연료첨가제 MTBE의 위해성 및 관리필요성에 관한 연구

Abstract

This study aims to investigate whether it is necessary to regulate MTBE in Korea. MTBE, a gasoline additive, has been a controversial compound worldwide due to contamination of soil and groundwater. In this study, the following materials and information were used: i) available information on MTBE, ii) four articles presented at a seminar held as part of this study (i.e., A study on MTBE risk, MTBE contamination in the soil and groundwater in Korea, Current state and prospect of MTBE use as an additive in gasoline, and Regulations on oxygenates such as MTBE in the U.S. and European countries), and iii) the opinions of the seminar attendants. The use of MTBE has become a worldwide issue due to its potential risk, unpleasant odor and ability to negatively affect the taste of water even at extremely low concentrations, high mobility in soil and groundwater, and low biodegradability. Although the risk of MTBE to human health has not yet been confirmed, some health risk analyses conducted for animals have shown evidence of carcinogenicity, reproductive toxicity, and endocrine disrupting activity of MTBE. Since MTBE dissolves easily in water and does not cling to soil well, it migrates faster and farther in the subsurface than other gasoline components. Remediation of soil and groundwater contaminated with MTBE is a challenge due to its very low biodegradability. Countries have adopted different actions to manage MTBE. In the U.S., where more than 50% of drinking water is supplied from groundwater, MTBE will be banned in 14 states including California and New York. The US EPA placed MTBE on the Contaminant Candidate List in 1999; since then they have continued to investigate the potential health risks and occurrence of MTBE in the U.S.. Based on the results obtained during this investigation, the US EPA is supposed to set federal health standards for MTBE around 2010. On the other hand, MTBE has not been regulated in Europe or Japan, although its use has also been a controversial issue in these countries. In Korea, MTBE has been in continuous demand since the use of unleaded gasoline became mandatory. MTBE is added to gasoline by 6.6-11.6 vol% as of 2001 and is believed to contribute to the abatement of air pollution. However, there has been evidence of MTBE contamination in Korean soil and groundwater. Very high concentrations of MTBE have been observed in the soil and groundwater at five gasoline-contaminated sites in Korea, probably due to the corrosion of underground storage tanks (USTs) and pipelines. The MTBE concentrations of the groundwater were 100 to 1000 times higher than the U. S. drinking water standard. Discussing a ban on MTBE use in Korea seems to be premature at this point, considering the following: i) the incomplete data on the risk of MTBE to human health, ii) various perspectives on MTBE management in different countries, iii) the limited data on MTBE contamination of the soil and groundwater in Korea, and iv) the opinions suggested by experts and the seminar attendants. A risk of MTBE has not been clearly defined, and the effect of the MTBE addition to gasoline on the air quality has not been elucidated, either. Furthermore, the nature, extent, and environmental impacts of MTBE contamination in the soil and groundwater in Korea have not been delineated. Therefore, it would be appropriate at this point to make an effort to reduce the release and potential risk of MTBE to the environment, rather than to ban MTBE use. At present, placing MTBE on the contaminants list under the soil environment protection law and safe drinking water law of Korea is recommended. Future considerations on MTBE are described below. First, investigations on the nature and extent of the soil and groundwater contamination by MTBE should be performed. Second, USTs need to be properly operated and maintained, to reduce the potential risks of MTBE to human health and the environment. Third, sites contaminated with MTBE need to be cleaned up in order to protect soil and groundwater resources. Fourth, efforts should be made to develop alternatives to MTBE or gasoline.