Nanoparticles can enter the human body through several pathways:
1. Inhalation: Airborne nanoparticles can be inhaled and deposited in the respiratory tract, where they can penetrate deep into the lungs and even enter the bloodstream. 2. Ingestion: Nanoparticles present in food, water, or accidental hand-to-mouth transfer can be ingested and absorbed through the gastrointestinal tract. 3. Dermal Absorption: Nanoparticles in cosmetics, sunscreens, or other topical products can penetrate the skin barrier and enter systemic circulation.
