Article

Dose estimates to the public due to ²¹⁰Po ingestion via cocoa powder from Lolodorf high background radiation area, Cameroon

¹ Nuclear Physics Laboratory, Faculty of Science, University of Yaoundé I, P.O. Box 812, Yaoundé, Cameroon
² National Radiation Protection Agency, P.O. Box 33732, Yaoundé, Cameroon

^* Corresponding author: bajeanfelix@yahoo.fr

Received: 12 March 2018
Accepted: 9 May 2018

Abstract

²¹⁰Po activity concentrations have been measured in Lolodorf high background radiation area in cocoa beans which are hand-processed into cocoa powder for breakfast purposes to estimate radiological dose to human. ²¹⁰Po has been also measured in cocoa leaves and compared to the cocoa beans ²¹⁰Po content. The analysis has been carried out by CANBERRA alpha spectrometry using ion-implanted silicon detectors. ²¹⁰Po activity concentrations in cocoa beans varied from 2.31 ± 0.23 to 8.09 ± 0.56 Bq.kg⁻¹, while these values varied from 21.7 ± 0.87 to 66.67 ± 1.58 Bq.kg⁻¹ in cocoa leaves. The corresponding mean values are 4.96 ± 1.86 and 42.54 ± 16 Bq.kg⁻¹ on a dry weight basis respectively. The obtained values confirm the fact that ²¹⁰Po activity concentrations in cocoa leaves are high compared to the cocoa beans due to the deposition of ²²²Rn daughters in the atmosphere. The mean radiological doses to human were founded to be 0.227, 0.134, 0.083 and 0.062 mSv/year for children 2- to 7-year-olds, 7- to 12-year-olds, 12- to 17-year-olds and for adult respectively. Ingestion of cocoa powder by the most exposed group ages (children) might not exceed the recommended dose limit for members of the public, which is 1 mSv/year.