Abstract-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 ϭ 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.

Environment Canada has developed a new 42-d sediment toxicity test method that includes a reproduction test endpoint with the freshwater amphipod Hyalella azteca. Because of concerns that existing standard methodologies, whereby adults are transferred to a water-only exposure before release of their first brood at day 28, will lead to internal contaminant depuration and loss of sensitivity, the Environment Canada methodology conducts the entire exposure in sediment. To demonstrate applicability of the method for assessing the toxicity of chemical-spiked sediment, H. azteca were exposed for 42 d to sediment amended with silver nitrate (AgNO ). Mortality was significantly higher at the highest sediment concentration of Ag (2088 mg/kg dry wt); however, there was no significant reduction in biomass or reproduction as a result of Ag exposure despite significant bioaccumulation. Based on Ag measurements and speciation modeling, the principle route of Ag exposure was likely through the ingestion of complexed colloidal or particulate Ag. The techniques used to recover young amphipods from sediment were critical, and although this effort can be labor intensive (20-45 min/replicate), the technicians demonstrated 91% recovery in blind trials. For the first time, Environment Canada will require laboratories to report their recovery proficiency for the 42-d test-without this information, data will not be accepted. Overall, the reproduction test will be more applicable when only a few chemical concentrations need to be evaluated in laboratory-amended sediments or for field-collected contaminated site assessments (i.e., contaminated site vs reference site comparisons). Environ Toxicol Chem 2016;35:2430-2438. © 2016 SETAC.

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.

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Evaluation of Toxicity Reduction Evaluation (TRE) and Toxicity Identification Evaluation (TIE) Application to the Canadian Mining Industry The Aquatic Effects Technology Evaluation (AETE) program was established to review appropriate technologies for assessing the impacts of mine effluents on the aquatic environment. AETE is a cooperative program between the Canadian mining industry, several federal government departments and a number of provincial governments; it is coordinated by the Canada Centre for Mineral and Energy Technology (CANMET). The program was designed to be of direct benefit to the industry, and to government. Through technical and field evaluations, it identified cost-effective technologies to meet environmental monitoring requirements. The program included three main areas: acute and sublethal toxicity testing, biological monitoring in receiving waters, and water and sediment monitoring. The technical evaluations were conducted to document certain tools selected by AETE members, and to provide the rationale for doing a field evaluation of the tools or provide specific guidance on field application of a method. In some cases, the technical evaluations included a go/no go recommendation that AETE takes into consideration before a field evaluation of a given method is conducted. The technical evaluations are published although they do not necessarily reflect the views of the participants in the AETE Program. The technical evaluations should be considered as working documents rather than comprehensive literature reviews. The purpose of the technical evaluations focussed on specific monitoring tools. AETE committee members would like to stress that no one single tool can provide all the information required for a full understanding of environmental effects in the aquatic environment. For more information on the monitoring techniques, the results from their field application and the final recommendations from the program, please consult the AETE Synthesis Report to be published in February 1999.