Biological Trace Element Research

, Volume 153, Issue 1–3, pp 145–154 | Cite as

Mercury (Hg) Exposure in Breast-Fed Infants and Their Mothers and the Evidence of Oxidative Stress

  • Iman Al-Saleh
  • Mai Abduljabbar
  • Reem Al-Rouqi
  • Rola Elkhatib
  • Ammar Alshabbaheen
  • Neptune Shinwari


The objective of this work was to assess exposure to mercury (Hg) and its induction of oxidative stress in 155 healthy lactating Saudi mothers and their infants. Samples of breast milk and blood were collected from the mothers, while urine was taken from both infants and mothers. Both urinary 8-hydroxy-2′-deoxyguanosine (8-OHdG) and malondialdehyde (MDA) were measured in mothers and infants as biomarkers of oxidative stress. The mean concentration of Hg in breast milk was 1.19 μg/L (range 0.012–6.44 μg/L) with only one mother having Hg >4 μg/L, the upper limit established by the US Agency for Toxic Substance and Disease Registry. However, 57.4 % had Hg ≥1 μg/L, the background level for Hg in human milk. The mean urinary Hg corrected for creatinine (Hg-C) in mothers and infants was 1.47 and 7.90 μg/g creatinine, respectively, with a significant correlation between the two (p < 0.001). Urinary Hg levels over 5 μg/g creatinine (the background level in an unexposed population) were found in 3.3 % of mothers and 50.1 % of infants. None of the mothers had total blood Hg above the US Environmental Protection Agency’s maximum reference dose of 5.8 μg/L. No correlation was noted between urinary Hg in infants and Hg in breast milk (p > 0.05). Hg in breast milk, though, was associated with Hg in blood (p < 0.001), suggesting the efficient transfer of Hg from blood to milk. Hg in the breast milk of mothers and in the urine of infants affected the excretion of urinary MDA and 8-OHdG, respectively, in a dose-related manner. These findings reveal for the first time lactational exposure to Hg-induced oxidative stress in breast-fed infants, which may play a role in pathogenesis, particularly during neurodevelopment. This will also contribute to the debate over the benefits of breast milk versus the adverse effects of exposure to pollutants. Nevertheless, breastfeeding should not be discouraged, but efforts should be made to identify and eliminate the source of Hg exposure in the population.


Mercury (Hg) Lactating women Oxidative stress Breast milk Urine Blood 



The investigators thank King Abdulaziz City for Science and Technology (ARP-29-23) for funding this study. We would like to thank all the women who participated in this study and the staff of primary health-care units in Riyadh.


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Copyright information

© Springer Science+Business Media New York 2013

Authors and Affiliations

  • Iman Al-Saleh
    • 1
  • Mai Abduljabbar
    • 1
  • Reem Al-Rouqi
    • 1
  • Rola Elkhatib
    • 1
  • Ammar Alshabbaheen
    • 1
  • Neptune Shinwari
    • 1
  1. 1.Environmental Health Section, Biological and Medical Research DepartmentKing Faisal Specialist Hospital and Research CentreRiyadhSaudi Arabia

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