Region	Country	Radon Bq/m³		Reference
Region	Country	Mean	Max.	Reference
West Asia	Aljouf, Saudi Arabia	10	31	This work
	Syria	44	520	[30]
	Kuwait	14	120	[31]
	Iran	82	3070	[32]
Africa	Algeria	30	140	[33]
	Egypt	9	24	[34]
America	Canada	34	1750	[35]
	United State	46	1750	[36]
	Argentina	37	211	[37]
	Chile	25	86	[38]
East Asia	China	24	380	[39]
	Hong Kong	41	140	[40]
	India	57	210	[41]
	Japan	10	310	[42]
North Europe	Estonia	120	1390	[43]
	Finland	120	20,000	[44]
	Sweden	108	85,000	[45]
West Europe	Austria	48	190	[1]
	Switzerland	70	10,000	[3]
	United kingdom	20	10,000	[46]
South Europe	Cyprus	7	78	[47]
	Italy	75	1040	[48]
	Portugal	62	2700	[49]
Eastern Europe	Czech Republic	140	20,000	[50]
	Hungary	107	1990	[51]
	Poland	41	432	[52]
Oceania	Australia	11	420	[53]
	New Zealand	20	90	[54]
Median		46	480	[5]