Pathological effects of nano-sized particles on the respiratory system

Recent advances in nanotechnology have made significant progress in biomedical sciences. However, there are growing concerns that exposure to naturally-occurring and synthetic nano-sized particles promotes various types of human diseases. The lungs are the vital organ for gas exchange. Due to their unique position, the lungs can be the primary route that nanoparticles (NPs) enter the human body, which exerts toxic effects. In spite of the wide applications of NPs, the precise effects on health following exposure are not fully understood. To address this, the biophysical properties of naturally-occurring and synthetic NPs, their pathological effects on the respiratory system and the potential human health risk are examined. The goal of this review is to provide the current evidence that exposure to NPs is a risk factor to develop human diseases. The understanding of the pathological process by NPs is essential in preventing and the treatment of nanoparticle-induced human diseases.