Association between Air Pollution and Physical Activity and Sedentary Behavior among Adults Aged 60 Years or Older in China: A Cross-Sectional Study

Background: Exposure to air pollution is associated with an increased risk of all-cause mortality in older adults. Promoting physical activity (PA) and avoiding sedentary behavior (SB) serve as key strategies to maintain and improve human health. However, ambient air pollution can adversely affect PA and SB, increasing the risks of health problems. This study aimed to visualize national spatial patterns of average AQI concentration, PA, and SB distributions and to examine the associations between air pollution and PA and SB in a national sample of Chinese older adults aged 60 years or older. Methods: We analyzed the data of the China Longitudinal Aging Social Survey 2020 (CLASS 2020), which sampled 11,399 older men and women from 30 cities in China. Moderate, vigorous, and light PA and SB were measured using the Chinese version of the International Physical Activity Questionnaire-Short Form (IPAQ-C). The environmental measures included the average hourly air quality index (AQI), PM_2.5, PM₁₀, and NO₂ (µg/m³). The data were analyzed using multivariable linear regression. Results: Increases in the standard deviations (±SD) of AQI, PM_2.5, PM₁₀, and NO₂ concentrations were associated with decreases in MVPA per week of −2.34 (95%CI = −3.36, −1.32), −2.58 (95%CI = −3.61, −1.55), −1.96 (95%CI = −3.05, −0.08), and −1.19 (95%CI = −2.06, −0.31) and decreases in LPA per week of −6.06 (95%CI = −7.15, −4.97), −4.86 (95%CI = −5.88, −3.85), −4.78 (95%CI = −5.89, −3.68), and −4.59 (95%CI = −5.57, −3.61) h/week, respectively. Increases in one SD of AQI, PM_2.5, PM₁₀, and NO₂ were associated with increases in SB per week of 1.32 (95%CI = 0.77, 1.88), 0.62 (95%CI = 0.09, 1.14), 1.03 (95%CI = 0.48, 1.59), and 0.98 (95%CI = 0.46, 1.49) h/week, respectively. Conclusions: The spatial distributions of the average AQI concentration, MVPA, LPA, and SB are useful and allow environmental and health policymakers to identify the areas with the highest priority air pollution environmental equality concerns. AQI was positively associated with MVPA and LPA, and it was negatively associated with SB among older adults. AQI, PM_2.5, PM₁₀, and NO₂ were hardly associated with women’s average time spent engaged in MVPA. Region-specific and multi-level health policy options are needed to reduce ambient air pollution by taking different types of pollutants into account in order to avoid changes in PA and SB in this population, especially in locations with high air pollution concentrations.