Birth Outcomes Associated with Maternal and Fetal Exposure to Metals from Informal Electronic Waste Recycing in Guiyu, China

Abstract

Informal electronic waste (e-waste) recycling is a rapidly growing industry in developing countries, as ~50 million metric tons of e-waste are generated annually. Informal e-waste recycling creates widespread environmental contamination of a mixture of chemicals. The E-waste Recycling Exposure and Community Health (e-REACH) study enrolled pregnant women in Guiyu, an informal e-waste recycling site (n=314), and Haojiang, an unexposed control site, (n=320) at delivery. We analyzed maternal blood, cord blood, and maternal urine for lead (Pb), cadmium (Cd), chromium (Cr), and manganese (Mn). We also captured data in newborns on birth weight, birth length, head circumference, body mass index (BMI), and Ponderal Index (PI). We calculated the geometric mean (GM) for each metal and calculated the ratio between sites using generalized linear models. We ran linear regression models to compare the birth outcomes between sites after adjusting for maternal age, education, occupation, BMI, gravidity, exposure to environmental tobacco smoke, and newborn sex. Maternal blood Pb, Cd, and Cr were higher in Guiyu compared to Haojiang, with a GM of Pb at 6.66 µg/dL (range: 1.87 – 27.09 µg/dL) and was 1.74-fold greater than in Haojiang (95% CI: 1.60, 1.89). Pb in cord blood was 1.53-fold higher in Guiyu (95% CI: 1.38, 1.68). Urinary Cd (2.15, 95% CI:1.72, 2.69), Cr (1.63, 95% CI: 1.09, 2.45), and Mn (2.04, 95% CI: 2.04, 3.31) were also significantly higher in Guiyu compared to Haojiang. Guiyu neonates had significantly smaller head circumference (β: -1.58 cm, 95% CI: -2.03, -1.13), BMI (β: -0.75, 95% CI: -1.11, -0.38), and PI (β: -1.91 kg/m3, 95% CI: -2.98, -0.84). Birth weights were also lower in Guiyu (β:-41.98 g, 95% CI: -135.96, 51.9). We observed differences in the head size and Ponderal Index of neonates from Guiyu when compared to neonates from Haojiang. Since e-waste exposure is a complex mixture, the outcomes could be related to additional chemicals and interactions.