PARENT SESSION

PM06 Emerging Pollutants
Exhibit Hall
8:00 AM - Monday

(PM044) Dietary accumulation of hexabromocyclododecane (HBCD) isomers in juvenile rainbow trout (Oncorhynchus mykiss).

Law, K^{1, 2}, Palace, V^{1, 2}, Halldorson, T¹, Danell, R¹, Wautier, K¹, Evans, B¹, Brinkworth, L¹, Alaee, M³, Tomy, G^{1, 2}, ¹ Department of Fisheries and Oceans, Winnipeg, Manitoba, Canada² University of Manitoba, Winnipeg, Manitoba, Canada³ Environment Canada, Burlington, Ontario, Canada

ABSTRACT- Juvenile rainbow trout (Oncorhynchus mykiss) were exposed separetly to the 3 isomers of HBCD via their diet to examine the bioaccumulation parameters [biomagnification factors, depuration rate (k_d) and half-lives (t_1/2)]. Fish in a fourth tank were exposed to control food (i.e., unspiked food). Fish were exposed to HBCD treated food for 56 days, followed by a 112 day depuration phase, where fish in all tanks were fed control food. Fish were sampled on days 0, 7, 14, and 56 of the uptake phase, and days 63, 70, 112, and 168 of the depuration phase and the muscle tissue was analyzed for HBCD by LC/MS/MS. Depuration from the fish followed a first order process; compared to the -isomer, the -isomer showed an initial rapid depuration for the first 7 days of depuration. The analysis of -fed fish is ongoing. The depuration rate, k_d, for the -isomer (0.0196d^-1) was almost two times higher than that of the -isomer (0.0101d^-1). Half-lives (t_1/2 = ln2/k_d) for the - and -isomers were 35.4 days and 68.6 days respectively. These preliminary results suggest that these differences in the half lives of - and -HBCD are likely to play a role in the isomer distribution and dynamics of these compounds in biota. The analysis of muscle tissue during the uptake phase is underway.

Key words: Oncorhynchus mykiss, hexabromocyclododecane, bioaccumulation parameters