Impact of Gas Exploitation on the Environmental Radioactivity of Ogba/Egbema/Ndoni Area,Nigeria

Abstract

A key component of the current national energy policy of Nigeria is to efficiently utilize her abundant natural gas reserves, especially in the energy sector. This paper reports a study of the terrestrial radioactivity in the industrial areas of Ogba/Egbema/Ndoni Local Government Area (ONELGA) of Rivers State. These industrial areas and their host communities were divided into six (6) zones, each having an oil and gas facility. An in-situ measurement was done using two well calibrated nuclear radiation meters (digilert–100 and digilert–50) and geographical positioning system (GPS). Ten readings were taken in each of the six zones and the host community at randomly selected sites, making a total of 60 sampling points. The mean site radiation level ranges from 0.014 ± 00.001mRh⁻¹ (1.183 ± 0.060mSvy⁻¹) to 0.018 ± 0.002mRh⁻¹ (1.689± 0.085mSvy⁻¹) while the mean community radiation level ranges from 0.014 ± 0.001mRh⁻¹ (1.183 ± 0.06mSvy⁻¹) to 0.017 ± 0.001mRh⁻¹ (1.435 ± 0.072mSvyr¹). The equivalent dose has an average range of 1.056 mSvy⁻¹ to 2.871 mSvy⁻¹, which is far below the recommended dose limit for radiological workers (20mSvy⁻¹) but averagely above that for the general public (1mSvyr⁻¹). Comparison of the measured radiation level of site locations with the normal background level shows that 43 locations, representing 71.7% of the sampled area, exceed the normal background level of 0.013mRh⁻¹. This study indicates that there is no immediate radiological health hazard for the host communities and workers, however there may be long-term health challenges.