Physical and chemical characteristics of PM and its toxicity to human bronchial cells BEAS-2B in the winter and summer.

With the increasing occurrence of haze during the summer, the physicochemical characteristics and toxicity differences in PM in different seasons are of great concern. Hangzhou is located in an area that has a subtropical monsoon climate where the humidity is very high during both the summer and winter. However, there are limited studies on the seasonal differences in PM in these weather conditions. In this test, PM samples were collected in the winter and summer, the morphology and chemical composition of PM were analyzed, the toxicity of PM to human bronchial cells BEAS-2B was compared, and the correlation between PM toxicity and the chemical composition was discussed. The results showed that during both the winter and summer, the main compounds in the PM samples were water-soluble ions, particularly SO, NO, and NH, followed by organic components, while heavy metals were present at lower levels. The higher the mass concentration of PM, the greater its impact on cell viability and ROS levels. However, when the mass concentration of PM was similar, the water extraction from the summer samples showed a greater impact on BEAS-2B than that from the winter samples. The cytotoxicity of PM was closely associated with heavy metals and organic pollutants but less related to water-soluble ions.