Yehuwdah E. Chad-Umoren

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

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.

Ionizing Radiation Profile of the Hydrocarbon Belt of Nigeria

Man and his environment are constantly bombarded with naturally occurring ionizing radiation. However, aside from the radiation occurring naturally in the human environment, there are those resulting from man’s activities. These anthropogenic activities result in the elevation of the background ionizing radiation levels mainly through the depletion of the ozone layer so that an increase occurs in the amount of cosmic radiation reaching the earth (Foland et al, 1995). One crucial area of human activity is the hydrocarbon industry. Globally, the hydrocarbon industry is a strategic industry, contributing to the wealth of nations and the prosperity of individuals. Global economy is often appreciably impacted by the stability or otherwise of the industry. Furthermore, much of the world’s population is dependent on the industry for its energy needs. Significantly also, the processes and techniques of oil and gas exploration, exploitation and usage contribute to the devastation, pollution and degradation of the environment. In Nigeria, the hydrocarbon industry is reputed to be the highest user of radioactive substances in the country (Chad-Umoren and Obinoma, 2007). And the Niger Delta region of Nigeria plays host to the largest concentration of companies in this sector. The maze of crisis-crossing pipelines in the region (Fig.1) does not only transport oil and gas, but also dangerous radioactive substances so that the environment is not despoiled only during oil spillage, but is also polluted with harmful ionizing radiation. Also abundant in the region are numerous non-oil and gas industries and operations that have been attracted into the region by its oil and gas wealth.