The continuous deterioration of air quality, the frequent occurrence and its following adverse effects of air pollution incidents have caused continuous public concerns. Therefore, achieving accurate prediction of air pollutants has significant role for governance efforts. In this paper, a combined weight forecasting model (CWFM) for NO2 concentration in Beijing is constructed based on three single

In this study, we demonstrate how under certain wind conditions, a mobile surface in situ platform, Truck MObile trace Gas (TMOG) Surveyor, that includes a ceilometer to derive boundary layer height (BL) can derive emissions. Field in situ and airborne thermal infrared imaging spectroscopy data were acquired by the thermal infrared imaging spectrometer, Mako, for three adjacent, central California

Previous studies in Addis Ababa, Ethiopia, focused on PM characteristics and sources, but PM's biological activity in this area has not been adequately investigated. In this study, cellular and acellular ROS activities were measured to assess PM toxicity. PM2.5 samples in Addis Ababa were collected from November 2015 to November 2016 and their chemical composition was analyzed (organic and elemental

Measurements of emissions of biogenic volatile organic compounds (BVOCs), solar global radiation, photosynthetically active radiation and meteorological parameters were carried out in a subtropical Pinus plantation, China during 2013–2016. The results were used to further develop and evaluate an empirical model of BVOC emissions (EMBE). Simulated BVOC emissions are in good agreement with observations

Determining land surface reflectance (LSR) is important for satellite retrieval of aerosol optical depth (AOD). Many studies have focused on the development of AOD retrieval through using different land surface reflectance determination algorithms. However, there is still lack of a comprehensive comparison among those algorithms. In this study, AOD retrieval algorithms with different land surface reflectance

To improve the atmospheric environment by optimizing urban morphology, this study develops a random forest (RF) model to investigate the influence of urban morphology on PM2.5 variations via the relative importance of urban morphology and the nonlinear response relationship between urban morphology and PM2.5. Two indices—reduction range (C↓) and rate (C˅) of PM2.5 concentrations—are defined to evaluate

The characteristics of atmospheric gaseous elemental mercury (GEM) in Hefei, China in winter, spring, and autumn 2016 were investigated in this study. Higher GEM concentrations in spring were associated with more abundant anthropogenic emissions and biomass burning before spring plowing. GEM concentrations in the three seasons decreased significantly compared to 2013–2014 levels (22.2%–49.2%), which

Driving cycles are important parameters to estimate vehicle emissions. However, most previous driving cycles, which were developed at the city scale or even national scale, cannot resolve the emission variations affected by road types and thus might introduce large uncertainties in the emission estimation. In this study, we proposed a new approach based on road type-based (RT-based) driving cycles

Low-molecular-weight carboxylates (LMWCs) are an important group of water-soluble organic compounds found in atmospheric aerosols, which have significant implications for environmental and human health. However, the relative importance of the different sources of LMWCs is poorly documented and evaluations of their effects on the free acidity of aerosols are scarce. This study reports on five LMWCs

To investigate the influence of pollution control on particulate matter with a diameter ≤2.5 μm (PM2.5), 40 samples were collected before and during the 2017 BRICS summit (BRICS) in an urban and a suburban area of the city of Xiamen, China. The average urban and suburban area PM2.5 concentrations during the BRICS were 26.3% and 35.9% lower than those before the summit, respectively. Chemical characteristics

In this study, PM2.5 and its chemical components were compared at an industrial site and a suburban site in Changzhou, China, during the winter of 2016. The average PM2.5 concentration was higher at the industrial site (113.06 ± 64.74 μg/m3) than that at the suburban site (84.75 ± 41.76 μg/m3), which suggests that severe pollution with higher emissions occurred in the industrial region. The ion balance

In this study, optical properties of aerosols were investigated from August 2012 to July 2013 in Nanjing, China. A three-wavelength photoacoustic soot spectrometer (PASS-3) was used to measure aerosol scattering and absorption coefficient (Bsca and Babs) with the wavelength dependence (405, 532, and 781 nm). The readings of PASS-3 agreed with those of the conventional instruments. The seasonal and

