Advances in Gaseous and Particulate Air Pollutants Measurement

1. Introduction

In recent years, notable advancements have been achieved in the science of aerosol and precursor gas measurements as well as the techniques used to apply them. These advances have led to a more thorough understanding of how aerosols and gases behave as primary and secondary air pollutants. Additionally, these improved monitoring techniques have enabled the detection and estimation of air pollutant behavior with higher accuracy, particularly in terms of spatial and temporal variations. Overall, these developments have substantially contributed to our knowledge of air pollution and its effects on the environment and human health.

2. Advances in Gaseous and Particulate Air Pollutants Measurement

This Special Issue covers a wide range of important topics related to monitoring techniques and methodologies in air quality research. The included papers address important areas such as the understanding of aerosol properties using multidimensional polarization scattering optical measurements, the estimation of emission factors for vehicle-emitted air pollutants in real-world conditions, the role of photochemical reactions in the formation of secondary products, the enhancement in low-cost sensors for air quality monitoring, the development of a multi-item air quality monitoring system, insights into airborne particle characteristics, the potential of convolutional neural networks for improving sensor performance, and the long-term trends in air pollutant concentrations and aerosol composition in northeast Asia.

In the first paper, the authors advance our understanding of aerosol properties through multidimensional polarization scattering optical measurements, with applications in atmospheric science, environmental monitoring, and pollution control. This study provides valuable insights into aerosol behavior and its various impacts [1]. The second paper introduces a novel method for estimating the emission factors of air pollutants emitted by vehicles in real-world conditions. This approach enables the cost-effective and short-term assessments of emission factors, facilitating the evaluation and implementation of traffic-related environmental policies [2]. The third paper highlights the role of photochemical reactions in the formation of secondary products, specifically addressing PM_2.5 pollution in agricultural regions. The findings contribute to an in-depth understanding of the underlying processes and can inform strategies for mitigating pollution and safeguarding human and environmental health [3]. In the fourth paper, the focus is improving the effectiveness of low-cost sensors for air quality monitoring by advancing calibration methods. This study supports air quality control efforts and promotes more reliable and accurate monitoring and management practices [4]. The fifth paper presents the development of a multi-item air quality monitoring system that enables the real-time monitoring of various parameters. The system includes a compact measuring device and a user-friendly smartphone application, providing convenient access to air quality information [5]. Insights into the characteristics of airborne particles are provided in the sixth paper, with an emphasis on the influence of traffic and potential transboundary effects on air quality. This study highlights the importance of continuous monitoring and further research to enhance air quality in the studied area [6]. The seventh paper describes the potential of convolutional neural networks in enhancing the performance of low-cost sensors for air quality monitoring. The researchers also investigated the impact of the COVID-19 lockdown on air pollutant concentrations, suggesting advancements in modeling and calibration techniques to improve the accuracy of air quality monitoring under different conditions [7]. The eighth paper focuses on analyzing the long-term trends in air pollutant concentrations and aerosol composition in northeast Asia. The study sheds light on the effects of emission changes in the region and provides valuable insights into the dynamics of air quality over an extended period [8].

Overall, this Special Issue encompasses a broad range of topics that contribute to the advancement of air quality research and provides valuable scientific findings for addressing environmental challenges and improving public health.