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Oral antimicrobial activity weakened in children with electronic waste lead exposure

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Environmental lead (Pb) exposure can induce dysbacteriosis, impair oral health, and is associated with the development of dental caries. However, the mechanism is unclear. The aim of this study was to explore the effects of Pb toxicity on oral antimicrobial activity in children in an e-waste area. Results showed higher blood Pb levels in e-waste-exposed group children, accompanied by decreased saliva SAG (salivary agglutinin) concentrations, increased peripheral WBC (white blood cell) counts and monocyte counts, and elevated peripheral monocyte percentage. LnPb (natural logarithmic transformation of blood Pb level) was negatively correlated with saliva SAG concentration, while positively correlated with peripheral monocyte percentage. Saliva SAG concentration played a complete mediating role in the correlation of LnPb to peripheral monocyte percentage. To our knowledge, this is the first study on the relationship of environmental Pb exposure and oral antimicrobial activity in children, showing that environmental Pb exposure may weaken oral antimicrobial activity through reducing saliva SAG concentration, which may raise the risk of oral dysbacteriosis and ultimately pathogen infection.

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Fig. 1
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Fig. 3





natural logarithmic transformation of blood Pb level


salivary agglutinin

PM2.5 :

fine particulate matter


persistent organic pollutants


body mass index


antimicrobial protein and peptide


white blood cell


electronic waste


confidence interval


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We acknowledge all the recruited children and their guardians for participating in this project. We also thank Dr. Nick Webber for his constructive comments and English language editing.


This work was supported by the National Natural Science Foundation of China (21876065).

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Correspondence to Xijin Xu.

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Zhang, S., Huo, X., Li, M. et al. Oral antimicrobial activity weakened in children with electronic waste lead exposure. Environ Sci Pollut Res (2020).

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  • Oral antimicrobial activity
  • Children
  • Lead exposure
  • Peripheral monocyte percentage
  • Saliva salivary agglutinin
  • Electronic waste