INDUSTRIAL RADIATION MONITORING AROUND KADUNA METROPOLIS

Abstract

Apart from the amount of radiation, which may be encountered due to radioactive substances, individuals are also exposed to radiation because of the nature of the environment. This natural source of exposure is often referred to as background radiation and studies have revealed two main components, viz: radioactivity in the earth crust and extraterrestrial radiation called cosmic rays. The amount either of these radiation sources contributes varies with locations. To examine this, both LiF: Ti and CaSO₄: Mn phosphor chips were investigated and the CaSO₄ dosimeter chosen because of annealing and contamination problems associated with LiF. The CaSO₄ TLD was calibrated using 90Sr beta source as standard. A low level standard deviation of 4% was recorded around 25mR region. It was established that among the sampled areas, the NNPC and Panteka recorded high radiation levels. Measurements of photoemission produced around these industrial areas of Kaduna were also determined and compared with standards. Results established that apart from NNPC and Panteka, other locations were uncontaminated. However, locations below ground level at various depths around metallic waste dumps of Panteka and NNPC recorded large exposure rate, which increased with depth until a plateau is attained.