Study on the Pollution Characteristics of Characteristic Elements in Atmospheric PM2.5 in a Special Region and Their Deposition Patterns in the Upper Respiratory System

The impact of PM2.5 on the environment and human health has garnered significant attention. While research on PM2.5 composition is increasing, fewer studies have focused on how dusty conditions in a special region affect the PM2.5 composition. This region’s unique environmental conditions, characterized by frequent dust events, complicate air quality management. The study investigates the seasonal distribution of inorganic elements in the PM2.5 under both dusty and non-dusty conditions through systematic sampling. Selective screening methods identified key pollutant elements, and a respiratory system model was developed to examine their diffusion and deposition patterns in the upper respiratory tract. Key findings reveal that inorganic element concentrations in the PM2.5 follow consistent seasonal trends, with significantly higher levels during dust events compared to non-dusty periods. Crustal elements are dominated in the PM2.5, but non-metallic elements (Cl, S) and metallic/quasi-metallic elements (Mn, Cd, Cr, As, Hg) are also prevalent, likely influenced by anthropogenic activities and industrial emissions. By PCA with human health assessments, six characteristic pollutants were identified: As, Co, Cd, Cr, V, and Mn. Simulations using COMSOL Multiphysics 6.2 software demonstrated distinct behaviors: As tends to concentrate in the posterior regions of the respiratory tract, while Co and Cd exhibit relatively uniform distributions, primarily affecting areas where airflow slows upstream. Cr, V, and Mn show dispersed and uniform patterns. Notably, even during dusty conditions, the concentration of the six pollutants remains relatively low in the different parts of the upper respiratory tract, suggesting minimal immediate health impacts. Our study provides valuable insights into the behavior of inorganic elements in the PM2.5 and their potential health implications, highlighting the need for further research on the effects of dusty conditions on air quality and public health.