Determining the spatial scale of variation in soil radon concentration

摘要: Increasing concern about possible links between emissions of radon and certain types malignant disease has led to local regional surveys measure concentrations in the soil dwellings. The spatial scale at which varies is largely unknown, so efficient sampling schemes methods mapping cannot be selected. To determine variation English Midlands we measured using solid-state nuclear track detection three areas different geological complexity. In two them used an unbalanced multistage scheme with seven stages nesting: Hereford survey covered distances from 10 m 7.5 km, Buxton 1 3.75 km. results nested suggested that geology exerts a strong control on variation. Finally was every 20 along 2-km long transect crossed several lithologies close Nottingham. values changed erratic way transect. sample variogram substantial nugget variance, suggesting much occurred for less than interval. structure longer seems controlled by underlying geology. These have implications designing further selecting method mapping. Stratification based lithology might only feasible solution sampling, estimating over large areas. Where locally component large, estimation kriging, example, would confer little additional benefit compared classification.