Gamma Radiation in Swedish Dwellings

Abstract

A nation-wide investigation has been made of gamma radiation in Swedish dwellings. The measurements were made with thermoluminescence dosemeters, sent to the selected participants by mail. 1300 dwellings were included. In each dwelling three measurements were made: in the kitchen, in the living-room and in the main bedroom. The mean annual absorbed dose to the gonads from gamma radiation in dwellings in Sweden was found to be 0.65 mGy (corresponding to an absorbed dose rate in air of 110 nGy.h-1), cosmic radiation excluded. The calculated annual collective effective dose equivalent to the population of Sweden was about 4000 man.Sv. The mean gamma radiation level in dwellings in multi-family houses was found to be almost twice as high as the mean level in detached houses. Significant differences were also found between dwellings built of different building materials, dwellings situated in different parts of the country, and dwellings built during different periods. Comparisons are made with the investigation conducted by Hultqvist in 1953-1956 and with the indoor gamma radiation levels of several other European countries where large-scale surveys have been performed.