Associations of long-term exposure to multiple air pollutants with chronic pain among middle-aged and older adults: a retrospective cohort study in China.
Long-term exposure to air pollution is a significant public health concern, yet its association with chronic pain remains underexplored, particularly regarding the combined effects of multiple pollutants. This retrospective cohort study investigated the link between long-term exposure to five air pollutants (PM₂.₅, PM₁₀, NO₂, SO₂, CO) and the incidence of chronic pain among middle-aged and older adults in China. Utilizing data from the China Health and Retirement Longitudinal Study from 2011 to 2020, this study included 10,378 participants free of chronic pain at baseline. Individual pollutant exposures were assessed and analyzed via time-dependent Cox and accelerated failure time models, integrated with Weighted Quantile Sum regression to evaluate mixture effects. During a mean follow-up of 7.39 years, 8,047 new-onset chronic pain cases were identified. Elevated concentrations of PM₂.₅, PM₁₀, SO₂, and CO were individually associated with increased chronic pain risk and shortened time to pain onset, with SO₂ showing the strongest effect. The combined exposure to all five pollutants was significantly associated with a higher risk and earlier onset of chronic pain, with SO₂ being the predominant contributor. This study reveals that long-term exposure to multiple air pollutants, especially SO₂, is significantly associated with an increased risk of chronic pain in middle-aged and older adults, underscoring the need for targeted air quality interventions to mitigate this health burden. PERSPECTIVE: This study identifies SO2 and CO as the principal driver within air pollutant co-exposure to increase chronic pain risk by mixture analysis. It provides direct evidence for revising air quality standards to target specific pollutants and mitigate the pain burden in aging populations.