Measurement of radon accumulation in living houses around Bukuru mining site and Kaduna Metropolis

Radon accumulation in fifty living houses around mining site in Jos Plateau and twenty living houses in Kaduna Metropolis was carried out using pro-series 3 radon gas detector, acquired from United State of America. The measurement was carried out both in the wet and dry season. Pro-series 3 gas detector was calibrated in a newly constructed radon gas calibration chamber using aluminum sheet of thickness 0.002m and measuring 0.5m x 0.5m x 0.6m. The chamber is lagged with cotton wool of thickness 10.00cm and completely air tight with interior volume of 0.150m3. The accumulation of radon in the calibration chamber at 290C, 350C, 400C, 450C and 520C was carried out using radium standard source. Calibration/emanation fraction of radon was determined within the time interval of 400hours. It ranges from 0.00097 at 250C to 0.694 at 50 0C; radon accumulation in 0.150m3 of a closed chamber over temperature and time, shows a linear growth of 2000Bq to 8000Bq within temperature interval of 300C and 500C.The radon accumulation ranges from 1.28 Bqm-3 to 619.67 Bqm-3 .The arithmetic and geometrical mean were 155.37 Bqm-3 and 97.14 Bqm-3 respectively. The radon accumulation during the wet season ranges from 5.83Bqm-3 to 248.39 Bqm-3. The arithmetic mean and geometric mean were found to be 62.81 Bqm-3 and 44.49Bqm-3 respectively. Variation of the radon accumulation obtained during wet and dry season for all sample points was found to have a factor range of 1.8 to 2.7. Measurements within Kaduna Metropolis revealed that the least measured value was 0.61 Bqm-3 recorded at Barnawa, while the highest value of 77.8 Bqm-3 was received at Angwan Dosa and Malali. Arithmetic and geometric mean were found to be 34.92Bqm-3 and 18.36 Bqm-3 respectively.