Evaluation of Lifetime Cancer Risk in Some Vegetables and Soil Samples in Two Main Cities in Ogun State: Human and Ecological Risk

The spate of health challenges via the ingestion of radionuclides is still of concern especially in regions that have no clear documentation 14 of background of radioactive sources. The present study evaluated the activity concentrations of naturally occurring radioactive nuclides 15 in plants and their corresponding soil collected at Ibeshe and Covenant University community areas of Ogun State, Nigeria. The activity 16 concentrations and other radiological risks from consuming the leafy vegetables were also estimated. The results show that the mean 17 concentration of 226Ra, 232Th, 40K in the agricultural soil were found to be 24.18±2.31, 20.93±2.27, 20.95±1.9 for Ibeshe and 58.76±4.84, 18 26.06±1.93, 33.87±2.23, respectively for Covenant University. Whereas, for the leafy vegetables, the mean concentration of 226Ra, 232Th, 19 40K were found to be 5.02±0.9, 7.98±1.70, 427.82±29.75 for Ibeshe and 17.57±2.35, 22.19±3.0, and 424.17±25.15 for Covenant 20 University Community. In comparison, all these values are within the recommended limits of 32.00 and 45.00, 420.00, Bqkg-1for 226Ra, 21 232Th, 40K according to the United Nations Scientific Committee on the Effect of Atomic Radiation (UNCEAR) except the mean value 2 for Covenant University soil for 232Th which is slightly higher. The values obtained were comparable 22 to the internationally recommended 23 values. The mean value for excess lifetime cancer risk (ELCR) for Ibeshe North is 31.08, while that of Canaanland (CU) is 239.03, 24 respectively is lower than the recommended limits of other published papers 1.72 x 104 according to International Commission on 25 Radiological Protection (ICRP). These lower radiological risks indicate apparently that the chemical carcinogenic pollutants in the 26 samples may be the major risk, inducing chemical parameters in the study area. This study will serve as a baseline data for any 27 radiologically induced diseases. Significantly, it will serve as a baseline data for any radiologically induced diseases from vegetables in 28 Nigeria and suggests further research on chemical toxicity risks on the same samples