Temperature variation of indoor and outdoor radon progeny

The indoor and outdoor radon progeny concentrations were investigated at a semi-hilly area of Pathankot in Punjab using the method of beta particle counting of aerosol samples collected on a glass micro-fiber filter. A linear relation was found between indoor and outdoor equilibrium equivalent concentrations of radon-222 (EECRn) with correlation coefficient of R=0.9. The indoor and outdoor EECRn levels were also studied as a function of outdoor temperature. The variations with temperature in both cases showed negative correlation with correlation coefficient of R=-0.66 and R=-0.73, respectively. The ratio of outdoor to indoor EECRn investigated as a function of absolute difference of indoor and outdoor temperatures (Tin–Tout) resulted in a correlation coefficient of R=0.52, which is positive. The indoor EECRn was also estimated from an empirical relation based on transport of inside and outside radon progeny through ventilation. The measured inside EECRn agrees well with the computed value.