Annual intakes of 226Ra, 228Ra and 40K in staple foodstuffs from a high background radiation area in the southwest region of Cameroon

Concentrations of naturally occurring radionuclides 226Ra, 228Ra and 40K were determined in five most consumed vegetables in a high-level background radiation area (HLBRA) in the southwest region of Cameroon. A total of 25 foodstuff samples collected from Akongo, Ngombas, Awanda, Bikoué and Lolodorf rural districts were analyzed by gamma spectrometry. The average activity concentration values of 226Ra, 228Ra and 40K were respectively 2.30, 1.50 and 140.40 Bq kg−1 fresh-weights. The effective dose for individual consumption of the investigated foodstuff types was calculated on an estimated annual intake of such diets in the study area. The estimated total daily effective doses from the ingestion of the investigated foodstuffs for each studied long-life natural radionuclide were respectively 0.41 μSv for 226Ra, 0.84 μSv for 228Ra and 0.71 μSv for 40K. The total annual effective dose was estimated at 0.70 mSv y−1. 228Ra (44%) and 40K (36%) were found to be the main sources for internal irradiation which is very likely due to the specific uptake of these radionuclides by the studied plants.

► 226Ra, 228Ra and 40K concentrations in foodstuffs from five HBRA in Cameroon investigated.
► It contains data related to 25 foodstuff samples collected from the rural districts.
► The dietary intakes and the annual effective doses were calculated.
► Determined annual committed effective doses are higher than UNSCEAR data.