Toxic Metallic Trace Elements in Post-Delivery Mothers and their Newborns Residing near and far from Mining Operating Plants in Lubumbashi

Abstract

Background: Worldwide, modern life is characterized by excess of toxicTE due to pollution (domestic and industrial waste) and reduced intake of essential TE, consequence of imbalanced diet. In the context of cases of environmental pollution by TE documented in the city for years, the purpose of this study was to determine blood concentrations of essential TE and correlation coefficients in post-delivery mothers and their newborns living 3km from the mining processing plants in the city of Lubumbashi, Congo. Method: Two prospective cohorts were formed based on distance between the home of the pregnant women and mineral processing plants ( 3km). Four TE (Cr, Cu, Se and Zn) were tested at the laboratory of the Congolese Control Office of Lubumbashi by ICP-OES in total blood samples of 378 post-delivery mothers and 378 newborns, voluntarily and consecutively recruited. Results: The difference in TE geometric means concentrations between the two cohorts (study population living 3km from the mining processing plants) was not significant (p>0.05).Our study showed excessive geometric means of Cr estimated at 4.86 µg/L in the post-delivery mothers and 5.03 µg/L in the newborns (RV: < 1 µg/L ), lower geometric means estimated at 218 µg/L in the post-delivery mothers for Cu ( RV:700-1500 µg/L) ;47.32 µg/L in the post-delivery mothers and 46.61µg/L in the newborns for Se (RV: < 142 µg/L ) ;419 µg/L in the post-delivery mothers and 384 µg/L in the newborns for Zn (RV: < 7270 µg/L ) but within normal range :215 µg/L in the newborns for Cu (RV: 90-460 µg/L).This was confirmed by their respective bioaccumulation factors. The correlation coefficient between TE concentration of the post-delivery mothers and their newborns was positive but statistically significant for Cu, Se and Zn (p<0.05). Conclusion: Our study has noticed low geometric means of the concentrations of Cu, Se and Zn in total blood of post-delivery mothers and their newborns living 3 km from the mining operating plants with no statistical difference between the two cohorts along with bioaccumulation factor <1. We also found excessive geometric mean for Cr. These findings hence the importance of an early diagnosis and intervention of marginal TE status. Analysis of determinants of the essential TE bioaccumulation and their impact on maternal and neonatal morbidity should be purpose of future studies.