ENVIRONMENTAL GAMMA-DOSE MEASUREMENTS IN MEXICO-CITY USING TLD

The aim of this work is to measure the gamma dose component of environ mental radiation in Mexico City's metropolitan area. To perform the TL dosimetry, CaF2:Dy, CaF2:Mn, alpha-Al(2)0(3):C and LiF:Mg, Cu, P crys tals were used. The values of environmental gamma dose rate measured r anged between 83 and 112 nGy h(-1) for the time interval going from Ja nuary to August 1994. Outdoor dose rates were 85 nGy h(-1) +/- 2% for city sites having soil of either volcanic or lacunar origin; this rate was 107 nGy h(-1) +/- 2% at a nearby hill belonging to a volcanic cha in. Indoor rates were about 20% higher than outdoor ones at the same l ocation.