Measurement of Background Ionizing Radiation Exposure Levels in Selected Farms in Communities of Ishielu LGA, Ebonyi State, Nigeria

The perceived implication of increase background radiation levels of farm lands due to inputs of fertilizers and agrochemicals has suggested the need to investigate the background ionization radiation (BIR) levels and associated radiation health parameters in farmlands located in communities of Ishielu LGA of Ebonyi State, Nigeria. An in-situ method of BIR measurement in five farmlands each located in Nkalagu, Ezillo, Okpoto and Nteze communities was carried out using portable GQ GMC-320 Plus radiation meter at an elevation of 1.0 m above ground level with a GPS for geographical location. The BIR levels observed in Nkalagu and Ezillo farmlands are high ranging with same mean values of 0.016±0.002mR/h which is higher than 0.013 mR/h ICRP recommendations for normal environment. The BIR measured at Okpoto and Nteze farmlands are low ranging with mean values of 0.013±0.001 mR/h which is in tandem with ICRP recommendation. The corresponding absorbed doses in all the farmlands and associated excess lifetime cancer risks are far higher than their recommended safe limit of 84.0 ηGy/h and 0.29×10^-3 respectively. The values for the annual effective dose for all the farm lands are lower than the permissible limits of 1.00 mSv/yr for the general public. The study shows that the radiation levels and the doses observed in the farmlands do not constitute any immediate negative radiological health effect on the farmers and general public. However, there exists the possibility of cancer development due to accumulated doses as suggested by the excess lifetime cancer risk values.

Keywords
Background radiation levels; absorbed doses; farm lands; Ishielu communities