成人的運動效益會被空氣污染削弱嗎？運動、PM2.5與死亡風險之敘述性綜論

Is the health benefit of exercise attenuated by air pollution in adults? A narrative review of exercise, PM2.5, and mortality risk

「運動的健康效益是否會被PM2.5削弱」已成為運動科學與公共衛生的重要議題。本文以綜論方式整合三類證據：風險-效益模型推估、不同地區之前瞻性世代研究，以及最新跨國系統性回顧、統合分析與個人層次數據合併分析。綜整結果顯示，風險-效益模型普遍指出隨PM2.5升高，成人戶外運動的健康效益可能遞減；但多數單一世代研究未發現顯著交互作用，僅少數研究呈現幅度較小的調節效果。相較之下，跨國大型整合證據提供較一致的訊息：在年平均PM2.5濃度達25μg／m³以上時，運動對降低全因死亡風險的保護效果可能幅度較小；在更高污染區間（約35-50μg／m³），其對癌症死亡風險的保護效果甚至趨於不顯著。整體而言，在中高污染環境下規律運動多仍具健康益處，但效益可能「打折」。因此，「規律運動+好空氣」方能讓民眾獲得最佳效益。建議民眾運動前查閱即時空氣品質，選擇較低污染時段與地點、調整運動型態與強度、必要時採行室內替代，以兼顧運動參與與長期健康。

Whether the health benefits of exercise are attenuated by exposure to PM2.5 has become an important issue in exercise science and public health. This narrative review integrates evidence from three sources: risk-benefit modeling studies, prospective cohort studies conducted in different regions, and recent large-scale international evidence, including systematic reviews, meta-analyses, and individual-level pooled analyses of cohort studies. Overall, risk-benefit models generally suggest that the health benefits of outdoor exercise in adults may decline as ambient PM2.5 concentrations increase. However, most individual cohort studies have not identified significant interaction effects between exercise and PM2.5 exposure, with only a few reporting minor moderations. In contrast, large international pooled evidence provides more consistent findings, indicating that when annual average PM2.5 concentrations exceed 25μg/m³, the protective effect of exercise on all-cause mortality is substantially reduced; at higher pollution levels (approximately 35-50μg/m³), the protective effect on cancer mortality may even become non-significant. Overall, regular exercise in moderately to highly polluted environments generally remain beneficial, although its health benefits may be attenuated. Therefore, optimal health benefits are best achieved through the combination of regular exercise and good air quality. Individuals are advised to consult real-time air quality information before exercising, select lower-pollution times and locations, adjust exercise type and intensity, and consider indoor alternatives when necessary to balance exercise participation and long-term health.