These fibers are 10 - 50 times thinner than the human hair. (essentiallymel.com)
Fine particulate pollution is a mixture of solid particles and liquid droplets, many times smaller than a human hair. (businessinsider.com)
They have illustrated their findings with the creation of nano «sieves» that can help separate molecules down to an unprecedented size 10,000 times finer than a human hair. (sciencedaily.com)