Exposure assessment of xanthate vulcanization accelerators in human urine

Widespread detection of xanthate vulcanization accelerators (XVAs) in various dust samples underscores the inherent risk of their human exposure. Notably, comprehensive investigations into the presence and concentrations of XVAs in human urine, a medium particularly suited for calculating human exposure, are still lacking. To address this knowledge gap, we conducted a systematic examination of eight XVA homologues in urine specimens obtained from 218 healthy adults residing in urban Taizhou City, China. We found that all targeted XVA compounds were identified in collected human urine samples, with potassium butylxanthate (KBX; mean 32 ng/mL, range < LOD-120 ng/mL) and potassium amylxanthate (KAX; 26 ng/mL, < LOD-91 ng/mL) exhibiting the highest mean urinary levels. Males consistently demonstrated higher mean urinary concentrations of KAX, potassium propylxanthate (KPX), and potassium ethylxanthogenate (KEX) compared with females, though these differences did not reach statistical significance. Notably, age-related decreases in human urinary concentrations were observed for KAX, KBX, and KEX. The highest daily exposure (DE) was recorded for KBX at the average level of 906 ng/kg bw/day, ranging from < 38-3056 ng/kg bw/day. KAX exhibited a mean DE of 718 ng/kg bw/day (< 14 -2048 ng/kg bw/day), while KPX showed a mean DE of 403 ng/kg bw/day (< 26 -213 ng/kg bw/day). As the first comprehensive analysis of XVAs in human urine samples, this research establishes fundamental exposure data essential for evaluating their health implications.