Synergistic Characteristics of PM2.5 and O3 on the Development of Behavioral Guidance

Abstract：Objective: This study aims to establish time- and scenario-specific behavioral recommendations for vulnerable populations, based on the pollution characteristics and meteorological drivers of PM₂.₅ and O₃ in Luzhou (2016–2021), with the objective of mitigating health risks associated with air pollution. Methods: Hourly data on pollutants and meteorological factors were acquired from Luzhou Environmental Monitoring Station of Sichuan Province. After going through strict quality assurance and control procedures, an effective data collection rate of 96.6% was achieved, temporal distribution and influencing factors were analyzed. Results: A significant decreasing trend in PM₂.₅ concentrations was observed, whereas O₃ levels remained persistently elevated (194–213 μg/m³) during the observation period. PM₂.₅ levels peaked during winter nights (21:00–2:00), while O₃ concentrations were highest in the summer afternoons (14:00–15:00). which was closely related to the meteorological conditions (temperature and humidity) in this area. Conclusions: Although a reduction in PM₂.₅ levels, O₃ pollution continues to pose a significant challenge. It is recommended that outdoor activities be avoided during winter nights and outdoor exercise be minimized during summer afternoons. Vulnerable populations should limit prolonged exposure when O₃ concentrations exceed 160 μg/m³. These targeted behavioral interventions can effectively reduce acute exposure risks and contribute to public health management.