Occurrence of Chlorinated Paraffins in Beluga Whales (Delphinapterus leucas) from the St. Lawrence River and Rainbow Trout (Oncorhynchus mykiss) and Carp (Cyprinus carpio) from Lake Ontario

Abstract

Samples of 25 dead beluga whales (Delphinapterus leucas) from the St. Lawrence River estuary, as well as samples of 10 rainbow trout (Oncorhynchus mykiss) and 3 carp (Cyprinus carpio) caught in western Lake Ontario were analyzed for total short- (C10-C13) and medium-(C14-C17) chain chlorinated paraffins (SMCCPs) using gas chromatography-low resolution negative chemical ioniza-tion mass spectrometry (GC-NCI-MS) in the selected ion monitoring mode (SIM). Short- and medium-chain chlorinated paraffins were quantitatively identified using two commercial preparations. SMCCPs were detected in all samples. Results ranged from 1.1 to 59 µg/g wet weight in beluga liver tissue, from 6.4 to 166 µg/g wet weight in beluga blubber, and from 0.41 to 9.7 µg/g wet weight in the two freshwater species. The beluga results are higher than those reported for marine mammals in Europe. Total short- and medium-chain chlorinated paraffin levels in the beluga blubber are comparable to previous ∑PCB and ∑DDT results for the same population of beluga whales. The mean ∑SMC-CP concentration in the carp was 0.90 µg/g wet weight and 2.7 µg/g wet weight in the rainbow trout. Results from the freshwater species are comparable to those reported for fish sampled from other industrially impacted waterways in North America but are elevated relative to marine species from European studies. Comparison of the SIM GC-NCI-MS data with results of gas chromatogra-phy-high resolution negative ion mass spectrometry (GC-HR-NIMS) analysis from another study showed that the two analytical techniques are not congruent. The differences may be due to the effects of coeluting interfering organochlorine substances.