Nano particles

• Coarse particles


  Also called PM10s or dust, have a diameter between 1 x 10^-5 m and 2.5 x 10^-6 m, contain many thousands of atoms
• Fine particles


  Also called PM2.5, have a diameter between 1 x 10^-7 m and 2.5 x 10^-6 m, contain several thousand atoms
• Nanoparticles


  Have a diameter between 1 and 100 nanometers, only contain a few hundred atoms
• As particle size decreases by 10 times, the surface area to volume ratio increases by 10 times
• Nanoparticles can potentially be absorbed into the body and enter cells, but the long-term effects are unknown
• Nanoparticles have a huge surface area to volume ratio, so a smaller quantity is needed compared to normal particle sizes, e.g. for catalysts