Do long-term average radon concentrations in schools and kindergartens differ from the average during working hours?

Radon concentrations in air in schools and kindergartens were measured by alpha scintillation cells, electret and etched track detectors, and a continuous device. Values obtained by different devices under different conditions are compared and their correlation discussed. The radon concentration averaged over working hours may differ substantially from the whole-day average, although Pearson's correlation coefficients between the two averages of 0.83 and 0.82 were obtained for schools and kindergartens, respectively.