Indoor particulate matter exposure and ocular damage: Toxicity mechanisms and mitigation strategies

Indoor particulate matter (PM) has emerged as a significant environmental risk factor for ocular health, yet the molecular mechanisms underlying PM-induced eye damage remain poorly understood. This review aims to synthesize current knowledge on the sources, molecular pathways, and mitigation strategies of indoor PM, with a focus on its ocular toxicity. Recent studies highlight that PM_2.5, due to its small size and high surface-to-volume ratio, penetrates ocular tissues, triggering oxidative stress, endoplasmic reticulum stress, and mitochondrial dysfunction. These processes are key drivers of chronic inflammation and cell death, contributing to conditions such as dry eye disease, glaucoma, and age-related macular degeneration. Notably, ferroptosis, an iron-dependent cell death pathway, has been identified as a critical mechanism in PM-induced retinal damage, offering novel therapeutic targets. Seasonal variations in PM composition further influence its cytotoxicity, with winter PM exhibiting heightened inflammatory potential. To mitigate these risks, a multi-faceted approach combining key pollutants identification, source reduction (e.g., clean energy adoption), engineering controls (e.g., air purifiers), and policy initiatives (e.g., China’s "Coal-to-Gas" program) has demonstrated efficacy in reducing PM-linked ocular disorders. This review underscores the need for interdisciplinary collaboration to translate mechanistic insights into practical interventions, ultimately safeguarding eye health in polluted environments.