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

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.