Distribution of gamma-ray emitting radionuclides in the marine environment of the Burullus Lake: II. Bottom sediments

The sediment compartment has the ability to trap large amounts of radionuclides and to indicate the radiological impact of pollution. The present work shows the results obtained related to the concentrations of Cs-137 and natural radionuclides in sediment in the Burullus Lake, Egypt. The average values of Ra-226, Th-232, and K-40 in the bottom sediments collected from the east of the Burullus Lake ranged from 10.3 to 21.8 Bq/kg, from 11.9 to 34.4 Bq/kg, and from 268 to 401 Bq/kg, respectively. The study has shown that K-40 concentration is nearly uniform throughout the studied area while Ra-226 and Th-232 are more concentrated in the northeastern shore. Lake sediments showed contamination with Cs-137 (2.7-15.9 Bq/kg). The Cs-137 sediment activities indicated higher concentrations in the off-shore sites. Concentrations of all gamma -ray emitting radionuclides except K-40 in water samples were below the detection limits. The K-40 sediment-water distribution coefficients of the near-shore samples were higher than the off-shore samples.