No association between prenatal lead exposure and neurodevelopment during early childhood in the Japan Environment

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Hirosuke Inoue1, Masafumi Sanefuji2,3, Yuri Sonoda1,4

  • 1Department of Pediatrics, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.

Scientific Reports
|September 12, 2022
PubMed

Insights

Prenatal lead exposure showed no clear link to neurodevelopmental delays in early childhood. This large study found no convincing evidence of harm from low prenatal lead levels on children's development.

Area of Science:

  • Environmental Health
  • Pediatric Neurodevelopment
  • Toxicology

Background:

  • Prenatal lead exposure effects on neurodevelopment are less understood than childhood exposure.
  • Existing research on prenatal lead and neurodevelopmental outcomes remains inconclusive.
  • Investigating early-life lead exposure is crucial for public health interventions.

Purpose of the Study:

  • To examine the association between prenatal blood lead levels and neurodevelopmental delay in children up to three years old.
  • To analyze lead exposure during pregnancy and its impact on early childhood neurodevelopment.
  • To contribute data to the understanding of low-level lead exposure effects.

Main Methods:

  • Prospective cohort study of 80,759 children from the Japan Environment and Children's Study.
  • Maternal blood lead levels measured in the second/third trimesters and cord blood at birth.
  • Neurodevelopment assessed using the Ages and Stages Questionnaires (ASQ) at multiple time points up to 36 months.

Main Results:

  • Geometric mean blood lead concentrations were low (0.62 μg/dL maternal, 0.50 μg/dL cord blood).
  • No significant associations were found between prenatal lead levels and suspected neurodevelopmental delay (sNDD) at 1 and 2 years.
  • A slight inverse association with sNDD at 3 years was observed for maternal lead, but without a clear dose-response relationship.

Conclusions:

  • This large-scale study found no convincing evidence linking prenatal lead exposure to neurodevelopmental delays in early childhood.
  • Current low levels of prenatal lead exposure in the study population do not appear to adversely affect early neurodevelopment.
  • Further research with longitudinal prenatal and postnatal lead measurements is recommended to fully elucidate the relationship between lead exposure and neurocognitive development.

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