Geochemical compositions of surface to shallow soil samples of Manyoni uranium deposit　in Tanzania were determined by X-ray fluorescence analysis (XRF). Uranium, calcium and chlorine are abundant at the depth of 40 cm to 140 cm. Strong correlations between U, CaO and chlorine suggest uranium and carbonates deposition in a Salt Lake system. Strontium content is higher (370 to 480 ppm) than the average upper continental crust UCC (320 ppm) at the depth of 60 cm to 120 cm suggesting Sr accumulation in carbonates. TiO2 and Fe2O3 abundances appear along the profile but have normal concentrations below the average UCC content. Vanadium is positively correlated to Fe2O3 and Ni (mafic sources) concentrations and negatively correlated to U. Uranium precipitation is suggestive of abrupt evaporation during dry season at Manyoni depositional basin. Chlorine (Cl) with high concentration in the vertical profile may be yielded in the sediments after evaporation of the lake water.

Occupational radiation doses in diagnostic radiography Centres of the Lake Zone Regions of Tanzania were measured and analyzed. Thermoluminiscent Dosimeters (TLDs) were distributed to 17 radiation workers from 8 selected medical centres over a period of three (3) months. The estimated ambient doses in the Centers was measured by using a calibrated survey meter RAM DA-3-2000 of TAEC under SSDL Laboratory. The individual dose recorded ranged from 0.09 to 1.12 mSv which were all below the ICRP limit of 5mSv for 3 months. The radiation dose (ambient) recorded at 1 m from the control lead glass window ranged from 2.15 µSv/h to 7.27 µSv/h. The ambient doses were compared to the limit of 7.5 µSv/h set by ICRP. Higher values of ambient doses and indivudual doses were observed in some centres which entails improper radiation safety and protection measures in radiation cantres. But with the use  of protective gears, radiation workers receive lower doses hence abide with ALARA principle.