Lifetime Attributable Cancer Risk from Terrestrial Gamma Radiation near Oil Wells in Rukpokwu and Aluu Communities, Nigeria
ORLUNTA, ALOYSIUS, NDUBISI *
Department of Science Laboratory Technology, School of Science Laboratory Technology, Port Harcourt Polytechnic, Rumuola, Port Harcourt, Rivers State, Nigeria.
ESEOSA, MELODY AGBONIFO
Department of Science Laboratory Technology, School of Science Laboratory Technology, Port Harcourt Polytechnic, Rumuola, Port Harcourt, Rivers State, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
The Excess lifetime cancer risk has been computed from background ionizing radiation in Rukpokwu and Aluu communities using the GQ Nuclear radiation Detector (Gmc-300E plus). The geographical positioning system (GPS) was used to record the geographical coordinates of the measured sample points. The Excess Lifetime Cancer Risk (ELCR) describes the potential carcinogenic effects of ionizing radiation on humans. The measured Background ionizing radiation in Rukpokwu varied from 0.009 mR/hr-0.013 mR/hr with an overall average of 0.0107±0.0014 mR/hr while that of Aluu community ranged from 0.007mR/hr-0.013mR/hr with an overall mean of 0.0107±0.0062 mR/hr. The computed annual absorbed dose ranged from 75.4nGy/hr-113.1nGy/hr with an overall average of 91.64±3.69 nGy/hr for Rukpokwu town, while the absorbed dose for Aluu town varied from 58.0 nG/hr-116.0 nG/hr with an overall average of 92.51±4.90 nG/hr. Also, the annual effective dose rate (AEDR) calculated for Rukpokwu community varied from 0.12mSv/yr-0.17mSv/yr with an overall average of 0.140±0.06mSv/yr. While, the annual effective dose rate (AEDR) calculated for Aluu town ranged from 0.09mSv/yr-0.18 mSv/yr with an overall mean of 0.142±0.08mSv/yr. The excess lifetime cancer risk computed for Rukpokwu town ranged from 0.40×10-3-0.61×10-3 with an overall average of (0.19±0.062) ×10-3. Also, the calculated excess lifetime cancer risk for Aluu community varied from 0.42×10-3 -0.62×10-3 with an overall average of (0.40±0.03) ×10-3. The measured background ionizing radiation for both Rukpokwu and Aluu communities are all lower than the safe limit of 0.013 mR/hr by the International Commission on Radiological Protection (ICRP, 2000). These values indicate that the people within these locations may not be in danger of any health hazard arising from the exposure to background ionizing radiation Although, the computed values of the absorbed dose, annual effective dose rate, and the excess lifetime cancer risk are all slightly above the safe limits of 59.0 nGy/hr, 1.0 mSv/yr and 0.29×10-3 respectively by the International Commission on radiological Protection (ICRP, 2000). However, there is presently no reported cases of health hazards arising from exposure to background ionizing radiation from the two communities. But a routine monitoring of the sample areas is required.
Keywords: Background Ionizing Radiation (BIR), excess lifetime cancer risk, annual effective dose rate, International Commission on Radiological Protection (ICRP)