A novel total petroleum hydrocarbon fractionation strategy for human health risk assessment for petroleum hydrocarbon-contaminated site management.

Human health risk assessments for petroleum, oil, and lubricant (POL)-contaminated sites are more complicated than for sites contaminated by single compounds due to the complex composition and various analytical methods associated with total petroleum hydrocarbons (TPH). Although several TPH fractionation methods are commonly used, including that of the TPH Criteria Working Group (TPHCWG), an efficient and economical human health risk assessment method is not yet available. To address this concern, a new modified fractionation strategy is recommended in this study, which resolves the problems of the current TPH fractionation methods while retaining reliability in the results. For the purpose of this study, the distribution characteristics of the 13 TPHCWG fractions were examined, and human health risk assessments for the POL-contaminated sites were performed. The results show that aliphatic EC8-16 and aromatic EC10-21 among the 13 TPH fractions are major contributors to human health risks along all exposure routes, making up approximately 96% of the hazard index (HI) of the TPH fractions, on average. Therefore, it is reasonable to concentrate on aliphatic EC8-16 and aromatic EC10-21 fractions, rather than to study all of the TPH fractions, in evaluating human health risk for TPH-contaminated sites.