Monitoring of Urinary MTBE, ETBE, TAME and BTEX Biomarkers in Subjects with Non-Occupational Exposure: 2013

Air pollution in major cities is one of the most important concerns of the society. BTEX compounds; benzene, toluene, ethyl benzene, and xylenes are categorized as monocyclic aromatic chemicals. MTBE, ETBE and TAME are oxygenated compounds belonging to the class of ethers. All of these compounds are mainly added to gasoline to enhance octane rate, reduce carbon monoxide emission and improve combustion process as an alternatives to alkyl-lead compounds. The aim of this study was to determine concentrations of urinary biomarkers of mentioned chemicals in subjects with no occupational exposure history. This is a cross-sectional study conducted in 2013. Spot urine samples were collected from 30 healthy volunteers (18 from indoor and 12 from outdoor environments). Head space solid phase micro extraction (HS-SPME) technique was used to extract compounds and a gas chromatograph equipped with FID detector for sample analysis. The mean concentrations of urinary biomarkers of benzene, toluene, ethyl benzene, p+m-xylene, o-xylene, MTBE, ETBE, TAME were respectively 81, 87, 31, 198, 44, 184, 31 and 0 ng/L. No significant difference (p>0.05) was observed in concentrations of urine biomarkers between two groups. According to the results of this and other studies, biomarkers are useful criteria for assessing human exposure to environmental pollutants.