (NO₂), organic carbon (OC), particulate matter less than 1 micron in size (PM₁), fine particulate matter (PM_2.5), and particulate matter less than 10 microns in size (PM₁₀) in non-ETS regions. This indicates that the carbon ETS has beneficial impacts on air quality beyond the areas where the policy was implemented. The heterogeneity tests reveal that the beneficial spatial spillover effects of the ETS can be observed across cities with different levels of industrialization, population density, economic development, resource endowments, and geographical locations. Further mechanism analyses show that although the policy does not affect the degree of environmental regulation in other regions, it promotes green innovation, low-carbon energy transition, and industrial structure upgrading there, which explains the observed spatial spillover effects. Full article

Background/Objectives: Inhaled corticosteroids (ICS) affect oxidative stress and systemic inflammation, which might modify the risk of thrombosis in asthmatic patients exposed to particulate matter with an aerodynamic diameter smaller than 2.5 microns (PM_2.5). Therefore, we aim to know the systemic biomarkers of oxidative stress, inflammation, and coagulation in ICS-treated, well-controlled adult asthmatic patients after exposure to PM_2.5. Methods: This study was conducted to compare urinary biomarkers of oxidative stress, i.e., 8-hydroxydeoxyguanosine (8-OHdG), and blood biomarkers of inflammation and hypercoagulation, i.e., complete blood count (CBC), high-sensitivity C-reactive protein (hsCRP), fibrinogen, D-dimer, tumor necrosis factor-alpha (TNF-α), and interleukins (IL-6 and IL-8), between well-controlled adult asthmatic patients and healthy controls in low and high-pollution periods. Results: Forty-one ICS-controlled asthmatic patients and twenty controls were included. Urinary 8-OHdG, white blood cells and differential counts, platelets count, hsCRP, IL-6, and IL-8 in the asthma group were not significantly higher than controls during the same period. The D-dimer level of the asthma patients was significantly higher than the controls (p < 0.05). The median level of TNF-α levels during the pollution period in asthma patients was significantly higher than the non-pollution period with levels of 14.3 (9.3, 27.4) and 11.3 (7.8, 21.1) pg/mL, p = 0.041, respectively. Conclusions: During exposure to PM_2.5, serum TNF-α was increased while the other markers of oxidative stress and inflammation were not high in ICS-treated asthma. ICS might mitigate PM_2.5-induced systemic oxidative stress, inflammation, and hypercoagulation in asthma. Full article

Heavy metals represent a class of pollutants detected at concentrations lower than 10 ppm in different matrices that are intensively monitored due to having a major impact on human health. Industrial activities including mining, agriculture, and transport, determine their presence in different environments. Corrosion phenomena of various installations, volcanic eruptions, or atmospheric deposition on the soil surface and in water can contaminate the respective environments. Atmospheric pollutants in the form of suspended dust particles with diameters below 10 microns are predominantly composed of different metallic species from Cd, Cr, Cu, Ni, etc. This paper presents a review of the main sources and types of heavy metals present in the atmosphere in the composition of particulate matter (PM), highlighting the main mechanisms of occurrence and detection techniques, including the impact on bio-geo-chemical processes in the soil and food chain, in close correlation with their impact on environment and human health. The purpose of this review is to highlight the current level of knowledge regarding the global situation of heavy metals in PM and to identify gaps as targets for future research. Full article

Climate change is one of the problems that affects the climate, natural disasters, and lives, economies, and industries around the world. Since the main cause is the combustion of fossil fuels, the transportation sector is a significant factor in causing these problems. Therefore, many countries, including Thailand, have policies to promote the increased use of electric vehicles. However, past measures have focused mostly on promoting the use of personal electric vehicles. For public transportation, buses are a major part of creating pollution and the problems of particulate matter with a diameter of less than 2.5-micron (PM 2.5), which is another major problem in Thailand because Thailand has many old buses. However, pushing transport operators to switch from internal combustion engine (ICE) buses to electric buses requires a large budget. Therefore, the conversion of old ICE buses into electric buses is one approach that can help promote the use of electric buses to become more possible. Another issue that makes transport operators afraid to switch from ICE buses to electric buses is the shortage of maintenance personnel. Therefore, this action research focuses on creating knowledge and practical skills related to electric vehicle modification and maintenance in the education sector. From the results of this practical research, the researcher was able to modify the old ICE bus into an electric bus and passed the test according to the research objectives. Full article

