R5 PM Avian Sentinels of Environmental Contamination
Thursday, 17 November 2005: 1:50 PM - 5:30 PM in 321-323

(LET-1117-817210) Dachtal Isomers and Acidic Herbicides and Pesticides in Eggs of Osprey (Pandion haliaetus) From the Duwamish-Lake Washington Area of the U.S. Pacific Northwest.

Chu, S.¹, Henny, C.², Kaiser, J.², Drouillard, K.¹, Haffner, G.¹, Letcher, R.^{1, 3}, ¹ University of Windsor, Great Lakes Institute for Environmental Research, Windsor, Ontario, Canada² Biological Resources Division, Forest and Rangeland Ecosystem Science Center, Corvallis, Oregon, U.S.A.³ Environment Canada, Canadian Wildlife Service, National Wildlife Research Centre, Ottawa, Ontario, Canada

ABSTRACT- A number of current-use, acidic herbicides and pesticides (CUPHs) including MCPP, 2,4-D, 2,4-DB, 2,4,5-T, dicamba, MCPA, triclopyr, the acid metabolites of pyrethroids (3-phenolxybenzoic acid) and dimethyl tetrachloroterephthalate (DCPA or dacthal) were determined in the eggs of osprey (Pandion haliaetus) that were collected during the spring of 2003 from 15 nest sites located in four different areas, the Duwamish-Lake Washington, Lake Washington and Elliott Bay areas in the vicinity of Seattle, Washington, U.S.A., and north of Seattle in the Everett Harbour area. DCPA has proven to be difficult determine in biological matrices. Using existing methods, it is impossible to determine DCPA because it is not readily hydrolyzed to free acid, which is the common form of many other CUPHs. Thus, we developed a new analysis method for the determination of acidic CUPHs, and also DCPA, in osprey egg homogenates. Egg homogenates were extracted with hexane/ acetone, subjected to gel permeation chromatography and HPLC-Si SPE, and the CUPHs were determined by GC-MS(EI) or GC-MS(NCI). The method sensitivity was generally at the low pg/g (wet weight) levels. Average recoveries from spiked eggs was 92%. Of the 12 CUPHs analyzed in osprey eggs (n=15) only DCPA could be quantified (2 - 10 pg/g ww). An unexpected compound was found in all of the egg samples, and confirmed to be the DCPA isomer, dimethyl tetrachlorophthalate (diMe-TCP) (7 - 86 pg/g ww). To our knowledge this is the first report of DCPA isomers in an environmental sample. As diMe-TCP is not an industrial product, and not commercial available, the source of diMe-TCP is unclear. The possible source may be tetrachlorophthalic anhydride (TCPA), which is primarily used as a flame retardant in plastics. Our findings show that DCPA, diMe-TCP and perhaps other isomers are accumulated in the food chain of osprey from study areas in the vicinity of Seattle, and transferred in ovo to eggs, and thus may be of concern to the health of the developing chick and the reproductive health of these osprey populations.

Key words: dachtal isomers, acidic herbicides and pesticides, osprey/eggs, U.S. Pacific northwest