Airborne microplastics (AMPs) present significant health risks indoors due to prolonged exposure. This study evaluates AMP concentration, types, and health impacts in residential, office, and commercial settings in Ahvaz, Iran, during winter and summer. The annual inhaled AMP dose was calculated based on typical occupancy patterns. AMP particles were collected from 30 locations using active sampling at 5 L/min for 8 h. Raman spectroscopy identified polymers, and SEM-EDX analysis examined surface morphology and elemental composition. The inhaled dose was estimated using MP concentrations and typical indoor exposure times. The highest AMP concentrations were in offices during winter (up to 48 MPs/m