8292079 Urinary chemical burdens and potential health risks among electrioinc-waste recycling workers in Hong Kong

<h3>Introduction</h3> Electronic-waste (e-waste) workers are potentially exposed to Organophosphate esters (OPEs), heavy metals and other chemicals such as, bisphenol A, PFAS, PAH, etc. Nevertheless, no study has evaluated these chemical exposure levels and the related health risks among e-waste workers in Hong Kong. <h3>Objectives</h3> This study aims to assess the urinary chemical levels and their potential health risks among e-waste workers. <h3>Methods</h3> 201 first-spot morning urine samples were collected from 101 e-waste workers and 100 office workers to compare eight urinary OPE metabolites (mOPEs) levels and 21 metals in these groups. Urinary concentration of the oxidative DNA damage marker (8-OHdG) was tested. Spearman’s correlation was used to evaluate the associations between mOPEs (metals components). The associations between individual mOPEs (metals) and 8-OHdG were determined by general linear regression, quantile g-computation (QGC) and Bayesian kernel machine regression (BKMR). <h3>Results</h3> The concentrations of six mOPEs were similar in e-waste workers and office workers, except for significantly higher levels of diphenyl phosphate (DPHP) in e-waste workers and bis(1-chloro-2propyl) phosphate (BCIPP) in office workers. Spearman correlation analysis showed that most non-chlorinated mOPEs were correlated with each other in e-waste workers, indicating that handling e-waste could be the exposure source of specific OPEs. The median values of estimated daily intake (EDI) and hazard quotient (HQ) suggested that the health risks from OPEs exposures were under the recommended thresholds. However, linear regression models, Quantile g–computation, and Bayesian kernel machine regression found that urinary mOPEs elevated 8-hydroxy-2-deoxyguanosine (8-OhdG) levels individually or as a mixture, in which DPHP contributed prominently. <h3>Conclusion</h3> Although e-waste might not elevate the internal OPEs levels among the participating Hong Kong e-waste workers, attention should be paid to the potential DNA damage stimulated by OPEs under the currently recommended thresholds. (Funding: GRF/RGC 14604020), CUHK Ref.:E.C./2017/006, and SSFCRS Ref.:TL/SSFCRS2223/0953/23ww.).