Accumulation of Thallium in Rainbow Trout (Oncorhynchus mykiss) Following Acute and Subchronic Waterborne Exposure.

This article focuses on the tissue-specific accumulation of the trace metal thallium (Tl) in rainbow trout (Oncorhynchus mykiss) following acute (96-hour) and subchronic (28-day) waterborne exposures. The study found dose-dependent Tl accumulation in gill, plasma, muscle, and otolith tissues at elevated exposure concentrations, while no significant accumulation occurred near the Canadian Council of Ministers for the Environment (CCME) guideline of 0.8 µg L−1. Despite Tl’s mimicry of potassium ions (K+), Tl exposure did not disrupt K+ homeostasis in muscle or plasma. Notably, muscle Tl concentrations at higher exposures exceeded acceptable daily intake values for humans, indicating potential health risks from consuming fish from Tl-contaminated waters, such as those near mining areas. The research also demonstrated that otolith Tl concentrations reflect exposure history, supporting their use in environmental biomonitoring.