Effect of methyl tert-butyl ether in standard tests for mutagenicity and environmental toxicity.

Methyl tert-butyl ether (MTBE) is a synthetic compound that is used as a technological solution to problems created by air pollution from vehicle emissions. An important source of MTBE in the environment is leakage from underground storage tanks at gasoline stations or accidents during gasoline transport. The aim of this study was to evaluate the risk of MTBE leakage for the environment using the Microtox (Vibrio fischeri) toxicity test, Lactuca sativa seed germination test, and Ames bacterial mutagenicity test with Salmonella typhimurium his(-) strains TA98, TA100, YG1041, and YG1042, using both standard plate and preincubation protocols. The result of Microtox expressed as EC(50) was 33 mg (MTBE)/L. The effect of all tested MTBE concentration (0.05, 0.50, and 1.00% v/v) on Lactuca sativa roots elongation was negative and proved its toxicity. The highest tested concentration of MTBE that could be tested in Ames test was 3 mg (MTBE)/plate, because of cytotoxicity. No mutagenic response was observed at this or lower concentrations in any of the four strains used.