Stone mill operations contribute significantly to air pollution and increase health risks not only for workers but also for nearby communities. This study aimed to assess the health impacts of stone mill industries on nearby residents. The research was conducted in two areas: a primary region with a high number of stone mills and an area without stone mills. A questionnaire-based survey was employed, and potential health risks were evaluated using the hazard quotient (HQ) method. Total suspended particulates (TSPs) and particulate matter-10 micron (PM10) were analyzed as hazard factors based on monitoring data from seven stone mills collected between 2008 and 2021. The study found that residents in major stone mill areas reported higher hazard quotients (HQs) than those living farther from the mills, with a statistically significant association (p < 0.01). Seasonal variations also influenced dust distribution, with the highest TSP and PM10 levels recorded during winter, exacerbating health risks for local populations. This study highlights the need for improved community settlement planning, consideration of meteorological conditions, regulatory interventions by relevant agencies, and enhancements in environmental monitoring systems to mitigate the adverse health effects of stone mill operations. Full article

Nitrogen dioxide (NO₂) and particulate matter of 2.5 microns (PM_2.5) are air pollutants that impact health, especially among vulnerable populations with respiratory disease. This study identifies factors influencing indoor NO₂ and PM_2.5 in low-income households of older adults with asthma who use gas stoves in Lowell, Massachusetts. Environmental sampling was conducted in 73 homes, measuring NO₂, PM_2.5, fractional stove-use, temperature, and humidity for 5–7 days. Participants were recruited between December 2020 and July 2022. Questionnaires were used to collect data on factors influencing indoor NO₂ and PM_2.5 concentrations. Daily outdoor NO₂ and PM_2.5 concentrations were obtained from a United States Environmental Protection Agency (EPA) monitoring station. Paired t-tests were conducted between indoor and outdoor NO₂ and PM_2.5 concentrations, and linear regression was used to evaluate factors influencing indoor NO₂ and PM_2.5 concentrations. The average indoor concentration for NO₂ and PM_2.5 were 21.8 (GSD = 2.1) ppb and 16.2 (GSD = 2.7) µg/m³, respectively. Indoor NO₂ and PM_2.5 concentrations exceeded outdoor concentrations significantly. In multiple regression models, season and pilot light stove use significantly predicted indoor NO₂. Season and air freshener use for 6–7 days/week significantly predicted indoor PM_2.5. Season-influenced higher indoor concentrations are likely due to reduced ventilation in colder months in the Northeast U.S. Full article

The aim of this article is to analyse the global environmental impact of wind farms, i.e., the effects on human health and the local ecosystem. Compared to conventional energy sources, wind turbines emit significantly fewer greenhouse gases, which helps to mitigate global warming. During the life cycle of a wind farm, 86% of CO₂ emissions are generated by the extraction of raw materials and the manufacture of wind turbine components. The water consumption of wind farms is extremely low. In the operational phase, it is 4 L/MWh, and in the life cycle, one water footprint is only 670 L/MWh. However, wind farms occupy a relatively large total area of 0.345 ± 0.224 km²/MW of installed capacity on average. For this reason, wind farms will occupy more than 10% of the land area in some EU countries by 2030. The impact of wind farms on human health is mainly reflected in noise and shadow flicker, which can cause insomnia, headaches and various other problems. Ice flying off the rotor blades is not mentioned as a problem. On a positive note, the use of wind turbines instead of conventionally operated power plants helps to reduce the emission of particulate matter 2.5 microns or less in diameter (PM 2.5), which are a major problem for human health. In addition, the non-carcinogenic toxicity potential of wind turbines for humans over the entire life cycle is one of the lowest for energy plants. Wind farms can have a relatively large impact on the ecological system and biodiversity. The destruction of animal migration routes and habitats, the death of birds and bats in collisions with wind farms and the negative effects of wind farm noise on wildlife are examples of these impacts. The installation of a wind turbine at sea generates a lot of noise, which can have a significant impact on some marine animals. For this reason, planners should include noise mitigation measures when selecting the site for the future wind farm. The end of a wind turbine’s service life is not a major environmental issue. Most components of a wind turbine can be easily recycled and the biggest challenge is the rotor blades due to the composite materials used. Full article

