석유계총탄화수소의 위해성평가 시 적정 분획 시료수 결정에 대한 고찰

Abstract

In this study, a reliable number of soil samples for TPH fractionation was investigated in order to perform risk assessment. TPH was fractionated into volatile petroleum hydrocarbons (VPH) with three subgroups and extractable petroleumhydrocarbons (EPH) with four subgroups. At the study site, concentrations of each fraction were determined at 18sampling points, and the 95% upper confidence limit (UCL) value was used as an exposure concentration of each fraction. And then, 5 sampling points were randomly selected out of the 18 points, and an exposure concentration was calculated. This process was repeated 30 times, and the results were compared statistically. Exposure concentrations of EPH obtainedfrom 18 points were 99.9, 339.1, 27.3, and 85.9 mg/kg for aliphatic C9-C18, C19-C36, C37-C40, and aromatic C11-C22,respectively. The corresponding exposure concentrations obtained from 5 points were 139.8, 462.8, 35.1 and 119.4 mg/kg,which were significantly higher than those from 18 points results (p <0.05). Our results suggest that limited number ofsamples for TPH fractionation may bias estimation of exposure concentration of TPH fractions. Also, it is recommendedthat more than 30 samples need to be analyzed for TPH fractionation in performing risk assessment.