Risk assessments and spatial distributions of natural radioactivity and heavy metals in Nasser Lake, Egypt.

Nasser Lake provides more than 95% of the Egyptian freshwater budget. The levels, spatial distributions, and risk assessments of heavy metals and natural radioactivity were investigated in the water and sediments in the main channel and khors (side extensions) of Nasser Lake in January 2017. Several indices were used to determine the quality and pollution degree of the water and sediments.