Air pollution is recognized by the World Health Organization as the major environmental threat; therefore, air quality is constantly being monitored by monitoring stations. However, the most common atmospheric pollutants being monitored do not include pollen. Among the reasons for the lack of pollen control is that there are different types and sizes of pollen. The largest particles commonly being monitored by air monitoring stations have a maximum aerodynamic diameter of 10 microns, while the aerodynamic diameter of most pollen grains is known to range from 10 to 100 microns. For this reason, most pollen is not being detected by air monitoring stations. For the patents found in a literature review, monitoring pollen concentration in the air requires the discrimination of pollen grains from particulate matter of a similar size, as well as the identification of the type of pollen grains detected, since different pollen types may produce different effects, such as allergic reactions, asthma, and lung cancer, in exposed people. In this work, 15 patent documents regarding pollen monitoring were identified and reviewed using three search engines: Google Patents, WIPO’s PatentScope, and the United States Patent and Trademark Office (USPTO) database. The extracted data from the patents included whether they differentiate pollen type, pollen size, and sensor type and whether they provide real-time data. The results show that 93.33% of the patents identify pollen type, while 80% of the patents identify pollen size. Most of the patents use light-scattering and image sensors and use image processing techniques to analyze particles. Furthermore, 40% of the patents were found to implement artificial intelligence. Further, it was found that only nine patents provide real-time data, which is an important feature of an air monitoring system. Full article

Introduction: In Ethiopia, a comprehensive smoke-free law that bans smoking in all public areas has been implemented since 2019. This study aimed to evaluate compliance with these laws by measuring the air quality and conducting covert observations at 154 hospitality venues (HVs) in Addis Ababa. Methods: Indoor air quality was measured using Dylos air quality monitors during the peak hours of the venues, with concentrations of particulate matter <2.5 microns in diameter (PM_2.5) used as a marker of second-hand tobacco smoke. A standardized checklist was used to assess compliance with smoke-free laws during the same peak hours. The average PM_2.5 concentrations were classified as good, moderate, unhealthy for sensitive groups, unhealthy for all, or hazardous using the World Health Organization’s (WHO) standard air quality index breakpoints. Results: Only 23.6% of the venues complied with all smoke-free laws indicators. Additionally, cigarette and shisha smoking were observed at the HVs. Overall, 63.9% (95% confidence interval: 56–72%) of the HVs had PM_2.5 concentrations greater than 15 µg/m³. The presence of more than one cigarette smoker in the venue, observing shisha equipment in the indoor space, and the sale of tobacco products in the indoor space were significantly associated with higher median PM_2.5 concentration levels (p < 0.005). Hazardous level of PM_2.5 concentrations—100 times greater than the WHO standard—were recorded at HVs where several people were smoking shisha and cigarettes. Conclusions: Most HVs had PM_2.5 concentrations that exceeded the WHO average air quality standard. Stricter enforcement of smoke-free laws is necessary, particularly for bars and nightclubs/lounges. Full article

With the increasing application of semi-underground buildings, it is of greater significance to understand indoor air quality and personnel satisfaction in different functional areas within such buildings. In this study, a semi-underground building in Xi’an was taken as an example to test and study the indoor air quality in different functional areas, and a questionnaire survey based on the satisfaction of indoor personnel was conducted at the same time. The comprehensive results showed that the places with the highest concentrations of PM_2.5 exceeding the standard limit in the semi-underground building were the milk tea shops, hair salons, and driving schools, presenting 1.01 times, 1.15 times, and 1.08 times the standard limit, respectively. Hair salons were the sites with the highest pollution. The second most frequent pollutants were formaldehyde (HCHO) and total volatile organic compounds (TVOCs). In contrast to the wind speed parameters, the indoor concentrations of pollutants were higher than those outdoors. The upper limits of personnel satisfaction for particulate matter with a diameter less than 1.0 microns (PM_1.0), particulate matter with a diameter less than 2.5 microns (PM_2.5), and TVOCs were all higher than the standard limits. The upper limits of personnel satisfaction for PM₁₀, HCHO, wind speed, carbon monoxide (CO), and carbon dioxide (CO₂) were all below the standard limits. This provides data support and reference values for the widespread development and application of semi-underground buildings. Full article

