ACUTE TOXICITY OF STORM WATER ASSOCIATED WITH DE-ICING/ANTI-ICING ACTIVITIES AT CANADIAN AIRPORTS.

Environment Canada, Transport Canada, and the Airline Transport Association of Canada recently evaluated the use of toxicity bioassays to assist in managing wastewater from aircraft de-icing at Canadian airports. This study evaluated the effectiveness of a suite of rapid screening bioassays to predict the responses of standard regulatory test organisms to storm water associated with de-icing at four Canadian airports. Storm water samples were tested using two standard acute lethality bioassays (rainbow trout [Oncorhynchus mykiss], Daphnia magna) and four rapid screening bioassays (Daphnia IQ ™, acute Microtox ®, Rotoxkit ®, Thamnotoxkit ®). Environmental samples (runoff water) and concentrated de-icing/anti-icing chemicals from the clean-up vehicles (sweeper trucks) were collected from each airport and tested. Forty percent (n = 10) of the environmental samples were lethal to trout, and 30% were lethal to D. magna. The IQ and Thamnotoxkit test results were comparable to those of the trout and daphnid bioassays, respectively. Disadvantages associated with the IQ and Thamnotoxkit bioassays included the lack of a standardized quality-assurance/quality-control program, subjectivity in endpoint measurements, and problems in cyst hatching. The limited number of storm-related samples did not permit definitive determination for the causality of toxicity. Results suggest that glycol was not predictive of acute lethality, and that other substances likely contributed to toxicity. [ABSTRACT FROM AUTHOR]