Evaluation of 20 toxic metals and essential elements in the blood of metal recycling tinsmiths of Cotonou (Benin)

It is common for trainees and craftsmen in the informal economy to not use protective equipment. With tinsmiths, exposure to toxic emissions such as fumes of molten metal that may contain metallic particles is likely to lead to uptake of toxic metals. Aims: The principal aim of this study was to evaluate the biological concentrations of toxic metals and essential trace elements in tinsmiths, craftsmen, and trainees working in the informal sector of Cotonou in Benin. Materials and Methods: Twenty metallic trace elements were measured in whole blood from 111 adult male tinsmith craftsmen, while only the blood lead level was measured in twenty-four trainees of less than 18 years of age. The blood samples were collected at the ERASME health center of Cotonou, using 6 ml EDTA-K2 trace element tubes. The analyses were performed by ICP-MS (Inductively Coupled Plasma-Mass Spectrometry) with a NexION 350 D (PerkinElmer) spectrometer. The results obtained were then compared to those obtained with a reference population that was not subject to professional exposure. Results: For three trace elements, more than 25% of the adult tinsmiths exhibited blood concentrations above the biological reference values. By increasing order of uptake, these were antimony (28.8%), tin (31.5%), and lead (71.2%). For trainees under 18year of age, the prevalence of workers with a blood lead level ≥ 100 µg/L was 83%. Conclusions : Exposure to lead was the greatest concern, and protection and awareness measures should be implemented so as to decrease the health risks linked to lead exposure, particularly among young workers.