Indoor radon-daughter concentration and gamma radiation in urban and rural homes on geologically varying ground.
The radon (Rn)-daughter level (track film, 3 months) was lower in 129 urban than in 197 rural houses (geometric means, (GM) 18 versus 40 Bq/m3; P < 0.001; range 3-416). In rural dwellings higher levels were found in those built over deposits of alum shale occurrences (P = 0.04; 12 on porous glaciofluvial cover 94 Bq/m3; 127 others 43 Bq/m3; significant interaction, P = 0.01), than in 158 others (37 Bq/m3). There was no systematic effect of the type of water supply, neither of indoor smoking. One hundred twenty three homes with a complete cellar were lower than 200 with no or part cellar (18 versus 40 Bq/m3; P < 0.001). There was only a weak association between log-transformed gamma radiation (GM 10, range 33-50 microR/h) and Rn-daughter levels (r = 0.18; 95% confidence interval 0.07-0.28). Our results show the importance for indoor Rn-daughter levels of the bedrock and cover beneath the house, and the need for Rn-daughter measurements in epidemiological studies.
Tell
I
I
Department of Occupational and Environmental Medicine, University Hospital, Lund, Sweden.
Jönsson
G
G
Bensryd
I
I
Attewell
R
R
Skerfving
S
S
Strömberg
U
U
D016902:Air Pollution, Indoor / Q000032:analysis*; D003252:Construction Materials / Q000032:analysis; D006798:Housing / Q000592:standards; D006801:Humans; D011839:Radiation, Ionizing; D011886:Radon / Q000032:analysis*; D012423:Rural Health; D012907:Smoking / Q000453:epidemiology; D012987:Soil / Q000032:analysis*; D013548:Sweden / Q000453:epidemiology; D014504:Urban Health
D012987:Soil; D011886:Radon