Outdoor radon-222 in Arctic Finland

Abstract

Outdoor radon-222 was measured at Sevettijärvi, northern Finland (69°35′N, 28°50′E) from September 1995 to January 2000. Radon-222 was measured via its beta emitting short-lived progeny collected on a glass-fibre filter. The data set from Sevettijärvi contains 25 641 hourly values of radon-222 activity concentration with a median value of 1.2 Bq m⁻³. Wind speed and direction, vertical mixing and source areas of air masses all have an effect on the radon-222 content of the air. The results show that, excluding very stable mixing conditions, most of the radon-222 is long-range transported. The radiation dose caused by outdoor radon-222 is only about one per cent of the total radiation dose for the Sevettijärvi residents.