N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine quinone (6PPDQ) and its parent 6PPD are ubiquitous in the environment and may induce multi-endpoint toxicity. Electronic waste (e-waste) dismantling is an under-recognized source of 6PPD and 6PPDQ emissions, and there is a lack of epidemiological investigations into their presence and health effects in local populations. This study aimed to determine the urinary concentrations of 6PPD and 6PPDQ in children aged 2-7 years from e-waste dismantling areas and evaluate their potential risk to physical growth. We found that children from the e-waste area had significantly elevated urinary concentrations of 6PPD and 6PPDQ (median: 0.073 and 2.34 ng/mL) compared to those in the reference area (0.020 and 0.24 ng/mL, respectively). The estimated urinary excretions of 6PPDQ in the e-waste exposure group were considerably higher than that in the reference group (p < 0.001). Furthermore, a borderline significant association of co-exposure to high levels of 6PPD and 6PPDQ with lower BMI z-score (OR = 1.99, 95% Cl: 1.04, 3.82) was observed in the crude model and the model adjusted for age and gender. In conclusion, our study first reported the urinary 6PPD and 6PPDQ concentrations in children from e-waste dismantling areas. The result indicated that e-waste recycling activities contribute to significantly elevated body burdens of 6PPD and 6PPDQ in children, which may be a potential risk factor for physical growth. Further epidemiological and toxicological studies are needed to investigate the exposure and health risks, especially in vulnerable populations.
Keywords: 6PPDQ; Biomonitoring; Childhood; E-waste; Physical growth.
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