Environmental Radioactivity, Ecotoxicology (Uranium-238, Thorium-232 and Potassium-40) and Toxic Heavy Metals Contents in Water and Sediments from North Africa Dams. Tuniso-Algerian Transboundary Southern Mediterranean Basin

Abstract

Natural radioactivity of 238U, 232Th and 40K for liquid and solid samples collected from Sidi Salem dam (Tunisia) and Aïn Dalia dam (Algeria) were measured using TERRA detector of rays (gam-ma, beta, and alpha), Atomic adsorption and Gamma-ray spectrometry were used to analyze the levels of radionuclides and toxic heavy metals, respectively. Toxic heavy metals (Fe, Bb, Zn, Ni, Cu, Cr and Cd) and associated health risks in surface water and sediment of dams have been in-vestigated in this present study. The radioactivity mean rates in the water samples were 1.72±0.01, 0.068±0.01 and 94.6±1.04 Bql-1 for 238U, 232Th and 40K respectively (Tunisia dam) and were 1.9± 0.24, 0.09±0.01 and 131.43±1.03 Bql-1 for 238U, 232Th and 40K respectively (Algeria dam). The 238U, 232Th and 40K radioactivity mean concentration measured in the sediment samples were 2.67±0.01, 0.18±0.012 and 197.87±2.01 Bqkg-1 respectively (Tunisian dam) and were 4.34±0.05, 0.27±0.05 and 287.61±3.34 Bqkg-1 respectively (Algeria dam). The activity concentration of 40K was higher than that of 238U and 232Th for the water and sediment samples. The mean activity concen-trations follow the order 40K > 238U > 232Th. The cumulative impact can be a serious immediate radiological health burden on the ecosystem, environment and people's health in this study area and can be transposable to any other similar region. The good knowledge of monitoring quality and quantity for the transboundary water resources and the international collaborations are es-sential to safeguard human health (women’s breasts cancer, thyroid cancer, neurological im-pact…), and avoid the conflicts, especially during these climatic upheavals of drought.