Assessment of urine tertiary butyl alcohol levels as biological exposure marker for methyl tertiary butyl ether of road toll station workers in Bangkok

Abstract

The aim of this study was to assess the levels of urine Tertiary Butyl Alcohol (TBA)as an index of biological monitoring for exposure to Methyl Tertiary Butyl Ether (MTBE) amongroad toll station workers in Bangkok metropolitan area. The subjects of this study consistedof 35 road toll station workers as study group. The Airborne MTBE was measured throughoutthe work with a VOCs diffusive sampling device (VOC-SD) attached on the breathing zoneof each subject. The urine samples were collected after work. The Airborne MTBE was analyzedby gas chromatography equipped with MS and the urine samples were done by one withheadspace GC-FID. The geometric mean of Airborne MTBE was 21.9 ppb for road toll stationworkers. The geometric mean of urine TBA level, a metabolite of MTBE, was 232.7 μg/l forroad toll station workers. The correlation between MTBE exposure and urine TBA levels was0.233 (p=0.033). From these results, TBA in urine may be used as biological exposure markerfor occupationally exposed workers to MTBE in Bangkok. However, a bigger sample size infuture study may provide stronger significant findings.

Key words: Methyl tertiary-butyl ether (MTBE), Tertiary butyl alcohol (TBA), Road toll stationworkers, Bangkok