Chidozie Timothy Akpa

Bio: Chidozie Timothy Akpa is an academic researcher. The author has contributed to research in topics: Tailings. The author has an hindex of 1, co-authored 1 publications receiving 20 citations.

Health and ecological hazards due to natural radioactivity in soil from mining areas of Nasarawa State, Nigeria

Abstract: Nasarawa State is located in north central Nigeria and it is known as Nigeria's home of solid minerals. It is endowed with barite, copper, zinc, tantalite and granite. Continuous releases of mining waste and tailings into the biosphere may result in a build-up of radionuclides in air, water and soil. This work therefore aims to measure the activity concentration levels of primordial radionuclides in the soil/sediment samples collected from selected mines of the mining areas of Nasarawa State. The paper also assesses the radiological and radio ecological impacts of mining activities on the residents of mining areas and their environment. The activity concentrations of primordial radionuclides ((226)Ra, (232)Th and (40)K) in the surface soils/sediment samples were determined using sodium iodide-thallium gamma spectroscopy. Seven major mines were considered with 21 samples taken from each of the mines for radiochemistry analysis. The human health hazard assessment was conducted using regulatory methodologies set by the United Nations Scientific Committee on the Effects of Atomic Radiation, while the radio ecological impact assessment was conducted using the ERICA tool v. 1.2. The result shows that the activity concentrations of (40)K in the water ways of the Akiri copper and the Azara barite mines are 60 and 67% higher than the world average value for (40)K, respectively. In all mines, the annual effective dose rates (mSv y(-1)) were less than unity, and a maximum annual gonadal dose of 0.58 mSv y(-1) is received at the Akiri copper mine, which is almost twice the world average value for gonadal dose. The external hazard indices for all the mines were less than unity. Our results also show that mollusc-gastropod, insect larvae, mollusc-bivalve and zooplankton are the freshwater biotas with the highest dose rates ranging from 5 to 7 µGy h(-1). These higher dose rates could be associated with zinc and copper mining at Abuni and Akiri, respectively. The most exposed terrestrial reference organisms are lichen and bryophytes. In all cases, the radio ecological risks are not likely to be discernible. This paper presents a pioneer data for ecological risk from ionizing contaminants due to mining activity in Nasarawa State, Nigeria. Its methodology could be adopted for future work on radioecology of mining.

Activity concentrations of 226Ra, 228Ra, 222Rn and their health impact in the groundwater of Jordan

Abstract: The activity concentrations of 226Ra, 228Ra and 222Rn were measured in 87 groundwater samples to estimate the activity concentrations of these radionuclides and health impact due to intake of these radionuclides in groundwater of Jordan. The mean activity concentrations of 226Ra, 228Ra and 222Rn in groundwater were found to be 0.293 ± 0.005 Bq L−1, 0.508 ± 0.009 Bq L−1 and 58.829 ± 8.824 Bq L−1, respectively. They give a mean annual effective dose of 0.481 mSv with mean lifetime risk of 24.599 × 10−4, exceeding the admissible limit of 10−4. Most of the received annual effective dose (59.15% of the total) is attributed to 228Ra.

Radionuclide concentrations and excess lifetime cancer risk due to gamma radioactivity in tailing enriched soil around Maiganga coal mine, Northeast Nigeria

Abstract: Background: Human ac vi es such as mining enhance the radioac vity levels above normal background which can lead to an incremental increase in the radia on risk to the popula on. Materials and Methods: 20 tailing enriched soil samples collected around Maiganga coal mine, Gombe, Northeast Nigeria were assessed for their Ra, Th and K contents using HPGe gamma-ray detector. Results: The mean ac vity values of 11.90±3.0, 17.72±3.6 and 70.44±20.4 Bq kg were obtained for Ra, Th and K respec vely. These values were below the world average values documented by UNSCEAR. The ra o of Th:Ra obtained was 1.5, which showed that Th ac vity was higher than the ac vity of Ra while K recorded the highest ac vity concentra on in the studied samples. Sta s cal analysis iden fied strong posi ve rela onships among all radiological parameters and confirmed that Ra, Th and K were the major contributors to radia on dose. Radium equivalent ac vity (Raeq), absorbed gamma dose rate (DR), annual effec ve dose (AEDE), ac vity u liza on index (AUI), external and internal hazard indices (Hex and Hin), gamma representa ve index (Iγr), annual gonadal dose (AGDE) and excess life me cancer risk (ELCR) were calculated to quan fy the radia on risk to the public from exposure to Ra, Th and K in the studied samples. The mean values of these hazard parameters were within the acceptable limits provided for human safety and environmental protec on. Conclusion: The use of the tailing enriched soil samples of Maiganga coal mine for any purpose whatsoever does not therefore pose any immediate radiological risk to the coal workers or the general public.