Ultrafines vary in size from 0.1 micrometers down to 0.001 micrometers (or 100 nanometers down to 1 nanometer in diameter; a nanometer is a billionth of a meter). The largest of these particles has a diameter 1/1000th of the width of a human hair, and the smallest has a diameter 1/100,000th of a human hair. ... and the fall of drug …
