A study on the thoron sensitivity of radon detectors available to Canadians.

Radon and its decay products have been identified as the second leading cause of lung cancer after tobacco smoking. Thoron is an isotope of radon. With increased awareness of radon, questions related to thoron are arising from the public. Currently, only radon detectors are commonly available to Canadian homeowners. A study on the thoron sensitivities of those radon detectors was undertaken. The average thoron sensitivity relative to radon varied from a factor of 0.012 to 0.74 for the five commonly available types of alpha track radon detectors. The potential impact of thoron sensitivity on radon test results is discussed.