Surveying of Radioactivity Concentration of U-238, Th-232 and K- 40 and Evaluation of Radiological Health Parameters on Nigeria Coastal Line

Abstract

Activities around the Atlantic Ocean coastline region have greatly increased of resent due to industrial and commercial establishments. This study quantified the natural radionuclide contents in the waters along the Atlantic Ocean in West Africa, with special interest in the Nigerian coastline region. The study then evaluated the health risks associated with these natural radionuclides for each population living along the coastline. Several water samples were collected offshore and onshore from five different locations from south-west to south-south in clean plastic bottles and kept in the laboratory for 30 days. In preparation for the use of the HPG detector used, which is of serial number 9744, model GC8023 has a relative efficiency of 80% and a resolution of 2.3 keV full width at half maximum (FWHM) at 1.33 MeV. The results show variation in concentration levels in U238, Th232, and K40 across the coastline. The absorbed dose increases from the south-west down to the south-south of the coastline, ranging from 14.73 and 28.78 nGyhr-1 in the south-west, while in the south-south it is 18.75 and 26.18 nGyhr-1 . The indoor effective dose is in the range 0.072 to 0.141 mSv/y and the outdoor effective dose ranges from 0.018 - 0.035 mSv/y. The increase in absorbed dose is due to K-40 from the agricultural activities in the region and also the crude oil exploration use of radionuclides in oil fields. The excess lifetime cancer risk within the region is slightly comparable to the tolerable values set by regulatory bodies.