Common sources of indoor air pollution include household cleaning products, tobacco smoke, pet dander, mold, and mildew. Other contributors are volatile organic compounds (VOCs) from paints, solvents, and air fresheners, as well as combustion pollutants from stoves, fireplaces, and heating systems. Poor ventilation can exacerbate the concentration of these pollutants. Additionally, outdoor pollutants like pollen, dust, and vehicle emissions can enter the home and impact indoor air quality. Regular maintenance and proper ventilation can help mitigate these sources.