Trace Metal Exposure and Health Effects among Urban Children Living in Areas with Different Degrees of Pollution in Lubumbashi, DR Congo

摘要

Lubumbashi is the capital city of the (former) Katanga province in DR Congo and hosts many copper-cobalt mines and refining plants that are past and current sources of pollution. We investigated trace metal exposure and possible respiratory health effects among children living in two urban neighbourhoods with different degrees of pollution. During two campaigns conducted in August 2012 (dry season) and January 2013 (rainy season), we recruited children (9-13 y) in Tshamilemba, close to a metal refinery (n=199), and in Maramba, taken as a control area (n=170). We administered a respiratory questionnaire, gave diaries for recording symptoms during two weeks, and performed spirometry. Concentrations of 25 trace metals were measured by inductive coupled plasma - mass spectrometry in spot samples of urine. Metals were also measured in local well waters. Airborne particulate matter (PM10) was collected by static air sampling pumps. Mean PM10 was 121 μg/m3 and 103 μg/m3 in Tshamilemba and Maramba, respectively. Geometric mean (GM, with IQR) concentrations (μg/L) of cobalt in well water were 10-fold higher in Tshamilemba [8 (0.1-2632] than Maramba [0.8 (0.1-3.9)]. GM (IQR) urinary concentrations (μg/g creatinine) of cobalt were higher in Tshamilemba [dry season 16.5 (6.9-29.0); rainy season 20.2 (10.3-33.0)] than Maramba [4.1 (1.8-9.8); 11.9 (5.0-20.1)]. Prevalence of cough during the two weeks of observation was higher in Tshamilemba (13%) than in Maramba (1%), but other symptoms (eyes, skin, wheezing, dyspnea) did not differ. The groups did not differ significantly in pulmonary function indices. In this cross-sectional study, we found evidence of higher exposure to trace metals, especially cobalt, in Tshamilemba than Maramba, but apart from a higher prevalence of cough in Tshamilemba, no other differences in respiratory health were found between the more highly exposed children and the control children.