Assessment of Uranium in Drinking Water in Kitwe, Chambeshi and Chingola in the Copperbelt Region of Zambia

The paper discusses uranium in drinking water in three towns located in the uraniferous Copperbelt region of Zambia. The mining towns of Kitwe, Chambeshi and Chingola in the Copperbelt region have two main sources of drinking water: underground mine water and surface water from the Kafue River system. Chambeshi abstracts its water from underground while Chingola abstracts water from both underground and surface water sources. Kitwe abstracts water from the Kafue River which drains the entire Copperbelt region. In Zambia, World Health Organization (WHO) guidelines for drinking water are followed, although routine monitoring for radioactivity is not mandatory. The overall objective of this study was to gather baseline data on uranium contamination in drinking water and compare with the WHO guidelines and also to establish the source with the highest levels of uranium. An alpha spectrometer was used to analyse the samples and the results from this survey indicate that the average total uranium activity concentrations were in the range of 78.50 mBq/L in Kitwe to 600.78 mBq/L in Chambeshi. The committed effective doses for adults were in the range of 3.58 μSv/a in Kitwe to 20.28 μSv/a in Chambeshi. From both water sources, the committed effective doses were below the WHO guideline reference dose level of 100 μSv/a. The uranium activity concentration for Chambeshi was above the recommended screening level for alpha emitters in drinking water of 500 mBq/L. The average ²³⁵U:²³⁸U ratio was 0.046, the natural abundance ratio for uranium. (author)