The assessment of episodic metal pollution. I. Uses and limitations of tissue contaminant analysis in rainbow trout (Oncorhynchus mykiss) after short waterborne exposure to cadmium or copper.

Rainbow trout were exposed to 8 h episodes of either Cd (0.1 or 0.2 mg/L) or Cu (0.1 or 0.6 mg/L) at pH 7. Gill, liver, mucus, blood, skin, muscle, and body remainder were examined for metal content during and after exposure. Accumulation of Cd occurred mostly in the gill, liver, mucus, and muscle, with the gill supporting 21-36% of the body burden. Copper appeared primarily in the gill, liver and mucus, with the gill supporting 4-40% of the body burden. After exposure, rapid clearance of toxicant from the gill and mucus occurred within 16 h, while contamination in the liver increased, resulting in the liver supporting 11-14% or 58-61% of the Cd or Cu body burdens respectively 24 h after exposure. The time of sampling after exposure as well as choice of organs and control data are important aspects of post-exposure analysis. In the absence of control data, exposure status may be derived from the ratio of contaminants in the gill/liver and the distribution of the body burden.