Estimation of Annual Effective Dose Equivalent and Excess Life Cancer Risk Across Major Markets in Northern Cross River State Nigeria

Human exposure to ionizing radiation from natural and artificial sources is an unpreventable phenomenon on Earth. Radiation profile and dose rate for some markets in northern Cross River State, Nigeria have been ascertained using a 451p ion chamber survey meter, and the following parameters of radiation were calculated, absorb dose, annual effective dose equivalent, and excess life cancer risk. The dose rates measured within five major markets are as follows; Obanliku, 0.07μsv/h to 0.18μsv/h, Obudu, 0.03μsv/h to 0.17μsv/h, Bekwara, 0.06μsv/h to 0.78μsv/h Ogoja, market 0.05μsv/h to 0.15μsv/h, Okuku, 0.06 μsv/h to 0.25 μsv/h, The mean value for the dose rate was 0.122 ± 0.031 for Obanliku, 0.120 ± 0.031 for Obudu, 0.164 ± 0.159 for Bekwara, 0.097 ± 0.030 for Ogoja, 0.117 ± 0.043 μsv/h for okuku, Mean values of 0.194 ± 0.072msvy-1 , 0.184 ± 0.045msv/y, 0.250 ± 0.244msv/y, 0.147 ± 0.047msv/y, and 0.179 ± 0.067msv/y, for AEDE were observed respectively for Obanliku, obudu, bekwara, ogoja, and okuku within the markets. Similarly, 0.622 ± 0.238 x 10-3 , 0.643 ± 0.158 x 10-3 , 0.876 ± 0.853 x 10-3 , 0.514 ± 0.167 x 10-3 ,and 0.628 ± 0.233 x 10-3 , were recorded for ELCR, within the markets. The AEDE values are within the permissible limit as recommended by the international bodies, the ELCR values are also within the permissible limit. The AEDE & ELCR values imply that the market sides are radiation safe for any radiological health burdens that might arise due to absorbing doses from background ionizing radiation, but the probability of occupants developing cancer over a lifetime exposure in marketplaces is high. It is recommended that periodic background ionizing radiation monitoring and evaluation, and radioactive concentration of nuclides in soil and rocks of the are been carried out by local authority.