Natural radioactivity levels of some medicinal plants commonly used in Ghana

Natural radioactivity levels in some selected medicinal plants commonly used in Ghana from the Centre for Scientific Research into Plant Medicine were investigated to determine the activity concentration and the annual committed effective dose due to naturally occurring radionuclides of (238)U, (232)Th and (40)K. The activity concentration was determined using gamma-ray spectrometry. The results of the analysis indicated an average activity concentration of (238)U, (232)Th and (40)K in the medicinal plants to be 31.8±2.8 Bq kg(-1), 56.2±2.3 Bq kg(-1) and 839.8±11.9 Bq kg(-1) respectively. Khaya ivorensis recorded the highest activity concentration of (238)U and (232)Th while Lippia multiflora recorded the highest activity concentrations of (40)K. The total annual committed effective doses ranged from 0.026±0.001 to 0.042±0.002 mSv a(-1) with an average value of 0.035±0.001 mSv a(-1). The average annual committed effective dose due to ingestion of the natural radionuclides in the medicinal plant samples were far below the world average annual committed effective dose of 0.3 mSv a(-1) for ingestion of natural radionuclides provided in UNSCEAR 2000 report. Therefore, the radiological hazard associated with intake of the natural radionuclides in the medicinal plants is insignificant. The results provide baseline values which may be useful in establishing rules and regulations relating to radiation protection as well as developing standards and guidelines for the use of medicinal or herbal plants to the appropriate authorities

Radiological landscape of natural resources and mining: Unveiling the environmental impact of naturally occurring radioactive materials in Ghana's mining areas

This study provides a general observation of the status of naturally occurring radioactive materials (NORMs) distribution in mining and industrial areas of Ghana in order to establish regional and national data on NORMs. The study includes data on radioactivity concentrations of U-238, Th-232, and K-40 in soils and for water concentrations of Ra-226, Th-228, and K-40 from various mining, oil, and gas communities, as well as water sources used for crop farming and farmlands. The average activity concentrations of U-238, Th-232, and K-40 in the soil samples were found to be 59 ± 16 Bq/kg, 48 ± 15 Bq/kg, and 286 ± 57 Bq/kg, respectively. The average concentration of Ra-226, Th-228, and K-40 in the water samples were found to be 1.62 ± 0.33 Bq/L, 2.08 ± 0.53 Bq/L, and 22.36 ± 3.44 Bq/L, respectively. The estimated average annual effective doses from external and internal exposure pathways in soil and water samples were 0.09 mSv/y and 0.54 mSv/y, respectively. The total annual effective dose resulting from both exposure pathways was calculated to be 0.63 mSv/y, which is below the 1 mSv/y dose limit recommended by the International Commission on Radiological Protection (ICRP) for controlling public radiation exposure. Based on the radiological hazard indices, the majority of the soil samples were found to be suitable as building materials as their respective indices were below the limits except for two sample locations and the sludge and scale samples. The average Excess Lifetime Cancer Risk (ELCR) value of the water samples was 1.6 times greater than the recommended value of 1.16 × 10−3, presenting a relatively higher risk to the public of developing cancer. No significant regional differences in the levels of radioactive elements. The regression models demonstrate strong interrelationships between the studied elements, with high R-squared values suggesting a predictable nature of one element’s concentration based on others