Nanoparticles can have negative health effects because they can enter the body through the skin, lungs, or intestinal tract and can cause harmful biological reactions. Some of the health effects of nanoparticles include: Inflammation: Nanoparticles can cause inflammation in the lungs and other organs. Cell damage: Nanoparticles can cause permanent cell damage through organ injury and oxidative stress. Respiratory and cardiovascular diseases: Nanoparticles can cause respiratory and cardiovascular diseases. DNA damage: Nanoparticles can cause DNA damage. Diseases: Nanoparticles can cause diseases like Parkinson's, Alzheimer's, asthma, cancer, emphysema, bronchitis, arrhythmia, dermatitis, vasculitis, urticaria, Crohn's disease, hypertension, and thrombosis. Nanoparticles can be a marker of air pollution and can be suspended in the atmosphere for a long time. They can be inhaled through active and passive smoking, or through household and occupational exposure.