Association of long-term ozone air pollution and age-related macular degeneration in older Chinese population

Age-related macular degeneration (AMD) is the leading cause of legal blindness. It remains unclear whether and to what extent the ambient ozone pollution could increase the risk of AMD.

A nationwide cross-sectional survey was conducted in 129 major cities in 27 of 31 provincial regions across China from 2018 to 2021. Data in relation to demographics, residential address, and medical histories were collected. The exposure-response relationship between ozone exposure and AMD was explored using the restricted cubic splines. A piecewise logistic regression model was used to examine the magnitudes of the association, after adjusting demographic, social-economic and co-pollutants. Residential ozone exposures were estimated using a satellite-based model.

A total of 624,167 middle-aged and older participants were included in the final analyses, the overall prevalence of AMD was 16.76 %. The risk of AMD was consistently increasing with higher warm-season ozone concentration, and the risk became much larger after the cut-off of 110 μg/m³ (approximately 50 ppb). Every 10 μg/m³ increment in warm-season ozone concentration, the adjusted odds ratio (OR) for AMD were 1.15 (1.13, 1.16) and 1.66 (1.63, 1.69) when the warm-season ozone concentration was below or above 110 μg/m³, respectively.

This large-scale nationwide study provides the first epidemiological evidence demonstrating significant associations between long-term residential ozone exposure and AMD prevalence. Based on our findings, in conjunction with WHO global air quality guidelines, we suggest that a warm-season ozone of 110 μg/m³ should be adopted for middle-aged and older populations to reduce the risk of AMD. Ongoing efforts to reduce ozone exposure in communities through improved air quality regulations and public education are essential for the improvement of public health.