Table 2. Seasonal variations of radon, thoron, progeny concentrations, unattached fractions and quilibrium factors in 42 houses of Garhwal Himalaya.

	Rainy Season				Winter Season				Summer Season				Annual Mean
	Min	Max	AM ± SD	GM	Min	Max	AM ± SD	GM	Min	Max	AM ± SD	GM	Min	Max	AM ± SD	GM
Radon Concentration in Bq/m3	11 ± 2	120 ± 7	49 ± 28	42	36 ± 4	182 ± 9	71 ± 32	66	5 ± 1	174 ± 8.7	43 ± 34	34	27	148	54 ± 24	51
EERC (Attached + Unattached) in Bq/m3	4.0 ± 0.6	52.2 ± 2.2	16.3 ± 12.1	13.2	6.7 ± 1	65.1 ± 2.5	25.9 ± 14.2	22.6	2.1 ± 0.4	37.6 ± 1.9	15.9 ± 9.7	13.0	7.6	48.6	19.5 ± 8.5	17.9
EERC (Attached) in Bq/m3	3.8 ± 0.9	48.8 ± 3.2	15.1 ± 10.3	12.5	5.7 ± 1.1	47.5 ± 3.4	19.2 ± 10	16.7	1.4 ± 0.5	34 ± 2.7	13.6 ± 8.2	11.1	7.0	33.3	16.7 ± 6.3	15.5
EERC (Unattached) in Bq/m3	0.1	15.9	1.2 ± 3.1	0.44	0.2	27.8	6.7 ± 10.7	2.6	0.26	13.0	2.3 ± 2.9	1.3	0.4	17.7	2.8 ± 3.3	1.8
Unattached Fraction (222Rn Progeny)	0.01	0.35	0.05 ± 0.06	0.03	0.01	0.84	0.21 ± 0.23	0.11	0.01	0.87	0.16 ± 0.15	0.11	0.02	0.37	0.12 ± 0.07	0.10
F factor for Radon & Progeny	0.10	0.90	0.39 ± 0.23	0.31	0.10	0.91	0.39 ± 0.19	0.34	0.10	0.83	0.41 ± 0.18	0.37	0.10	0.62	0.4 ± 0.13	0.37
Thoron Concentration in Bq/m3	3 ± 1	125 ± 8	30 ± 28	22	2 ± 1	210 ± 10	53 ± 52	33	4 ± 1	195 ± 10	47 ± 53	27	5	174	43 ± 37	32
EETC (Attached + Unattached) in Bq/m3	0.4 ± 0.1	5.5 ± 0.2	1.9 ± 1.2	1.6	0.3 ± 0.1	4.8 ± 0.2	1.9 ± 1.1	1.6	0.3 ± 0.1	11.2 ± 0.3	1.8 ± 1.9	1.2	0.6	4.6	1.9 ± 1	1.6
EETC (Attached) in Bq/m3	0.2 ± 0.1	3.7 ± 0.3	1.4 ± 0.7	1.2	0.3 ± 0.1	4.7 ± 0.3	1.6 ± 0.9	1.4	0.2 ± 0.1	9.6 ± 0.5	1.3 ± 1.6	0.9	0.5	4.1	1.5 ± 0.7	1.3
EETC (Unattached) in Bq/m3	BDL	1.8	0.5 ± 0.8	0.2	BDL	1.8	0.3 ± 0.5	0.1	0.1	1.8	0.5 ± 0.5	0.3	BDL	1.5	0.4 ± 0.3	0.3
Unattached Fraction (220Rn Progeny)	0.01	0.66	0.21 ± 0.20	0.11	0.01	0.46	0.10 ± 0.10	0.07	0.01	0.70	0.27 ± 0.16	0.21	0.05	0.38	0.19 ± 0.09	0.17
F factor for Thoron & Progeny	0.02	0.36	0.09 ± 0.06	0.07	0.01	0.21	0.06 ± 0.05	0.05	0.01	0.31	0.06 ± 0.05	0.05	0.02	0.17	0.07 ± 0.04	0.06