Estimating the probability of cancer induction due to occupational exposure in Ghana

The probability of cancer induction was estimated from data for Occupationally Exposed Workers (OEWs) in some medical facilities within the ten (10) regions of Ghana. The dose data covered 535 personnel from 60.5% of the total number of personnel monitored (884) in all medical facilities in Ghana for the ten-year period (2000-2009). The individual monitoring service is provided by the Radiation Protection Institute of Ghana Atomic Energy Commission. The mean annual effective dose estimated for the period ranged between 0.48 mSv and 0.71 mSv with a mean value of 0.58 mSv, which is in line with the trend in other countries undertaking similar investigations. The mean annual collective doses ranged between 7.80 x 10-3 man.Sv and 13.45 x 10-3 man.Sv with a mean value of 10.52 x 10-3 man.Sv, which is much lower than the values of other advanced countries because of the very low numbers of personnel monitored. The detriment-adjusted nominal risk coefficients (10-2 sv-1) for stochastic effects after exposure to radiation at low dose rate proposed by ICRP was used to estimate cancer risk, hereditary effects risk and total detriment. The estimated mean annual cancer risks are 2.28 x 10-5 ± 2.02 x 10-6 using the 2007 and 1990 ICRP risk models respectively. The corresponding estimated mean lifetime cancer are 1.14 x 10-3 ± 1.18 x 10-4 respectively. The values were within the range of values estimated by international organizations such as Biological Effects of Ionizing Radiation Committees (BEIR II and III) and United Nations Science Committee on the Effects Atomic Radiation (au).