Assessment of the Natural Radioactivity and Concentrations of Some Heavy Elements in the Dust of Some Schools in Karbala, Iraq

Introduction: This study covered the assessment of the natural radioactivity levels and heavy metalsconcentration in dust samples collected from selected schools in the holy Governorate of Karbala. The purpose of thisstudy was to assess the radiological health and safety impact of dust pollution on the children going to school. Material and Methods: Sodium Iodide system (NaI [TI])from BICRON and the Atomic Absorption Spectrometer from SHIMADZU were used to measure the natural radioactivity in terms of ۲۳۸U, ۲۳۲Th, and ۴۰K, as well as the concentrations of some heavy metals in the dust samples. Results: The specific activity of ۲۳۸U, Th۲۳۲, and ۴۰K in dust samples were ۵.۵۹± ۰.۱۶۷۹ to ۷۱.۹۱±۱.۶۵۶۱ Bq/kg, ۱.۳۶±۰.۰۹۶۳ to ۴۳.۳۵±۱.۰۴۳۴ Bq/kg, ۶۶.۹۴±۱.۶۳۸ to ۴۱۷.۹۱±۱۳.۷۲۱ Bq/kg, respectively. The external and internal hazard indices were ۰.۰۴۷ ± ۰.۰۰۱ to ۰.۴۴۹±۰.۰۱۱ and ۰.۰۶۲±۰.۰۰۱۶۹ to ۰.۶۴۳±۰.۰۱۵۸۳   respectively. The absorbeddose rate and radium equivalent values ranged from ۸.۲۱±۰.۲۱۵ to ۷۶.۸۳±۱.۹۶۸nGy/h and ۱۷.۴۵±۰.۴۵۸to ۱۶۶.۰۸±۴.۲۰۵ Bq/kg, respectively. The concentration of lead was within the range of ۸.۸۳۹-۲.۶۸۹ mg kg-۱ and the concentration of Cd ranged from ۰.۱۴۱ mg kg-۱ to less than the lower limit of detection of the Atomic Absorption Spectrometer. Conclusion: The absorbed dose rate, effective dose (indoor and outdoor), hazard indices, and radium equivalent values were within the range of values indicated in the UNSCEAR ۲۰۰۸ report. The levels of lead and cadmium concentration detected in some schools were due to dust pollution in the Schools environment.

Keywords:

Specific activity , Hazard Indices , Effective Dose , Air pollution