Development of a comprehensive air risk index and its application to high spatial-temporal health risk assessment in a large industrial city.

Particulate matter (PM) contains various hazardous air pollutants (HAPs) that can adversely affect human health, highlighting the need for an integrated index to represent the associated health risks. In response, this study developed a novel index, the comprehensive air-risk index (CARI), for Ulsan, the largest industrial city in South Korea. This index integrates toxicity-weighted concentrations of polycyclic aromatic hydrocarbons (PAHs) and heavy metals using their inhalation unit risks.

Mapping nationwide concentrations of sulfate and nitrate in ambient PM in South Korea using machine learning with ground observation data.

Particulate matter (PM) is a major air pollutant in Northeast Asia, with frequent high PM episodes. To investigate the nationwide spatial distribution maps of PM and secondary inorganic aerosols in South Korea, prediction models for mapping SO and NO concentrations in PM were developed using machine learning with ground-based observation data. Specifically, the random forest algorithm was used in this study to predict the SO and NO concentrations at 548 air quality monitoring stations located within the representative radii of eight intensive air quality monitoring stations.