Effects of trifluralin on carp: biochemical and histological evaluation.

Acute and subacute toxicity of the herbicide trifluralin on fish was investigated in laboratory toxicity tests with carp. Median lethal concentrations were determined in acute tests. The 96-h LC50 value was 0.045 (0.036-0.051)mg/L. Fish were exposed to subacute concentrations of the herbicide (0.005, 0.01, and 0.02 mg/L trifluralin) in the 14-day toxicity tests and the effects on the relative growth rate, some biochemical parameters [alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanin aminotransferase (ALT) activities in serum, gills, liver, and kidney], gills, liver, and kidney structure were studied. A decrease in relative growth rate was found. An increase of functional enzyme activities in blood serum and the organs examined, particularly in the highest concentration of trifluralin indicated changes in the vital organs, was confirmed by histological analysis. The most severe changes (although mostly reversible) were found in the gills and kidney of the fish examined.