Titre du document / Document title

A survey of background radiation dose rates and radioactivity in Tanzania

Auteur(s) / Author(s)

BANZI F. P. ⁽¹⁾ ; MSAKI P. ⁽¹⁾ ; MAKUNDI I. N. ⁽¹⁾ ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

⁽¹⁾ Physics Department, University of Dar es Salaam, P.O. Box 35063, Dar es Salaam, TANZANIE, REPUBLIQUE-UNIE DE

Résumé / Abstract

Potential terrestrial sources of naturally occurring elevated radiation levels have been identified in Tanzania. Thus, efforts are currently being undertaken to create a natural radiation database, in the form of a radiation level map of natural radioactivity, to be used to assess the associated radiation risk to public and workers. Background radiation dose rate was determined with thermoluminescent dosimeters for 7 y (1993-1999) in five stations. The average background radiation dose rates for these stations were as follows: Tropical Pesticides Research Institute (TPRI) (102 ± 7 nGy h^-1), Same (98 ± 2 nGy h^-1), Namanga (98 ± 5 nGy h^-1), University of Dar Es Salaam (99 ± 2 nGy h^-1), and Kilimanjaro Christian Medical Center (121 ± 3 nGy h^-1). These stations were found convenient from an economic point of view since the project has no funds to cover wider and/or more remote areas in Tanzania. For the sake of comparison, similar measurements were made for the same period at Minjingu phosphate mine. The mine was one of the suspected areas with elevated levels of natural radioactivity. The radiation dose rate measured in this mine was about fourteen times higher (1,415 ± 28 nGy h^-1) than the average value obtained in northern Tanzania (98 nGy h^-1). The high average activity levels of phosphate (5760 ± 107 Bq kg^-1 for ²²⁶Ra, 497 ± 5 Bq kg^-1 for ²²⁸Ra, 350 ± 6 Bq kg^-1 for ²²⁸Th, and 280 ± 5 Bq kg^-1 for ⁴⁰K) and radiation dose rate recorded show that Minjingu phosphate mine has higher values than the highest radioactivity in phosphate compiled by the United Nations Scientific Committee on the Effect of Atomic Radiation. In view of these findings, a comprehensive risk-management strategy for reduction of radiation risk to the public and mine workers should be put in place. Efforts are currently being made to seek support to improve the background radiation database for subsequent assessment of radiation risk to miners and the societies in the vicinity of these mines in Tanzania.

Revue / Journal Title

Health physics   ISSN 0017-9078   CODEN HLTPAO 

Source / Source

2002, vol. 82, n^o1, pp. 80-86 (19 ref.)

Langue / Language

Anglais

Editeur / Publisher

Lippincott, Hagerstown, MD, ETATS-UNIS  (1958) (Revue)

Mots-clés anglais / English Keywords

Public health ; Geology ; Nuclear physics ; Africa ; Tanzania ; Human ; Background radiation ; Dosimetry ; Radioisotope ; Assay ; Radioactive contamination ; Natural hazard ; Natural radioactivity ;

Mots-clés français / French Keywords

Santé publique ; Géologie ; Physique nucléaire ; Afrique ; Tanzanie ; Homme ; Rayonnement fond ; Dosimétrie ; Radioisotope ; Dosage ; Radiocontamination ; Risque naturel ; Radioactivité naturelle ;

Mots-clés espagnols / Spanish Keywords

Salud pública ; Geología ; Física nuclear ; Africa ; Tanzania ; Hombre ; Radiación fondo ; Dosimetría ; Radionúclido ; Dosificación ; Radiocontaminación ; Riesgo natural ; Radioactividad natural ;

Localisation / Location

INIST-CNRS, Cote INIST : 9288, 35400009469173.0080