Exposure Factors to Toxic Trace Elements among Post-Delivery Mothers Living in the Vicinity of Mining Operating Plants in Lubumbashi

Author(s): Cham LC, Chuy KD, Mwembo TA, Chenge MF, Tamubango H, Kaniki A, Kalenga MK

Background: The environmental pollution contributes to human exposure to TE through direct skin contact with soil, inhalation of wind-blown dust, direct deliberate or unintentional ingestion of soil and ingestion of foods grown on TE-contaminated soils and waters.

Method: A prospective cohort study of mothers and newborns exposed to TE was conducted. Informations on exposure conditions were collected by a questionnaire-based interviews of 378 post-delivery mothers from whom TE (Al, As, Cd, Cr, Ni, and Pb) were tested at the laboratory of the Congolese Control Office of Lubumbashi by ICP-OES in total blood samples.

Results: The pregnant women working in mining plants had four times the risk of having high concentration of Aluminum: RR 3.84(1.697-8.709), and two times for Lead: 2.08 (1.237-3.50) ; The post-delivery mothers who consumed clay (geophagia) had two fold the risk of having high concentration of Nickel: RR2.14 (1.37-3.34) and Chromium :RR 1.57 (1.04-2.39).Those living in the immediate vicinity of welding workshops had four times the risk of having high concentration of Arsenic: RR 3.97 (1.74-9.05) , when the immediate proximity to an artisanal or industrial mining plants increased two fold the risk of having high concentration of Cadmium: RR 1.86 (1.19-2.91).

Conclusion: Among potential exposure factors to trace elements studied in Lubumbashi: geophagia, immediate proximity to mining plants, use of well water for drinking or housework were the most predominant and associated to high concentration of toxic trace element in total blood of the post-delivery mothers. Implementation of preventive measures should consider these factors.