Objective Air pollution is a leading public health issue. This study investigated the effect of air quality and pollutants on pulmonary function and inflammation in patients with asthma in Shanghai.Methods The study monitored 27 asthma outpatients for a year, collecting data on weather, patient self-management [daily asthma diary, peak expiratory flow (PEF) monitoring, medication usage], spirometry and serum markers. To explore the potential mechanisms of any effects, asthmatic mice induced by ovalbumin (OVA) were exposed to PM2.5.Results Statistical and correlational analyses revealed that air pollutants have both acute and chronic effects on asthma. Acute exposure showed a correlation between PEF and levels of ozone (O3) and nitrogen dioxide (NO2). Chronic exposure indicated that interleukin-5 (IL-5) and interleukin-13 (IL-13) levels correlated with PM2.5 and PM10 concentrations. In asthmatic mouse models, exposure to PM2.5 increased cytokine levels and worsened lung function. Additionally, PM2.5 exposure inhibited cell proliferation by blocking the NF-κB and ERK phosphorylation pathways.Conclusion Ambient air pollutants exacerbate asthma by worsening lung function and enhancing Th2-mediated inflammation. Specifically, PM2.5 significantly contributes to these adverse effects. Further research is needed to elucidate the mechanisms by which PM2.5 impacts asthma.