Yes, scented candles and air fresheners can negatively affect indoor air quality. They often release volatile organic compounds (VOCs) and other harmful chemicals into the air, which can cause respiratory issues, allergies, and other health problems. Burning candles also produces soot and particulate matter, further degrading air quality. To maintain a healthier indoor environment, consider using natural alternatives such as essential oils or houseplants for fragrance. Always ensure proper ventilation when using any scented products.