Representative levels of blood lead, mercury, and urinary cadmium in youth: Korean Environmental Health Survey in Children and Adolescents (KorEHS-C), 2012-2014

Abstract

Background: This study examined levels of blood lead and mercury, and urinary cadmium, and associated sociodemographic factors in 3-18 year-old Korean children and adolescents.

Materials and methods: We used the nationally representative Korean Environmental Health Survey in Children and Adolescents data for 2012-2014 and identified 2388 children and adolescents aged 3-18 years. The median and 95th percentile exposure biomarker levels with 95% confidence intervals (CIs) were calculated. Multivariate regression analyses were performed on log transformed exposure biomarker levels adjusted for age, sex, area, household income, and father's education level. The median exposure biomarker levels were compared with data from Germany, the US, and Canada, as well as the levels of Korean children measured at different times.

Results: The median levels of blood lead and mercury, as well as urinary cadmium were 1.23μg/dL, 1.80μg/L, and 0.40μg/L (95% CIs, 1.21-1.25, 1.77-1.83, and 0.39-0.41, respectively). The blood lead levels were significantly higher in boys and younger children (p<0.0001) and children with less educated fathers (p=0.004) after adjusting for covariates. Urinary cadmium level increased with age (p<0.0001). The median levels of blood mercury and urinary cadmium were much higher in Korean children and adolescents than those in their peers in Germany, the US, and Canada. Blood lead levels tended to decrease with increasing age and divergence between the sexes, particularly in the early teen years. Median levels of blood lead and urinary cadmium decreased since 2010.

Conclusion: Sociodemographic factors, including age, sex, and father's education level were associated with environmental exposure to heavy metals in Korean children and adolescents. These biomonitoring data are valuable for ongoing surveillance of environmental exposure in this vulnerable population.

Keywords: Blood lead; Blood mercury; Children and adolescents; National sample; Urinary cadmium.