High human exposure to cobalt and other metals in Katanga, a mining area of the Democratic Republic of Congo

• Published in: Environmental research Vol. 109; no. 6; pp. 745 - 752
• Main Authors: Banza, Célestin Lubaba Nkulu, Nawrot, Tim S., Haufroid, Vincent, Decrée, Sophie, De Putter, Thierry, Smolders, Erik, Kabyla, Benjamin Ilunga, Luboya, Oscar Numbi, Ilunga, Augustin Ndala, Mutombo, Alain Mwanza, Nemery, Benoit
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01.08.2009; Elsevier
• Subjects: Adolescent; Adult; Africa; Aged; Arsenic; Arsenic - urine; Biological and medical sciences; Biomonitoring; Cadmium; Chemical and industrial products toxicology. Toxic occupational diseases; Child; Child, Preschool; Children; Cobalt; Cobalt - urine; Creatinine; Environmental Exposure - analysis; Environmental justice; Environmental Monitoring - methods; Environmental Pollutants - urine; Environmental pollution; Female; Humans; Lead (metal); Male; Medical sciences; Metals; Metals and various inorganic compounds; Metals, Heavy - urine; Middle Aged; Mines; Mining; Toxicology; Uranium; Young Adult; Congo; Africa; Congo, Dem. Rep., Katanga; Mining; Biomonitoring; Uranium; Environmental pollution; Arsenic; Metals; Africa; Children; Cobalt; Environmental justice; Human; Proximity; Transition metal; Exposure; Epidemiology; Biological monitoring; Residential zone; Pollution; Mine; Environment; Woman; Child; Public health
• ISSN: 0013-9351; 1096-0953; 1096-0953
• DOI: 10.1016/j.envres.2009.04.012

The human health impact of the historic and current mining and processing of non-ferrous metals in the African Copperbelt is not known. This study assessed the exposure to metals in the population of Katanga, in the south east of the Democratic Republic of Congo, using biomonitoring. Seventeen metals (including Cd, Co, Cu, Pb, U) and non-metals (including As) were measured by ICP-MS in urine spot samples from 351 subjects (32% women), aged 2–74 yr (mean 33 yr). Forty subjects (controls) lived 400 km outside the mining area; 311 subjects lived in the mining area, either very close (<3 km) ( n=179; 6 communities) or moderately close (3–10 km) ( n=132; 4 communities) to mines or smelting plants. For all metals (except Ni) urinary concentrations were significantly higher in subjects from the mining area than in control subjects. In subjects living very close to mines or smelting plants, the geometric means (25th–75th percentile) of urinary concentrations, expressed as μg/g creatinine, were 17.8 (10.9–29.0) for As, 0.75 (0.38–1.16) for Cd, 15.7 (5.27–43.2) for Co, 17.1 (8.44–43.2) for Cu, 3.17 (1.47–5.49) for Pb and 0.028 (0.013–0.065) for U, these values being significantly higher than those of subjects living 3–10 km from mines or industrial operations. Urinary Co concentrations were markedly elevated, exceeding 15 μg/g creatinine in 53% of the subjects, and even 87% of children (<14 yr), living very close to the mining areas. Urinary As was also high (79% above 10 μg/g creatinine in subjects living very close to the mining areas). Compared with background values from the US general population, subjects living very close to areas of mining or refining had 4-, 43-, 5- and 4-fold higher urinary concentrations of Cd, Co, Pb and U, respectively. This first biomonitoring study of metal exposure in the African Copperbelt reveals a substantial exposure to several metals, especially in children. The urinary Co concentrations found in this population are the highest ever reported for a general population. The pathways of exposure and health significance of these findings need to be further investigated.