Physiological effects and tissue residues from exposure of leopard frogs to commercial naphthenic acids

► Northern leopard frogs were exposed to two concentrations of commercial (Merichem) NAs under saline conditions for 28 days. ► These laboratory exposures resulted in proportional NAs concentrations in muscle tissue of the frogs. ► Innate immune function, thyroid hormone levels, and hepatic detoxification enzyme induction where not affected by the NAs. ► Exposure to NAs caused a statistically significant increase in frog body weight.