SEASONAL CORRECTION FACTORS FOR INDOOR RADON MEASUREMENTS IN THE UNITED-KINGDOM

Indoor radon concentrations are subject to seasonal variation and, in order to reflect annual averages, measurements made over periods other than twelve months need to be adjusted accordingly. A series of measu rements made in the radon affected area of southwest England as part o f an epidemiological study have been used to estimate seasonal correct ion factors. These are found to be substantial, and result in a change in the estimated annual average of up to 35% for measurements taken o ver a six month period, and 56% for measurements taken over a three mo nth period. The results agree closely with previously published correc tion factors based on measurements made throughout the UK in an earlie r time period. This confirms the stability of such correction factors over time, and the applicability of general UK correction factors to m easurements of indoor radon in the radon affected area of southwest En gland.