GEOSTATISTICALLY CONTROLLED FIELD-STUDY OF RADON LEVELS AND THE ANALYSIS OF THEIR SPATIAL VARIATION

Increasing concern about possible links between radon concentration and certain types of malignant disease has led to local, regional and national surveys being conducted to determine radon levels in soil and indoors. The nature and scale of the spatial variation of radon exhalation in the natural environment are, however, largely unknown. We have applied multistage sampling and a nested analysis of covariance to determine how radon emission varies spatially in the soil. By surveying three areas of increasing geological complexity in the English Midlands, ranging from one principal lithology to several, it has been shown that soil radon values vary in a very erratic way over distances of a few metres. Nevertheless, geostatistical analyses have shown that the longer scale of variation in soil radon is determined by underlying geology.