Abstract
While ambient air pollution is a recognized risk factor for various diseases, its specific link to esophagitis and esophageal ulcer remains poorly understood. Similarly, the potential role of residential water space is unclear. This study aimed to examine the individual and combined associations of ambient air pollution and residential water space with the risk of esophagitis and esophageal ulcer. We included 399,766 UK Biobank participants who were free of these conditions at baseline. Incident cases were identified via hospital records using ICD-10 codes (K20, K21.0, and K22.1). Exposures to ambient air pollutants (PM2.5, PMcoarse, PM10, NO2, and NOx) and residential water space (at 300 m and 1000 m buffers) were estimated using land-use regression models and spatial datasets. Cox proportional hazards models revealed that higher exposures to PM2.5 (HR = 1.14; 95% CI: 1.10-1.19), NO2 (HR = 1.10; 95% CI: 1.06-1.15), and NOx (HR = 1.17; 95% CI: 1.12-1.22) were associated with an increased risk of esophagitis and esophageal ulcer. Conversely, greater exposures to water space at both 300 m (HR = 0.94; 95% CI: 0.91-0.98) and 1000 m (HR = 0.91; 95% CI: 0.88-0.95) buffers were associated with a reduced risk. Mediation analyses indicated that 10.49% to 43.03% of the inverse association between water space and esophageal outcomes was statistically mediated by attenuated exposure to PM2.5 and NOx. These findings suggest that PM2.5, NO2, and NOx are associated with an elevated risk of esophagitis and esophageal ulcer, whereas residential water space is associated with a reduced risk.