A mix of various pollutants are monitored at each site together with meteorological data:

Nitrogen Dioxide (NO2);
Sulphur Dioxide (SO2);
Ozone (O3);
PM10 Particulate concentration using Tapered Element Oscillating Mass Balance, (TEOM) technology and
Beta Attenuation (BAM) technology, Nephelometry, (local visual distance – LVD);
Wind Speed;
Wind Direction;
Ambient Temperature;
Solar radiation (Global & UVA).

Link to the EPA air quality data tables