Ultrafine particles

Top Cited Papers
Open Access
Publisher Website
Google Scholar
Abstract
Particles that are less than 100 nm in diameter are commonly defined as ultrafine. However, all particle populations that are found in the air are polydispersed—that is, they comprise particles with ranges of diameters that are usually summarised as mean or median diameter. There is no reason at the moment to think that there is much difference between a 90 nm and a 110 nm particle in ability to have an adverse effect and there is little evidence for the cut off point for the ultrafine effect. Ultrafine particles are very small compared with the cellular structures and so this may be important in the apparent problems they present to the lung (fig 1).