Evaluation of risk for human health and microbial degradation rate of mineral oil components in contaminated soil

After the effectuation of the Soil Contamination Countermeasures Law, a lot of contaminated sites have been found all over Japan. Among the sites, contamination with mineral oils is the most frequent contamination. However, the law dose not have any standard value for mineral oils. According to a guideline about the estimation and countermeasure for soil contaminated with mineral oils, Ministry of environment Japan has shown, detection of oil contamination should be done by the existence of oil smell and film, so that TPH is a just reference value.<br>Onthe other hands, in western countries, evaluation of contaminated soil has been done based on risk fou human health. The evaluation becaomes a standard for the invocation of action and inhibition for turnning to brownfield. Because mineral oils are complex of hydrocarbons and cotaminated site with mineral oils are often combined with other pollutions, it is very difficult to ebvaluate the risk from the sites. Also mineral oils are weathered and decompsed by microorganisms, so that the evaluation become more difficult.<br> This study evaluated that risk for human health and microbial degradation rate of mineral oil components in contaminated soil experimentally using kerosene or diesel oil contaminated soil. In this study, oil components were separated aliphatic and aromatic hydrocarbons according to number of carbons in order to evaluate risk for human health.