Polycyclic Aromatic Hydrocarbon (PAH) metabolites in maternal urine and risk assessment for neonatal birth outcomes in an intensive e-waste recycling area

Polycyclic aromatic hydrocarbons (PAHs) are well-known carcinogenic and endocrine disrupting chemicals whose hydroxylated metabolites have become of increasing concern. We aimed to determine the hydroxylated PAH (OHPAH)... [ view full abstract ]

Polycyclic aromatic hydrocarbons (PAHs) are well-known carcinogenic and endocrine disrupting chemicals whose hydroxylated metabolites have become of increasing concern. We aimed to determine the hydroxylated PAH (OHPAH) metabolite concentrations in maternal urine and evaluate their risk effects on birth outcomes. Maternal urine samples were collected from the e-waste-contaminated area of Guiyu and the reference area of Haojiang, China. The median ƩOHPAH concentration was 6.87 μg/g creatinine from Guiyu, and 3.90 μg/g creatinine from Haojiang. Principal component analysis showed that 2-OHNap and 1-OHPyr were the predominant compounds, followed by 1+9-OHPhe, 2+3-OHPhe and ƩOHPhe. Residence in Guiyu and recycling in houses were associated with predominated PAHs. Risk assessment revealed that high exposure (fourth quartile) to PAH metabolites adversely affected birth outcomes (overall standardized mean difference (SMD): - 0.09; 95%CI: -0.15, -0.03), including head circumference, BMI and Apgar 1 scores, and positively affected height. Quantile linear regression models further demonstrated an inverse association of birth weight (β: -234.56; 95%CI: -452.00, -17.13), head circumference (β: -1.72; 95%CI: -2.96, -0.48) and BMI (β:-1.06; 95%CI: -1.82, -0.31) with the fourth quartile of ƩOHPAHs, and Apgar 1 scores (β: -0.42; 95%CI: -0.66, -0.18) with the third quartile of ƩOHPAHs, after adjusting for confounders. These findings suggest that comparatively high exposure to PAH metabolites during pregnancy in e-waste areas poses a potential detriment to neonatal development, which likely can be attributed to direct e-waste recycling activities. Ongoing studies should be continued to monitor human exposure and health, in particular for vulnerable individuals in e-waste-polluted areas.