Recovering and restitution of unknown, unidentified, and unlabeled samples in laboratories using EDXRF analysis

Assessment of heavy metals' pollutions and potential risks associated to the rocks of Pouma subdivision-Cameroon

The present study aimed to assess the ecological and health risks of the Pouma rock samples. Twenty-three (23) trace element concentrations were evaluated. The concentrations of these trace elements were compared with those of quartzite from other countries and with global reported values. When compared with the world values, the concentrations of trace metals were below the world average values except that of Barium. The ecological risk assessment was carried out using the geo-accumulation index, contamination factors and the potential ecological risk index. The geo-accumulation index and contamination factors showed that the quartzite of Pouma subdivision are not polluted and not contaminated by the investigated metal except for Barium and Mercury. The health risk assessment using the USEPA (United States Environmental Protection Agency) method showed that there is a possible non-carcinogenic risk from Al2O3 (for children and adults) and from Cr for Children. However, there is a tolerable and high carcinogenic risk due to Cr for adults and children, respectively. It was found independently for non-carcinogenic and carcinogenic risk that the exposure via the ingestion route is the most dangerous for adults and children.

Assessment of trace elements pollution and their potential health risks in the cobalt-nickel bearing areas of Lomié, East Cameroon

A study of trace elements pollution in the cobalt-nickel mining area of Nkamouna-Kongo (East Region of Cameroon) and their intimation to the risk of human exposure was carried out. A large spatial variability of concentrations was observed in the geochemical analysis of the trace elements in the thirty samples investigated. Trace element pollution in the investigated samples was assessed using the Regional Screening Level calculator of Environmental Protection Agency (USEPA) and the collected sample were analyzed using a SPECTRO XEPOS Energy Dispersive X-Ray Fluorescence analyzer (ED-XRF). The trace element concentrations in the analyzed samples followed the following order: Fe > Cr > Mn > Zr > Ni > Ba > Rb > Cu > Zn > Sr > Ga > Pb > Co > Rb > As > Sn. The averages of trace elements contamination factors followed a decreasing order:: Cr > Ni > Fe > As > Co > Cu > Zr > Ga > Pb > Mn > Zn > Y > Rb > Ba > Sn > Sr. Enrichment factor studies revealed that chromium (Cr) was severely enriched (indicating that Cr is the main element of the anthropic load) while elements such as Ni, Ba, Mn, Co, Cu, Zn, Ga, As, and Pb were moderately enriched. The associated health risk of human exposure was investigated using the Regional Screening Level of Environmental Protection Agency. It was found out that the carcinogenic risk to the exposed population from ingestion is high (2.5E-03), while the dermal risk is moderate (7.08E-04) and the inhalation risk is low (2.50E-07). The total non-carcinogenic risk from trace elements exposure for adults (HI = 1.5) and children (HI = 1.47E + 01) indicates that non-carcinogenic effects may occur in the vicinity of the study area.