Alpha-and beta-activities per unit volume of air due to radon (222Rn),thoron (220Rn) and their decay products were measured in the air of various health centres situated in different districts of the city of Marrakech.Both CR-39 and LR-115 type Ⅱ solid state nuclear track detectors (SSNTDs) were used.The committed equivalent doses due to the 218Po and 214Po radon short-lived progeny were evaluated in different tissues of the respiratory tract of doctors,nurses and patients from the inhalation of air inside the studied health centres.Annual effective doses due to radon progeny from the inhalation of air by doctors,nurses and patients inside the studied health centres were evaluated.