in atmospheric chemistry
Airborne solid particles in the atmosphere which are of natural or manmade origin and which remain in @[email protected] for some time; in the United Kingdom the size of the grit particles is defined as greater than \(75\ \unicode[Times]{x3BC}\text{m}\) in diameter (retained on a 200 mesh British Standard sieve).
PAC, 1990, 62, 2167. (Glossary of atmospheric chemistry terms (Recommendations 1990)) on page 2193 [Terms] [Paper]