Sentences with phrase «30th of a 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.
https://www.treehugger.com/ 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.
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.
Ultrafine dust particles refers to dust which is about 2.5 micrometers in diameter, nearly a 30th the thickness of human hair.