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In this study, a magnetic nanocatalyst (Fe3O4@SiO2@CeO2) was prepared and applied in the catalytic ozonation of methyldopa (MD). The effects of operational parameters on catalytic ozonation performance were investigated, including ozone dosage, catalyst dosage, initial MD concentration, and pH. The removal of MD was 45.2% in ozonation, whereas the efficiency was achieved to 83.0% with the addition of Fe3O4@SiO2@CeO2. The results showed that Fe3O4@SiO2@CeO2 could significantly improve the catalytic ozonation performance. And the enhanced mechanism study showed that it was attributed to promotion of ozone decomposition to generate hydroxyl radical. The reaction model was explored, and the reaction rates were calculated for the MD degradation in catalytic ozonation. A higher degradation efficiency of MD in catalytic ozonation was attributed to the enhanced surface effect of the catalysts, which was confirmed by using TBA, PO43−, and p‐BQ as scavengers of hydroxyl radical, surface reaction, and superoxide radical. The hydroxyl radical and superoxide radical played an important role in the degradation of MD. The mechanism of catalytic ozonation by Fe3O4@SiO2@CeO2 was discussed via X‐ray photoelectron spectroscopy (XPS) spectra and experimental data.

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Outdoor air pollution and particulate matter in polluted air are a class ofcarcinogens, and in recent years, atmospheric particulate matter pollution in China has remained at a high level. By reviewing the current situation of atmospheric particulate matter pollution in China and the research on the mechanism of particulate carcinogenesis, analyze the evidence of carcinogenicity of particulate matter in experimental animals in China and the epidemiological clues of particulate carcinogenesis, to explain the relationship between atmospheric particulate matter and cancer, and to propose relevant research in China.