maximum average daily concentration of an atmospheric pollutant

synonym: peak daily average concentration of an air pollutant
https://doi.org/10.1351/goldbook.15868
Highest of the average daily concentrations recorded at a definite point of measurement during a certain period of observation.
Source:
PAC, 2007, 79, 1153. (Glossary of terms used in toxicology, 2nd edition (IUPAC Recommendations 2007)) on page 1255 [Terms] [Paper]