210Pb in home dust as a possible marker for radon exposure in indoor air.

Exposure to indoor radon is of great concern because it is an environmental hazard for developing lung cancer. 210Pb, a radon decay product, was measured in home dust samples from the city of Ottawa, Canada. The 210Pb level in dust ranged from 33 to 352 Bq kg(-1), with the geometric mean and median values of 105 and 110 Bq kg(-1), respectively. Despite the complexity of the formation of 210Pb in the indoor environment, an encouraging correlation between 210Pb concentrations in home dust and radon levels in indoor air was observed when the measurement data were grouped according to four geographic regions of the city. This observation could lead to the development of 210Pb in home dust as a potential marker for indoor radon exposure.