Baseline radionuclide and heavy metal concentrations in sediments of Sabaki River estuary (Kenya, Indian Ocean). (March 2021)

• Record Type: Journal Article
• Authors: Wanjeri, V.W.O.; Okuku, E.O.; Barsanti, M.; Schirone, A.; Delbono, I.; Owato, G.; Delfanti, R.
• Is Part Of: Marine pollution bulletin. Volume 164(2021)
• Publication Date: 2021-03
• Subjects: Sabaki River estuary -- Radionuclides -- Heavy metals -- Flood signature -- ERICA tool -- Dose rate; Marine pollution -- Periodicals; Marine Biology -- Periodicals; Water Pollution -- Periodicals; Mer -- Pollution -- Périodiques; Publications périodiques; Pollution des mers; Lutte antipollution; Electronic journals; 363.7394
• DOI: 10.1016/j.marpolbul.2021.112033
• Languages: English
• ISSNs: 0025-326X

Abstract

Abstract: Baseline study of natural ( 7 Be, 210 Pb, 226 Ra, 234 Th, 228 Ra, 40 K) and anthropogenic ( 137 Cs) radionuclides was carried out in two cores collected from Sabaki River estuary (Kenya, Indian Ocean). There was no exponential decrease of excess 210 Pb down the cores, which did not allow dating and determination of heavy metal pollution history. The use of 137 Cs as a time marker was not possible due to its low fallout rates in East Africa. The short-lived radioisotope 7 Be, a tracer of river floods, confirmed 2018 flood in Sabaki River estuary. Heavy metal concentration in the two cores showed nonsystematic trends with depth. Only Pb concentration in Sabaki River estuary was higher than the background levels. Application of the "Environmental Risk from Ionising Contaminants Assessment and management" (ERICA) tool confirmed that the potential dose rates to biota from the sediment radioactivity concentrations are unlikely to pose appreciable ecological risks. Highlights: Baseline study of natural and anthropogenic radionuclides Vertical distribution of heavy metals and radionuclides in sediment Sabaki River flood signature through 7 Be Radioecological risk assessments to marine organisms