Fine particles measure 2.5 microns or less in size (approximately 1 /
30th the diameter of a human hair) and can penetrate deep into the body's respiratory system.
Not exact matches
This type
of pollution refers to particles found in the air that are less than 2.5 micrometers in
diameter, or 1 /
30th the average width
of a
human hair.
Ultrafine dust particles refers to dust which is about 2.5 micrometers in
diameter, nearly a
30th the thickness
of human hair.
The link between fine particles, the
diameter of which is smaller than a
30th of a
human hair, and cardiopulmonary disease has been established for two decades, and the E.P.A. has regulated such emissions since 1997.