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Human hair has been identified as a non-invasive alternative matrix for assessing the human exposure to specific organic contaminants. In the present study, a solvent-saving analytical method for the simultaneous determination of 8 polybrominated diphenyl ethers (PBDEs), 3 hexabromocyclododecanes (HBCDDs), 12 phosphorus flame retardants (PFRs), and 4 emerging PFRs (ePFRs) has been developed and validated for the first time. Hair sample preparation protocols include precleaning with Milli-Q water, digestion with HNO3/H2O2 (1:1, v/v), liquid-liquid extraction with hexane:dichloromethane (4:1, v/v), and fractionation and cleanup on a Florisil cartridge. The method was validated by using two levels of spiked hair samples of 3 replicates for each spiking group. Limits of quantification (LOQs) were 0.12-22.4 ng/g for all analytes, average values of accuracies were ranging between 88 and 115%, 82-117%, 81-128%, and 81-95% for PBDEs, HBCDDs, PFRs, and ePFRs, respectively; and precision was also acceptable (RSD

Urinary metabolites of phosphate flame retardants (PFRs) were determined in workers from an electronic waste (e-waste) recycling site and an incineration plant, in order to assess the PFR exposure risks of workers occupied with e-waste recycling and incineration. Bis(2-chloroethyl) phosphate (BCEP), bis(1,3-dichloro-2-propyl) phosphate (BDCIPP), and diphenyl phosphate (DPHP) were the most frequently detected chemicals (82-93%). The median concentrations of BCEP, BDCIPP, and DPHP were 1.77, 0.23, and 0.70 ng/mL, and 1.44, 0.22, and 0.11 ng/mL in samples from the e-waste site and the incineration plant, respectively. Dibutyl phosphate (DBP) was detected in all samples from the incineration plant, with a median level of 0.30 ng/mL. The concentrations of BDCIPP (r = -0.31, p 0.05) were significantly correlated with the occupational exposure time rather than age in workers from the e-waste site. Negative and significant correlations were also observed between the concentrations of BCEP (r = -0.42, p 0.05), BDCIPP (r = -0.37, p 0.05), and DPHP (r = -0.37, p 0.05) and occupational exposure time rather than age in workers from the incineration plant. No gender differences were observed in levels of PFR metabolites in urine samples (p 0.05). Concentrations of BDCIPP in female were significantly correlated with occupational exposure time (r = -0.507, p 0.01). Concentrations of PFR metabolites in male were not significantly correlated with age or occupational exposure time (p 0.05). Overall, the workers with occupational exposure to PFRs had different profiles of urinary PFR metabolites. The age, occupational exposure time, and gender seemed not to be main factors mediating the exposure to PFRs for workers occupied with e-waste recycling and incineration.

In the present study, urine samples (n = 258) were collected from adults (n = 42) and children (n = 22) in an electronic waste (e-waste) recycling site. The concentrations and compositions of six di-esters, or the metabolites of phosphate flame retardants (PFRs), were measured at different time points on consecutive days. Bis(2-chloroethyl) phosphate (BCEP), dibutyl phosphate (DBP), bis(1,3-dichloro-2-propyl) phosphate (BDCIPP), and diphenyl phosphate (DPHP) were detected in more than 50% of urine samples. The median concentrations of BCEP, DBP, BDCIPP, and DPHP were 2.43-4.80, 0.09-2.65, 0.46-0.89, and 0.66-1.83 ng/mL in adult urine samples, respectively. For children, the median concentrations of BCEP, DBP, BDCIPP, and DPHP were 1.23, 0.08, 0.06, and 0.29 ng/mL in morning urine samples, and 1.86, 0.12, 0.14, and 0.27 ng/mL in nightfall urine samples, respectively. Nightfall urine had generally higher levels of di-esters than those in morning urine for both adults and children (p 0.05). Children had significantly lower concentrations of di-esters than adults, indicating the occupational exposure risks of PFRs for adults. Significant correlations were observed in levels of BDCIPP (3 out of 6 groups of samples) and DPHP (2 out of 6 groups of samples) in couples (p0.05). Significant correlations between parents and boys were only observed in BCEP levels in nightfall urine samples, and in DBP levels in morning urine samples (p0.05). The results suggest that di-ester concentrations in e-waste recycling workers are highly variable depending on the time that samples are collected, which could further influence the estimation of human exposure to PFRs.