Blood concentrations of lead, cadmium, mercury and their association with biomarkers of DNA oxidative damage in preschool children living in an e-waste recycling area

  • Xijin Xu
  • Weitang Liao
  • Yucong Lin
  • Yifeng Dai
  • Zhihua Shi
  • Xia Huo
Original Paper

DOI: 10.1007/s10653-017-9997-3

Cite this article as:
Xu, X., Liao, W., Lin, Y. et al. Environ Geochem Health (2017). doi:10.1007/s10653-017-9997-3
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Abstract

Reactive oxygen species (ROS)-induced DNA damage occurs in heavy metal exposure, but the simultaneous effect on DNA repair is unknown. We investigated the influence of co-exposure of lead (Pb), cadmium (Cd), and mercury (Hg) on 8-hydroxydeoxyguanosine (8-OHdG) and human repair enzyme 8-oxoguanine DNA glycosylase (hOGG1) mRNA levels in exposed children to evaluate the imbalance of DNA damage and repair. Children within the age range of 3–6 years from a primitive electronic waste (e-waste) recycling town were chosen as participants to represent a heavy metal-exposed population. 8-OHdG in the children’s urine was assessed for heavy metal-induced oxidative effects, and the hOGG1 mRNA level in their blood represented the DNA repair ability of the children. Among the children surveyed, 88.14% (104/118) had a blood Pb level >5 μg/dL, 22.03% (26/118) had a blood Cd level >1 μg/dL, and 62.11% (59/95) had a blood Hg level >10 μg/dL. Having an e-waste workshop near the house was a risk factor contributing to high blood Pb (rs = 0.273, p < 0.01), while Cd and Hg exposure could have come from other contaminant sources. Preschool children of fathers who had a college or university education had significantly lower 8-OHdG levels (median 242.76 ng/g creatinine, range 154.62–407.79 ng/g creatinine) than did children of fathers who had less education (p = 0.035). However, we did not observe a significant difference in the mRNA expression levels of hOGG1 between the different variables. Compared with children having low lead exposure (quartile 1), the children with high Pb exposure (quartiles 2, 3, and 4) had significantly higher 8-OHdG levels (βQ2 = 0.362, 95% CI 0.111–0.542; βQ3 = 0.347, 95% CI 0.103–0.531; βQ4 = 0.314, 95% CI 0.087–0.557). Associations between blood Hg levels and 8-OHdG were less apparent. Compared with low levels of blood Hg (quartile 1), elevated blood Hg levels (quartile 2) were associated with higher 8-OHdG levels (βQ2 = 0.236, 95% CI 0.039–0.406). Compared with children having low lead exposure (quartile 1), the children with high Pb exposure (quartiles 2, 3, and 4) had significantly higher 8-OHdG levels.

Keywords

Lead Cadmium Mercury DNA oxidative damage Preschool children 

Funding information

Funder NameGrant NumberFunding Note
Guangdong Science and Technology Planning Project
  • 2013B051000078
Project of International Cooperation and Innovation Platform in Guangdong Universities
  • 2013gjhz0007

Copyright information

© Springer Science+Business Media B.V. 2017

Authors and Affiliations

  • Xijin Xu
    • 1
    • 2
  • Weitang Liao
    • 1
  • Yucong Lin
    • 3
    • 4
  • Yifeng Dai
    • 1
  • Zhihua Shi
    • 1
  • Xia Huo
    • 4
  1. 1.Laboratory of Environmental Medicine and Developmental Toxicology, and Guangdong Provincial Key Laboratory of Infectious Diseases and Molecular ImmunopathologyShantou University Medical CollegeShantouChina
  2. 2.Department of Cell Biology and GeneticsShantou University Medical CollegeShantouChina
  3. 3.Tabor AcademyMarionUSA
  4. 4.School of Environment, Guangzhou Key Laboratory of Environmental Exposure and Health, Guangdong Key Laboratory of Environmental Pollution and HealthJinan UniversityGuangzhouChina

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