Cadmium, manganese, mercury and lead in the general adult population of Kinshasa, DR Congo

Abstract

Background and Aim. Many metals are of health concern due to their toxic proprieties and health impairments in the human body. To evaluate values for the internal exposure in the general population, the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) and the International Union of Pure and Applied Chemistry (IUPAC), recommend the use of reference intervals (RIs) of metals as an indicator of the background exposures. This work aimed to derive RIs for Cd, Hg, Mn and Pb in the blood and urine of the adult population living in Kinshasa (n = 396, aged 18-70 years with 210 females). Methods. Levels of metals were measured using Inductively Coupled Argon Plasma - Mass Spectrometry (ICP-MS). Results. In blood, the proposed RIs [P5-P95 (GM)] were 0.089-2.365 µg/L (0.262), 41.41-199.20 µg/L (84.43), 0.100-1.964 µg/L (0.450) and 6.014-15.380 µg/L (9.394) for Cd, Pb, Hg and Mn, respectively. Urinary levels [(P5-P95 (GM)] were 0.142-1.430 µg/L (0.458) for Cd, 1.910-17.840 µg/L (5.424) for Pb, 0.349-2.295 µg/L (0.816) for Hg and 0.063-1.340 µg/L (0.188) for Mn. Conclusion. Except for Pb, levels of all metals were significantly lower than those found in the same city in 2012 and similar to databases involving non-occupationally exposed populations from other countries, probably due to exclusion criteria of metal exposure applying in the present survey (occupationally exposed to the studied metals, smoking habits, amalgam tooth fillings, fish consumption habit more than one time per week, etc.). These background metal exposures will be useful for future occupational and/or environmental surveys as well as undertaking a reliable regulation of chemical exposure in Kinshasa via a national HBM program.