Ambient air pollution and ocular surface squamous neoplasia: a case-control study in Tehran, Iran

To investigate the possible association between ambient air pollution (AAP) and odds of ocular surface squamous neoplasia (OSSN). A case–control study was conducted to evaluate associations between long-term exposure to ambient air pollutants and ocular surface squamous neoplasia (OSSN) that were diagnosed in Tehran from 2018 to 2024. The participants’ data including demographic characteristics, history of eye diseases and tumors, lifestyle-related factors, and length of residence in their current location were collected. Long-term exposure to ambient air pollutants before the diagnosis, was estimated based on land use regression (LUR) from 5-years ago. Logistic regression was applied to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs), with exposure–response relations examined using cubic spline functions. After adjustment for age and sex, each 10 µg/m³ increase in PM₂.₅ and each 10 ppb increase in SO₂ and O₃ were associated with increase (respectively 4.09 (95% CI: 1.65–10.14), 7.49 (1.64–34.26) and 3.86 (1.21–12.36)) in the odds of OSSN tumors. In further adjusted models, SO₂ (OR = 10.95; 95% CI: 2.06–58.27) and O₃ (3.81; 1.14–12.74) remained significantly associated with OSSN. Exposure–response analyses suggested mainly linear associations, with evidence of non-linearity for PM 2.5 , NO 2 , CO, and O 3 pollutants. Our findings show that exposure to ambient air PM 2.5 , SO 2 , and O 3 may be associated with higher odds of OSSN.