Quality factors for alpha particles in the human respiratory tract.

Quality factors of alpha particles emitted by radon progeny in the human lung have been calculated by using the formula recommended by the International Commission on Radiological Protection. Calculations have been carried out for different combinations of sources, energies, and targets. The values obtained are between 20 and 26, with an average of about 24. These are comparable to previously published results for the human lung and for the general consideration of alpha particles emitted in tissue.