This paper reports the successful fabrication of a new nanofibrous membrane, F-PI/PAN, through electrospinning of polyacrylonitrile (PAN) and fluorinated polyimide (F-PI). The nanofibrous membrane exhibits comprehensive properties for high-temperature filtration and robust PM_2.5 (particulate matter with an aerodynamic equivalent diameter of 2.5 microns or less) removal. The introduction of F enhances the hydrophobicity of the PI. The relationship between the hydrophobic performance and the filtration performance of particles is investigated. The chemical group of the composite membrane was demonstrated using FITR, while the surface morphology was investigated using field emission scanning electron microscopy. The TGA results indicated good thermal stability at 300 °C. Various ratios of F-PI membranes were prepared to characterize the change in properties, with the optimal mass ratio of F-PI being 20 wt%. As the proportion of F-PI increases, its mechanical and filtration efficiency properties and hydrophobicity become stronger. The contact angle reaches its maximum of 128 ± 5.2° when PAN:F-PI = 6:4. Meanwhile, when PAN:F-PI = 8:2, the filtration efficiency reaches 99.4 ± 0.3%, and the elongation at break can reach 76%. The fracture strength can also reach 7.1 MPa, 1.63 times that of the pure PAN membrane. Full article

Epidemiological studies have suggested that inhalation exposure to particulate matter (PM) air pollution, especially fine particles (i.e., PM_2.5 (PM with an aerodynamic diameter of 2.5 microns or less)), is causally associated with cardiovascular health risks. To explore the toxicological mechanisms behind the observed adverse health effects, the hemolytic activity of PM_2.5 samples collected during different pollution levels in Beijing was evaluated. The results demonstrated that the hemolysis of PM_2.5 ranged from 1.98% to 7.75% and demonstrated a clear dose–response relationship. The exposure toxicity index (TI) is proposed to represent the toxicity potential of PM_2.5, which is calculated by the hemolysis percentage of erythrocytes (red blood cells, RBC) multiplied by the mass concentration of PM_2.5. In a pollution episode, as the mass concentration increases, TI first increases and then decreases, that is, TI (low pollution levels) < TI (heavy pollution levels) < TI (medium pollution levels). In order to verify the feasibility of the hemolysis method for PM toxicity detection, the hemolytic properties of PM_2.5 were compared with the plasmid scission assay (PSA). The hemolysis results had a significant positive correlation with the DNA damage percentages, indicating that the hemolysis assay is feasible for the detection of PM_2.5 toxicity, thus providing more corroborating information regarding the risk to human cardiovascular health. Full article

Various shipping emission restrictions have recently been implemented locally and nationally, which might mitigate their impacts on regional air quality, climate change, and human health. In this study, the daily trace metal elements in PM₁ were measured in a coastal megacity in Northern China, from autumn to winter from 2018 to 2022, spanning DECA 1.0 (domestic emission control area), DECA 2.0, IMO 2020, and Pre-OWG Beijing 2022 stages. The trace element changes of V, Ni, Pb, and Zn in PM₁ were analyzed. The concentrations of V declined with shipping emission regulations implemented in 2018–2022 at 3.61 ± 3.01, 1.07 ± 1.04, 0.84 ± 0.62, and 0.68 ± 0.61 ng/m³, respectively, with the V/Ni ratio decreasing at 1.14 ± 0.79, 0.93 ± 1.24, 0.35 ± 0.24, and 0.22 ± 0.18. The V/Ni ratio was dominated by the shipping emissions in the DECA 1.0 stage but has been more affected by the inland sources since DECA 2.0. The V/Ni ratio of local transport air mass was higher than that of long-distance transportation, indicating that some ships were still using high-sulfur fuel oil, especially for the ships 12 nautical miles from the coastline. The multiple linear regression model showed a better fit using V as a tracer for ship emission sources of ambient SO₂ in the DECA 1.0 stage, while the indication effect reduced since DECA 2.0. The V and V/Ni ratios should be carefully used as indicators of ship sources as more vessels will use clean fuels for energy, and the contribution of inland sources to V and Ni will gradually increase. Full article