The World Health Organization has been making recommendations on assessing and monitoring air quality for human health protection. Its implementation implies a spatial distribution plan for air quality monitoring sites, especially in populated cities where high emissions of air pollutants with anthropogenic origin are observed. Therefore, the present study aimed: (i) to propose the spatial distribution

Air quality management is a serious challenge, especially in middle-income countries, where resources are limited and there are widely varying geographical, meteorological and economic conditions. In this study, air quality data obtained in the period January–April, from 2012 to 2019, were compared with the results obtained in 2020, to assess the impact of urban mobility restrictions on the emission

Residential wood combustion is, besides particulate emissions, also linked to emissions of organic compounds, comprising various toxic substances such as polycyclic aromatic hydrocarbons (PAHs). Although, literature data has shown that highest emissions occur during maloperations caused by the user itself, most studies focus on lab-testing not reflecting the situation in the field. This study evaluates

To study the effect of construction dust and agricultural fertilization on the chemical composition characteristics of precipitation during the summer in the Yangtze River Delta region (China), the chemical composition of 144 precipitation samples collected at Wuxi from June 6th to July 15th in 2016 was analyzed. The results demonstrated that the pH values varied from 4.72 to 7.08 for all the precipitation

The rapid development of fuel vehicles (FVs) exacerbated greenhouse gas emissions. The Chinese government launched a series of policies to promote battery electric vehicles (BEVs) to slow down the greenhouse effect. Zero emissions of BEVs have been achieved in the driving phase but not in the charging phase. Whether BEVs can achieve emission reduction needs to be further verified compared with FVs

A multi-instrument campaign was conducted to investigate the changes in ozone vertical distribution during the annular solar eclipse that occurred in the morning hours (08:10 to 11:15 Indian Standard Time) on 26 December 2016 using both in-situ and remote sensing observations over Gadanki, India (13.5oN,79.2oE). A series of ozonesondes were launched before and after the solar eclipse along with continuous

This paper analyses the characteristics of vertical electric field (Ez) fluctuations and their correlation with other quantities during haze event in Xi'an, China. Our results indicate that in regard to long-period fluctuations (period > 30 min), when the RH (relative humidity) change rate is positive at the development stage of haze event, secondary chemical reactions increase the PM10 (particulate

Wind erosion of soil is one of the most important sources of atmospheric particulate matter (PM). Determining the contribution of wind erosion of soil to the concentration of atmospheric PM is essential for the formulation of management strategies. In this study, we determined the contribution values (CVs) which denote the contribution of dust emissions to PM2.5 or PM10 levels, and the sharing rates

The contributions of emission reduction and meteorological changes to air quality improvement in Hubei Province (HB) have required assessment in recent years. In this study, the WRF-Chem scenario tests were conducted to evaluate the effect of both the emission and meteorological changes on the winter PM2.5 from 2015 to 2019, especially that of regional transport and local emissions on the PM2.5 variations

To study the spatial and temporal distributions of the near-ground concentration of fine particulate matter with an aerodynamic diameter smaller than 2.5 μm (PM2.5) in Anhui Province from 2017 to 2018, a remote sensing PM2.5 estimating model was constructed based on the generalized additive model (GAM) considering Himawari-8 aerosol optical depth (AOD), meteorological data, population density (POP)

The Government of the Republic of Korea has enforced strict regulations to improve air quality since the early 2000s. The regulations are mainly focused on reducing vehicle emissions in the Seoul metropolitan region by conforming to the European emissions standards, replacing diesel buses with compressed natural gas buses, incentives for installing diesel exhaust after-treatment systems and buying

The harm of acid rain (AR) to plants foliage is mainly manifested by changing their physiological and biochemical processes, such as chlorosis, nutrient loss, enzyme activity changes, etc., which in turn impacts plant growth. Since the types of AR in China is changing, the response of plants to different types of AR has become a research hotspot. In this research, we investigated the responses of Q

Limited research has been conducted in Asia on the association of maternal exposure to ambient air pollution and the increased risk of adverse pregnancy outcomes such as low birth weight and preterm birth. The aim of this study was to develop spatiotemporal land use regression (LUR) models for fine particulate matter (PM2.5) and nitrogen dioxide (NO2) in Chongqing, China, and to use the models to estimate

