Transplacental transfer of cobalt: Evidence from a study of mothers and their neonates in the African Copperbelt.
J Trace Elem Med Biol 2023;
80:127294. [PMID:
37677922 DOI:
10.1016/j.jtemb.2023.127294]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Revised: 07/29/2023] [Accepted: 08/21/2023] [Indexed: 09/09/2023]
Abstract
BACKGROUND
Transfer of the trace metal cobalt (Co) from mother to foetus has not been documented in populations with high environmental exposure to Co, as is the case in the African Copperbelt mining region. We analysed data obtained from 246 mother-infant pairs included (at delivery) in a previously published case-control study on birth defects, done in Lubumbashi (Democratic Republic of Congo) between March 1, 2013, and Feb 28, 2015.
METHODS
Co was measured by Inductively Coupled Plasma Mass Spectrometry in maternal blood, maternal urine, umbilical cord blood and placental tissue, as available.
RESULTS
The Co concentrations [geometric mean (GM) with interquartile range (IQR)] in maternal blood (GM 1.77 µg/L, IQR 1.07-2.93) and urine (GM 7.42 µg/g creatinine, IQR 4.41-11.0) were highly correlated (Spearman r = 0.71, n = 166; p < 0.001) and considerably higher than reference values determined for general populations elsewhere in the world. The concentrations of Co in umbilical cord blood (GM 2.41 µg/L) were higher (Wilcoxon test, p < 0.001) than in maternal blood (GM 1.37 µg/L), with a correlation between both values (Spearman r = 0.34; n = 127, p < 0.001). Co concentrations in placental tissue (geometric mean 0.02 µg/g wet weight) correlated with concentrations in maternal blood (Spearman r = 0.50, n = 86, p < 0.001) and in neonatal blood (Spearman r = 0.23, n = 83, p = 0.039).
CONCLUSION
This first study of maternal and neonatal Co concentrations in the African Copperbelt provides strong evidence of a high transfer of Co from mother to foetus.
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