Evaluation of Background Ionizing Radiation Level of Selected Oil Spill Communities of Delta State, Nigeria

Abstract

Study of the terrestrial Background Ionizing Radiation levels of selected Oil Spill Communities of Delta State, Nigeria have been carried out using Digilert 200 and Radalert 100 nuclear radiation monitor and a geographical positioning system (Garmin GPSMAP 76S). The exposure rates of the five communities ranges from 0.016 to 0.030  at Jones Creek, 0.014 to 0.034  at Opuwade Community, 0.015 to 0.037   at Okpare community, 0.007 to 0.029  at OtuJeremi community and 0.011to 0.040  at Otor-Edo community. The obtained mean exposures rates were higher than ICRP standard limit of 0.013. The absorbed dose rates calculated ranged from 139.2 to 261 (Jones Creek), 121.8 to 259.8 nGyh-1 (Opuwade Community), 130.5 to 321.9 nGyh-1 (Okpare community), 60.9 to 252.3 nGyh-1 (OtuJeremi community) and 95.9 to 348 nGyh-1 (Otor-Edo community). The estimated annual effective dose equivalent varies from  0.21 to 0.40 , 0.19 to  0.45 , 0.20 to  0.49 , 0.09 to 0.39  and  0.15 to 0.53  for Jones Creek, Opuwade Community, Okpare community, Otu Jeremi community and Otor-Edo community respectively while the excess lifetime cancer risk calculated for Jones Creek varies from (0.75  to 1.40)  x 10-3, Opuwade community (0.65 to 1.59 )×, Okpare community (0.70 to 1.73 ) x , OtuJeremi community (0.33 to 1.35)× and Otor-Edo community (0.51 to 1.87)×. All the mean values of absorbed dose, annual effective dose and excess lifetime cancer risk exceeded their recommended safe values. The results obtained in this work may not constitute any immediate health risk to the residents of the selected oil spill communities but long term exposure in the area may lead to detrimental health risks.