Evaluation of background ionizing radiation to estimate effective dose and excess lifetime cancer risk from two major dumpsite in Calabar, Nigeria

By using a chamber radiation survey meter, meter rule to measure distance between data points, and a geographical positioning system (GPS) to measure the coordinate of the study area, the study of background ionizing radiation levels in Calabar the metropolis has been conducted to assess the effective dose to the body's organs and tissues as well as the excess lifetime cancer risk. The elevation level of the chamber survey meters was maintained at 1.0 meters above the ground. The average BIR absorbed dose rate, annual effective dose equivalent, excess lifetime cancer risk, and effective dose to the organs and tissues were among the radiological hazard characteristics that were assessed. From the results of the mean radiological hazard indices from the study are BIR dose rate is 0.03±0.003 (µSv/h), ADR is 33±3.10 nGy/h, AEDE 0.04±0.004 mSv/y, ELCR is 0.14±0.013mSv/y while EDR was 1.4±0.07mSv/y for Udeme dumpsite. In Lemna dumpsite we have the following radiological hazard indices mean values, the BIR dose rate 0.04±0.03, ADR of 29±3.8nGy/h, AEDE 0.0 4± 0.005 mSv/y, ELCR is 0.12±0.016 while EDR is 1.7±0.16 respectively. All the calculated radiological hazard parameters are below the recommended dose limit of 1mSv/y by UNSCEAR, ICRP, IAEA and WHO. Even the ELCR is less than the recommended dose limit of 0.29 mSv/y, except effective dose to the organs and tissues which are relatively above recommended threshold at both dumpsites. The results show that the estimated dose to various body organs and tissues are relatively higher than the recommended 1.0mSv/y. The food nutrient absorption rate within the study area justifies the relatively lower dose consumption for the brain, skin, and bone and the comparatively greater dose for the heart, pancreas, and prostate.