Selective catalytic reduction（SCR） technology is the key technology of flue gas denitration. SCR reactors are the systems contributing to pollution-free emission if they function properly. In order to study SCR denitration chemical reaction simulation and optimize the denitration effect, the CFD analysis of SCR reactor was carried out. The realizable k-ϵ turbulence model, component transport model

Evaluating the performance of air quality models for roadside traffic exhaust dispersion is critical to sustainable environmental development and urban pollution management. This study introduces three models, namely CAL3QHC, ENVI-met and ANSYS Fluent, to model the pollutant dispersion at an isolated busy urban signalized intersection, by taking fine particulate matter (PM2.5) as the subject matter

With the aim to meet ever-increasing strict regulations for three major exhaust gas pollutants, three-way catalytic technology has been effectively applied in automobile industries for purifying automobile exhaust gases. Here we report the efficiency of composite oxide Co3O4/TiO2 with the addition of CeO2 as a promotor. Modification of Co3O4/TiO2 (15 wt%. Co/TiO2) based composite catalyst synthesized

The main objective of the present study is to develop a model for the prediction of the extreme events of air pollution in megacities using the concept of so-called "natural time" instead of the "conventional clock time". In particular, we develop a new nowcasting technique based on a statistically significant fit to the law of Gutenberg-Richter of the surface concentration of ozone (O3), particles

Well integrity failure resulting in migration of natural gas outside of the surface casing can cause atmospheric greenhouse gas emissions and groundwater quality impacts from existing and historic energy wells. Spatial and temporal variability in gas migration can result in errors in detection (i.e., presence/absence) and efflux estimations. This field-based case study used automated dynamic closed

In this paper, we present validation of the cloud aerosol lidar with orthogonal polarization (CALIOP) level 1 and level 2 tropospheric aerosols products in coincidence to Micro Pulse Lidar (MPL) observations under different sky conditions and different seasons during March 2016–December 2018 over a tropical coastal station Kattankulathur (12.83oN, 80.04oE). In total, 33 simultaneous profiles during

The water solubility of potentially toxic elements is associated with biological effects and thus should be a major toxicity evaluation criterion for elements. The size distribution and potential health risk of particle-bound water-soluble metals (Cr, Ni, Zn, Fe, Pb, Ba, Mn, Cu, and Ti) in nine particle sizes (<0.43, 0.43–0.65, 0.65–1.1, 1.1–2.1, 2.1–3.3, 3.3–4.7, 4.7–5.8, 5.8–9, and >9 μm) were investigated

Otto cycle vehicles with gasoline direct injection (GDI) can reduce fuel consumption by 5–20%. In compliance with current legislation in Brazil, this technology was introduced to the domestic market in the form of a first flex-fuel GDI vehicle in 2013. However, despite gains in efficiency, studies in the literature have shown that GDI engines tend to have higher particulate matter emissions than port

We identified seven clusters from SMPS measurements ranging from 10 to 291 nm using k-means clustering, representing background (BG), local emissions (LocEm), two types of traffic emissions (TR), and three types of nucleation (NC). BG and LocEm differed in that pollutant concentrations were low and high, respectively, but both exhibited less pronounced diurnal variations in the frequency of occurrence

Regional ozone pollution has become one of the most challenging environmental problems in China. In July 2019, hourly real-time monitoring of ozone (O3) and nitrogen oxides (NOx) and 3-h off-line measurement of volatile organic compounds (VOCs) during a 10-day intensive campaign were conducted at four sites in Taiyuan, Shanxi Province, China. The average mixing ratio of total VOCs (including alkanes

Aerosols have severe effects on climate, human health and ecosystems. The impact of aerosols on climate, ecosystems and human health can be better understood if the variability of optical properties of aerosols is accurately known. In this paper, we have used Moderate Resolution Imaging Spectroradiometer (MODIS) datasets of aerosol optical depth (AOD) at 550 nm, Angstrom exponent (440/870) (AE) and

With increasing ozone pollution and deeper understanding of its harm to humans and climate, it is important to accurately forecast ozone. In this study, training and testing data sets were constructed with hourly numerical models forecasts and monitoring station observation for the year 2018 for Sichuan-Chongqing region, China. Three machine learning methods including Lasso, random forest and long