Effects of subchronic exposure to simazine on zebrafish (Danio rerio).

Objectives: Simazine is a triazine herbicide which has been used for a long period in agriculture and in the aquatic environment for control of weeds and algae. The aim of this study was to investigate the effects of subchronic exposure to simazine on growth and the development of histopathological changes in selected organs (gills, kidney, liver) in Danio rerio.

Methods: Juvenile growth tests were performed on D. rerio according to the OECD method No. 215. Fish at the age of 20 days were exposed to the environmental simazine concentration commonly detected in Czech rivers (0.06 μg.L-1) and a range of sublethal concentrations of simazine (0.6, 6.0 and 60.0 μg.L-1) for 28 days.

Results: There were no significant differences (p<0.05) between the specific growth rates (r) of the test groups and those of both control groups. Histopathological examination revealed pathological changes in fish exposed to a simazine concentration of 60.0 μg.L-1. The values of NOEC and LOEC of simazine were 6.0 μg.L-1 and 60.0 μg.L-1.

Conclusions: The environmental concentration of simazine in Czech rivers did not have any effects on the growth and development of histopathological changes in D. rerio.