The air quality index is calculated solely on the basis of 1-hour unverified data from air monitoring stations for the following substances: NO2, SO2, PM10, PM2.5, O3, benzene (C6H6) and carbon monoxide (CO). The value of the air quality index is calculated from below table for the 6 index classes (1 hour average), where individual indices are calculated for each pollutant by comparing the measured pollutant with the specified threshold values. Then the general index takes the value of the worst individual index for the pollutant. Individual classes are in line with the Polish air quality index published on the website of the Main Inspectorate for Environmental Protection http://powietrze.gios.gov.pl/pjp/current , whereas colouring and the naming is slightly different and remains in the hues and presents the air quality index in the form of ATMOLUDEK, which is well-known society in the Pomeranian region and have been published on www.armaag.gda.pl and http://airpomerania.pl for more than 10 years. In the case of individual indices in the absence of sufficient measurement information for the index calculation, the station is displayed as a gray ATMOLUDEK which means no data.

Classes of air quality index	PM10 [µg/m3]	PM2,5 [µg/m3]	O3 [µg/m3]	NO2 [µg/m3]	SO2 [µg/m3]	C6H6 [µg/m3]	CO [mg/m3]
Very Good (1)	0-20	0-13	0-30	0-40	0-50	0-5	0-2
Good (2)	20,1-50	13,1-35	31-70	41-100	51-100	6-10	3-6
Satisfactory (3)	50,1-80	35,1-55	71-120	101-150	101-200	11-15	7-10
Sufficient (4)	80,1-110	55,1-75	121-160	151-200	201-350	16-20	11-14
Bad (5)	110,1-150	75,1-110	161-240	201-400	351-500	21-50	15-20
Very bad (6)	>150	>110	>240	>400	>500	>50	>20