Abstract
Before the permanent introduction of biofuel, ethyl-tert-butyl ether (ETBE) in 2010, we assessed human health risk of ETBE via inhalatory route. The atmospheric emissions from refineries, oil tanks and fuel tanks of vehicles were estimated based on existing emission data on gasoline components and statistical data on vehicles. Based on the estimated emission, the spatial distribution of atmospheric concentrations of ETBE in Japan was estimated by using an atmospheric model at a 5 km × 5 km spatial resolution. In parallel with the exposure assessment, non-observed adverse effect level was determined from results of 13 weeks inhalation toxicity study. Human health risk due to inhalation of ETBE was characterized by comparing margin of exposure (MOE) with a product of uncertainty factors. The result shows human health risk of ETBE via inhalatory route is not at a level of concern.
