in atmospheric chemistry
Small, dry, solid particles projected into the air by natural forces, such as wind, volcanic eruption and by mechanical or man-made processes such as crushing, grinding, milling, drilling, demolition, shoveling, conveying, screening, bagging and sweeping. Dust particles are usually in the size range from about \(1{-}100\ \unicode[Times]{x3BC}\text{m}\) in diameter and they settle slowly under the influence of gravity.
PAC, 1990, 62, 2167. (Glossary of atmospheric chemistry terms (Recommendations 1990)) on page 2185 [Terms] [Paper]