Characterizing the influence factors of exhaust gas based on the suspended road dust on paved roads, according to the number of vehicles and their distance with regard to driving pattern, is important in order to provide a coefficient for driving patterns to find a model equation. This has been a limitation of previous studies, in which this was difficult to carry out in a large area reflecting various driving patterns because some sections were selected according to empirical measurement results, and only one vehicle measurement was used to find the level of road dust. This study measured the concentration of suspended road dust that could occur, depending on the vehicle’s driving patterns, on an experimental road in Yongin, South Korea, from May to July 2023. The study was conducted to determine the degree of the effect of exhaust gas, according to the concentration of suspended road dust generated, by determining the separation distance based on real-time measurements. This study attempted to determine the changes in suspended road dust based on driving patterns in urban areas and factor in the concentration of suspended road dust with regard to emission characteristics in terms of exhaust gas and particulate matter with a diameter of 10 microns or less (PM₁₀). This was in accordance with conditions evaluated using mobile laboratories, based on suspended-PM₁₀-concentration-measuring equipment. This study mainly focused on the following main topics: (1) increasing the level of suspended particulate matter at less than 10 m intervals produced by exhaust gas; (2) decreasing the level of suspended road dust with an increase in the number of vehicles, with the area measured at a distance of three cars in front showing the lowest level of suspended road dust in the air and a low level for the rear vehicle; (3) demonstrating that PM₁₀ is effective in measuring the generation of suspended road dust; and (4) evaluating suspended road dust levels by road section. Based on the results, this research is necessary to more appropriately set the focus of analyses that aim to characterize suspended road dust according to exhaust gas and PM₁₀ content in silt. Full article

The removal efficiency of particulate matter of less than 2.5 microns (PM2.5) using an innovative wet scrubber tower with an IoT system for PM2.5 real-time monitoring was investigated. The PM2.5 used in this experiment was obtained from vehicle exhaust, specifically from running the diesel engine of a pickup truck with a range of PM2.5 with a concentration ranging from 50 µg/m³ to 500 µg/m³. Focused parameters related to PM2.5 were analyzed, such as the liquid-to-air ratio (it uses air because this device purifies PM2.5 for the airflow from the polluted ambient air), turbulence techniques enabled by the installation of a deflector and a baffle at the airflow inlet, water level fluctuation above the nozzle, spray nozzle size, and the type of packing material. The average PM2.5 removal efficiency was determined for each parameter relevant to the experiment. The results showed that increasing the liquid-to-air ratio increased the average PM2.5 removal efficiency, while the smaller droplet spraying water resulted in higher efficiency. The spray section achieved its highest efficiency at 58.63%, with a liquid-to-air ratio of 13.21 L/m³ and droplet size of 270 µm. The turbulence technique showed a higher potential for the removal of PM2.5, with an efficiency level of 71.56% at a water level of 150 mm. Moreover, the operation incorporates water spraying and turbulence induction, promoting higher removal efficiency, from 71.56% to 87.59%, at a water level of 150 mm and a liquid-to-air ratio of 9.03 L/m³. This condition resulted in an output concentration of PM2.5 less than 15 µg/m³, which meets the WHO’s guidelines for PM2.5 intensity. This cleverly designed wet scrubber tower can clean up to 13,320 m³ of air daily or remove up to 2,464 g of PM2.5 per day. No enhancement of PM2.5 removal efficiency was observed when two types of packing materials were used due to the formation of bigger droplets as the packing materials were passed through. Full article