Effect of various factors on the rate of radon entry into two different types of houses.

Two detached houses situated on a hill, a slab-on-grade and a basement building, were used to assess factors that affect the rate of radon entry. For the former, the rate reached its maximum during a particular weather condition when the internal transport of radon was induced by the wind. The latter's rate was highest when the wind blew towards the hill. Changes in barometric pressure did not influence either. Rain affected the rate for the latter house. For the former house the adjusted rate of radon entry showed it to be higher in the morning. Diurnal variations were negligible for the latter house.