Association between long-term exposure to ambient air pollution and an increased risk of steatotic liver disease

Steatotic liver disease (SLD), the most common chronic liver disease, imposes significant health and economic burdens. This study examined the association between long-term exposure to ambient air pollutants and SLD risk and severity in a population with relatively lower pollution levels. We analyzed 20,553 participants who underwent health screening from 2015-2019. Five-year exposures to PM_2.5, PM₁₀, NO₂, SO₂, and CO were estimated using nationwide monitoring data and modeled concentrations. SLD was diagnosed using ultrasonography and graded as mild, moderate, or severe. Multivariate and ordinal logistic regression analyses were used to evaluate the associations among air pollutant exposure, SLD risk, and severity. An interquartile range increase in 5-year pollutant exposure was associated with increased SLD risk: PM_2.5 (OR: 1.04, 95% CI: 1.01-1.07), PM₁₀ (OR: 1.06, 95% CI: 1.01-1.11), NO₂ (OR: 1.10, 95% CI: 1.04-1.16), and CO (OR: 1.07, 95% CI: 1.02-1.12). Additionally, PM_2.5, NO₂, and CO exposure was associated with greater SLD severity. Subgroup analyses revealed heightened susceptibility in individuals with a higher body mass index and waist circumference. These findings suggest that even modest increases in air pollutant concentrations are associated with a higher SLD risk and severity, particularly in metabolically vulnerable individuals.