Prenatal Exposure to Heavy Metals and Adverse Birth Outcomes: Evidence From an E‐Waste Area in China

Electronic waste that has not been properly treated can lead to environmental contamination including of heavy metals, which can pose risks to human health. Infants, a sensitive group, are highly susceptible to heavy metals exposure. The aim of this study was to investigate the association between prenatal heavy metal exposure and infant birth outcomes in an e‐waste recycling area in China. We analyzed cadmium (Cd), chromium (Cr), manganese (Mn), lead (Pb), copper (Cu), and arsenic (As) concentrations in 102 human milk samples collected 4 weeks after delivery. The results showed that 34.3% of participants for Cr, which exceeds the World Health Organization (WHO) guidelines, as well as the mean exposure of Cr exceeded the WHO guidelines. We collected data on the birth weight (BW) and length of infants and analyzed the association between metal concentration in human milk and birth outcomes using multivariable linear regression. We observed a significant negative association between the Cd concentration in maternal milk and BW in female infants (β = −162.72, 95% CI = −303.16, −22.25). In contrast, heavy metals did not associate with birth outcomes in male infants. In this study, we found that 34.3% of participants in an e‐waste recycling area had a Cr concentration that exceeded WHO guidelines, and there was a significant negative association between prenatal exposure to the Cd and infant BW in females. These results suggest that prenatal exposure to heavy metals in e‐waste recycling areas may lead to adverse birth outcomes, especially for female infants. Plain Language Summary In this study, the concentrations of six heavy metals in human milk samples collected 4 weeks after delivery in one of the two largest e‐waste recycling areas in China, that is, Taizhou, Zhejiang Province, were measured. The effects of prenatal heavy metal exposure on infant birth outcomes were analyzed. The results reveal gender differences in infant birth outcomes. For example, prenatal cadmium exposure decreases the birth weight of female infants but has no effect on male infants. We believe that our study makes a significant contribution to the literature because we provide guidance for future analyses. We suggest that the effects of metal exposure in the e‐waste area on the growth and development of infants must be studied over the long term, particularly for female infants. Key Points 34.3% of participants in an e‐waste recycling area had a Cr concentration that exceeded World H