Table 1.

Overview of correction factors: 4 monthly groups (a) and 3 quarterly groups (b) Authors’ own work based on Fijałkowska-Lichwa and Przylibski (4)

Time of exposure	k1ma—for naturally ventilated facilities well insulated from the atmosphere	k1mb—for non-insulated facilities	k1mc—averaged for underground facilities	k1md—for facilities with mechanical ventilation system
Month (a)
January	3.34	1.41	1.52	0.73
February	2.80	1.38	1.42	0.38
March	1.56	1.19	1.16	0.52
April	0.55	0.96	0.88	0.40
May	0.83	0.77	0.74	0.40
June	0.60	0.71	0.70	0.73
July	0.70	0.71	0.81	1.76
August	0.56	0.69	0.78	1.80
September	0.63	0.83	0.95	2.40
October	1.40	1.00	1.10	1.20
November	1.20	1.30	1.30	1.60
December	2.70	1.50	1.60	1.60
Quarter (b)	k3ma—for naturally ventilated facilities	k3mb—for facilities with a mechanical ventilation system	k3mc—averaged for all underground facilities
No. 1	0.62	1.40	1.32
No. 2	0.76	0.81	0.90
No. 3	2.14	0.72	0.87
No. 4	1.96	1.31	1.37