Organophosphate ester exposure among Chinese waste incinerator workers: Urinary levels, risk assessment and associations with oxidative stress br

Organophosphate esters (OPEs), which are frequently used as flame retardants and plasticizers in versatile products, are readily released to the external environment. Although workers at municipal waste incineration plants may be ex-tensively exposed to OPEs, only scarce health monitoring and risk assessments have been conducted in this population.In this study, we investigated the levels of eight metabolites of organophosphate esters (mOPEs) and the oxidativestress marker 8-hydroxy-2-deoxyguanosine (8-OHdG) in urine samples from 73 waste incinerator workers and 97 gen-eral residents from Shenzhen, China between September 2016 and June 2017. The overall detection rate of mOPEswas 82.2 %-100 %, and higher concentrations of di-p-cresyl phosphate and chlorinated mOPEs [bis(2-chloroethyl)phosphate (BCEP), bis(1-chloro-2propyl) phosphate (BCIPP), bis(1,3-dichloro-2-propyl) phosphate) (BDCIPP)] werefound among incinerator workers than among general residents. The incinerator workers also showed significantlyhigher levels of 8-OHdG than general residents, but the measured levels of most mOPEs were not significantly corre-lated with the level of 8-OHdG; this may be because co-exposure to multiple toxic compounds can lead to oxidativestress. Risk assessment using Monte Carlo simulations revealed that 95 % of the incinerator workers were free fromnon-carcinogenic effects due to OPEs exposure (hazard index = 0.27, 95 % CI: 0.09, 0.77). However, the carcinogenicrisk of tris(2-chloroethyl) phosphate (TCEP) for incinerator workers was between 10-6and 10-4.Theseresultsindi-cate that incinerator workers are extensively exposed to OPEs, and better protective measures need to be implemented

Automated summary

This study found that waste incinerator workers are more extensively exposed to organophosphate esters (OPEs) and oxidative stress markers than general residents. The concentrations of certain OPEs and oxidative stress markers in urine were higher among incinerator workers. However, the levels of OPEs did not have a significant correlation with the levels of oxidative stress markers. The risk assessment showed that incinerator workers were at a low risk of non-carcinogenic effects due to OPEs exposure, but had a higher risk of carcinogenic effects from tris(2-chloroethyl) phosphate (TCEP).