The total population dose due to indoor radon and thoron
exposure, with the assumption ofACH¼0.5, is found to be 0.42
mSvforthelowesthumidity(AH¼1.35 g cm
3
)upto0.97mSvfor
the highest humidity (AH20 g cm
3
) for granite while the corresponding values are 0.21 and 0.53 mSv for brick. These results show
that effective dose can change by the factor 2 due to humidity.
Further investigations will be necessary tofind relations between
radon and thoron exhalation to other environmental parameters, e.g.,
temperature and pressure as well as their gradients