title: Combined toxicities of methyl tert-butyl ether and its metabolite tert-butyl alcohol on earthworms via different exposure routes.
abstract: Methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA) are among the major soil contaminants that threaten the health of soil ecosystems. Many MTBE-contaminated sites accumulate TBA, because TBA is the intermediate of MTBE biodegradation. To access the risk of MTBE and TBA in soil, we investigated the combined toxicities of MTBE and TBA using two earthworm species, Perionyx excavatus and Eisenia andrei, as well as the toxic effects via different exposure routes. The combined toxicity showed weak antagonistic effects (LC50mix values were slightly greater than 1.0), and sensitivity toward same pollutants differed in the two earthworm species. Moreover, the toxicity of MTBE and TBA was also affected by the exposure route; both filter paper and artificial soil tests showed that dermal-only exposure to MTBE had an even greater toxic effect than combined dermal and oral exposure. Thus, we suggest that diverse environmental factors including organic materials, the physicochemical properties of the contact media, and the exposure routes of the organism, should be taken into consideration when assessing the effects of pollutants on organisms in diverse environmental systems.
authors.affiliation: Department of Environmental Health Science, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 143-701, Republic of Korea.
authors.forename: Woo-Mi
authors.initials: WM
authors.lastname: Lee
authors.affiliation: Department of Environmental Health Science, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 143-701, Republic of Korea.
authors.forename: Youngdae
authors.initials: Y
authors.lastname: Yoon
authors.affiliation: Department of Environmental Health Science, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 143-701, Republic of Korea. Electronic address: anyjoo@konkuk.ac.kr.
authors.forename: Youn-Joo
authors.initials: YJ
authors.lastname: An
mesh_terms: D000818:Animals; D001673:Biodegradation, Environmental; D004781:Environmental Exposure; D007928:Lethal Dose 50; D008738:Methyl Ethers / Q000633:toxicity*; D009835:Oligochaeta / Q000187:drug effects*; D012989:Soil Pollutants / Q000633:toxicity*; D013045:Species Specificity; D020002:tert-Butyl Alcohol / Q000633:toxicity*
chemical_list: D008738:Methyl Ethers; D012989:Soil Pollutants; C043243:methyl tert-butyl ether; D020002:tert-Butyl Alcohol
keywords: Eisenia andrei; Methyl tert-butyl ether; Perionyx excavatus; Risk assessment; Soil; tert-Butyl alcohol