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IGCP/SIDA Project 594, Annual Workshop, Windhoek, Namibia, 2012Pathways of exposure to cobalt in populations living in Katanga, D.R. CongoC. Banza Lubaba Nkulu1, K. Cheyns2, J. Ngoy Asosa1, L. Kabamba Ngombe1, A. Mutombo Mwanza1, V. Haufroid3, Th. De Putter4, O. Luboya Numbi1, B. Kabyla Ilunga1, C. Muleka Kimpanga1, B. Nemery5, E. Smolders2 Unité de Toxicologie et Environnement, Ecole de Santé Publique, Université de Lubumbashi, Lubumbashi, D.R. Congo Division of Soil and Water Management,Department of Earth and Environmental Sciences, KU Leuven, Leuven, Belgium Laboratoire de Toxicologie Industrielle et Médecine du Travail, U.C. Louvain, Brussels, Belgium Geology, Royal Museum for Central Africa, Tervuren, Belgium Occupational, Environmental and Insurance Medicine, Department of Public Health, KU Leuven, Leuven, Belgium
“African copperbelt” Kamina 10°0’0’’S Likasi Lubumbashi 12°0’0’’S Kipushi 26°0’0’’E 28°0’0’’E
Background • Evidence of high exposure to several metals (Co, Cu, As, U, …) in the population of south Katanga • Evidence of higher exposure in subjects living very close (< 3 km) to mines or smelting plants
Aims Main pathways of exposure ? • Air • Dust • Water • Diet (staple foods, vegetables, fish, meat, ...) • Work
IGCP/SIDA Project 594, Annual Workshop, Kitwe, Zambia, 2011 • Preliminary data • Concentrations of metals in urine of adults and children • Concentration of metals in environmental samples (drinking water, indoor + outdoor dust, fish, chickens) in three areas (Likasi & Lake Changalele)
Likasi and Lake Changalele AControl • 2 villages : Misisi-Sando(alongriverLufira),Kidimudilo BLikasi • 2 urban areas in vicinity of metallurgicalplants: Q. Shituru, Q. Panda CLake Changalele(receiveseffluentsfrommetallurgicalplants in Likasi): • 3 villages close to Lake Changalele (high fishconsumption): Kansalabwe, Shinangwa, Kibangu
KIBANGU SHITURU KANSALABWE R PANDA PANDA SHINANGWA KIDIMUDILO R. LUFIRA MISISI-SANDO
Street City Country World WikiMapia WikiMapia View View Add place Add place 11036019 places 11036019 places Food Fish Shinangwa 2009
Air pollution Likasi 2006
IGCP/SIDA Project 594, Annual Workshop, Kitwe, Zambia, 2011 Preliminary conclusions Main source of exposure to metals appears to be dust Fish may also be a significant source Contribution of vegetables needs to be assessed
IGCP/SIDA Project 594, Annual Workshop, Windhoek, Namibia, 2012 • Additional data & further analysis re. Co • Concentration of metals in food items (maize flour, locally grown vegetables, ...) • Food questionnaire (quantity/quality) • Additional locations • 1 urban area in Lubumbashi (Q. Kabecha) close to a copper/cobalt processing plant • 1 rural area close to a cobalt mine (Shamitumba) • 2 control locations outside Copperbelt (Kamina, Mbuji-Mayi)
Sampling • Volunteers – convenience sampling (family clusters: adults + children) • Simple questionnaire (age, residence, …) • Food questionnaire (1 per household) • Spot sample of urine (avoiding contamination) • Soil dust samples (outdoor + indoor) • Drinking water • Chickens (liver, kidney) + Fish • Kitchen gardens (soil, vegetables) + maize flour
Analytical methods • Urine • Water • Animal tissues • Vegetables oven dried, acid destruction • Soil & dust • Analysis by ICP-MS (Inductively Coupled Plasma Mass Spectrometry)
Estimation of intake of Co • Dietary intake based on • food questionnaire (average data) • concentrations of Co in collected samples • Dust intake based on • estimate from literature • concentrations of Co in indoor + outdoor dust
Estimated Co intake (µg/day) – Adults 62 65 55 62 99 170 79 635 509 593 553
Estimated Co intake (µg/day) – Children 36 34 29 33 46 34 37 352 416 313 340
Conclusions • Good (but not perfect) relation between estimated Co intake and urinary concentration of Co • Lower bioavailability of Co in dust? • Incorrect estimate of quantity of dust intake? • Main contributory sources of Co: • Control areas: ~90% maize flour + vegetables • Lakeside areas: ~25% fish • Polluted areas: vegetables and dust (dust especially in children) • Further analyses are planned for other metals