In accordance with the international safety requirements, particularly those established by the International Atomic Energy Agency (IAEA) in the General Safety Requirements (GSR part 3), materials containing naturally occurring radionuclides from the uranium and thorium decay series with an activity concentration of 1 Bq/g are generally considered to fall within the scope of regulatory control. This work was devoted to the analysis of variability of specific activity of cobalt hydroxides from four companies in the city of Kolwezi, particulary those reputed to have deposits slightly enriched in radioactive materials. Nearly 150 samples were collected to carry out this study, and the specific activities were calculated after analysis using an X-ray fluorescence spectrometer. The activity concentration determined in the present study remains below this reference level. Nevertheless, the findings warrant a documented radiological assessment conducted under a graded approach to radiation protection. Consistent with the fundamental principles of radiation protection recommended by the IAEA namely justification, optimization and dose limitation- the measured radiological levels indicate that handling, storage, and transport operation may be performed under normal operating conditions. This conclusion is contigent upon the implementation of good industrial practices and the establishment of periodic radiological monitoring to ensure continued compliance with regulatory standards.

Environmental radiological assessment is an essential process for characterizing human exposure levels in order to limit or reduce the risks associated with exposure to ionizing radiation. The approach involves identifying the transfer pathways of radionuclides and assessing the potential risks to ecosystems and nearby populations. To optimize the use of resources and adapt the level of analysis to the degree of radiological risk, international radiation protection organizations recommend the application of the graded approach in radiological impact studies. This approach consists of adjusting the depth and complexity of the assessment according to the potential significance of the radiological impacts associated with a given activity. Indeed, after energy and efficiency calibration, the peaks identified and correct for background radiation show that the calculated mass activities obtained after peak integration do not indicate any abnormal levels. Thus, the results of this study will contribute to establishing a database for environmental radiological monitoring.