Meeting Abstract

P3.10  Tuesday, Jan. 6  Teratogenic Effects of Ethylene Glycol and 5-methyl-1H-benzotriazole on Zebrafish Central Nervous System Development ROMEO, M.R.*; FURIMSKY, M; Westminster College, Pennsylvania; Westminster College, Pennsylvania romeomr@westminster.edu

More than 50 million liters of aircraft deicer and anti-icer fluids (ADAFs) are used annually in North America. ADAFs contain glycols that serve as freezing point depressants and benzotriazoles that act as corrosion inhibitors. Components of ADAFs are known to make their way into aquatic ecosystems, but they are generally harmless to adult fish; however, very little is known about their effects on developing fish. Therefore, we investigated the specific effects of the ADAF additives ethylene glycol (EG) and benzotriazole (BT) on zebrafish embryos to determine whether these chemicals had a teratogenic effect on fish visual system (VS) development. Eye surface area was measured at 48 hours post-fertilization (hpf) following exposure of zebrafish eggs to different concentrations of EG and BT. Mortality rates with EG treatment alone were relatively low at concentrations less than 2.5% EG, but 100% mortality was observed at 5% EG. In BT-only treatment groups, mortality followed a dose-dependent pattern, with 100% mortality observed at 0.1 mg/ml BT. In terms of ontogenic effects, 2.5% EG severely depressed VS development, leaving the eyes at 50% of their normal surface area at 48 hpf. Measures of eye surface area following BT exposure, however, had a less severe impact on VS development, with eye surface area being decreased by 12% and 16% at BT concentrations of 0.025 mg/ml and 0.05 mg/ml, respectively. Exposure to EG and BT, in combination, suppressed VS development to a greater degree. Thus we conclude that high levels of dissolved ethylene glycol and benzotriazole do affect survival in embryonic zebrafish, and sub-lethal doses do indeed have teratogenic effects that can be detrimental to the overall health of fish populations.