Particulate Matter at 2.5um or Less Measurement

**Semantic type:** Qualitative Concept

**Definition:** The total number of particles or droplets per unit volume in the air that are 2.5 microns or less in width.

**Synonyms:** - PM2.5 - PM2.5 - Particulate Matter 2.5 - Particulate Matter 2.5 - Particulate Matter 2.5