Radon, progeny and health: investigation in different environments in Northamptonshire

The essential findings of this study are that, from a known radium source, radon variability in the environment of the buildings studied is an inevitable consequence of the variability of the prevailing surface boundary layer atmospheric conditions. These influences will be modified by the structural characteristics of the building and will vary directly, relative to the mechanically created variation of the atmospheric conditions inside the building. From the findings, a general hypothesis is postulated. It is probable, that the diurnal variation of radon results from the diurnal variation in ambient water vapour pressure. And that the seasonal variation in radon, arises from the changes in the range of this diurnal variation during the course of a year brought about by changing levels of temperature and barometric pressure. This will be varied to the extent, that wind pressure affects directly both the radon path from source to the building and the level of water vapour pressure. Where mechanically induced air-movement in the building creates overriding pressure and air exchange, then this is likely to determine the pattern of variability; and as a result can be used under some circumstances as a mitigation agent; with levels of concentration anticipated in a predictable way. The current practice of reliance on average radon values derived from time-average radon values of a living room and a bedroom, as being representative of the alpha particle dose delivered to an individual, may well significantly overstate the dose actually delivered to that individual at a particular radon level measured. This would follow potentially from a preponderance of radon transported overnight requiring a lower weighting factor for the amount delivered to above-ground-floor sleepers, and the much reduced level of intake to the respiratory system from reduced breathing rate during the sleep mode. Potentially also, from the mechanism postulated which implies the limitation of the impact of alpha particles, related to an association between water vapour pressure, radon and particulates in the atmosphere. Linkage between elevated radon levels and surface geological was identified; but no positive connection was apparent linking respiratory system cancers relative to radon/geology