Physicochemical characterization and cytotoxicity of ambient coarse, fine, and ultrafine particulate matters in Shanghai atmosphere

Epidemiological studies have demonstrated positive relationships between increases in air pollution and adverse health effects. Physicochemical characterization and toxicity of ambient coarse particles (1.8–10 μm diameter), fine particles (1.8–10 μm diameter) and ultrafine particles (<0.1 μm diameter) collected in Shanghai as major air pollutants were investigated. It was found that mass concentrations of different size ambient particles in Shanghai urban atmosphere were higher than those in suburban atmosphere. In addition, the mass concentrations among the different size particles were different. The coarse particles consisted of minerals, while the fine particles were mainly composed of soot aggregates and sulfates; ultrafine particles contained only small amounts of particulates. Crustal elements were mainly distributed in coarse particles, and the anthropogenic elements were mainly found in fine particles. Significant amounts of calcium and magnesium were found in ultrafine particles. Fine particles were found to generate more free radical than coarse and ultrafine particles. Moreover, the results of the cell proliferation assay indicated that ultrafine particles were more cytotoxic than fine and coarse particles. Further investigations are needed to study the mechanism of cytotoxic induced by the ambient particles.