One row is one city's monthly mean of fine (PM2.5) and coarse (PM10) particles in micrograms per cubic meter, January 2018 to December 2023, with the main source the city names. 718 rows.
Planted faults: three stations write their dates in other formats, one station has three months missing, PM2.5 is blank five times and "n/a" once, PM10 says "High" twice, one reading is repeated, and in 2023 one city name and one source label are written another way.
Part of the Verdant Union datasets, invented teaching data about a fictional union of five countries (Arvenia, Brisland, Coralis, Dovrena, Estmark) built to behave like real environmental statistics. Source: LucidPlexus, dataset page https://lucidplexus.com/community/dataset.php?slug=greenery