Abstract
The aim of this study was to assess the impact of terbuthylazine in surface waters on fish under experimental conditions. Subchronic toxic effects on embryos and larvae of common carp (Cyprinus carpio) were investigated during a 30-day toxicity test. The exposure to terbuthylazin showed no effect on mortality, but significant differences (P < 0.0001) were revealed on weight and growth parameters at concentrations of 520 and 820 μg/L. The inhibition of specific growth rate at concentrations of 520 and 820 μg/L was 14% compared to the control group. No significant negative effects on total body length and body weight were observed at lower concentrations (0.9 and 160 μg/L). The concentrations 520 and 820 μg/L were associated with a delay in development compared to other experimental groups and controls. On the basis of weight and growth rate evaluation and determination of developmental stages, the No Observed Effect Concentration (NOEC) of terbuthylazine was estimated at 160 μg/L and the Lowest Observed Effect Concentration (LOEC) was 520 μg/L. According to these results, the reported environmental concentration of terbuthylazine in Czech rivers does not impact growth, development, morphology, or histology of carp embryos and larvae.
Highlights
Terbuthylazinee (N2-tert-butyl-6-chloro-N4-ethyl-1,3,5triazine-2,4-diamine), a triazine herbicide, is a selective systemic herbicide which acts as a photosynthesis inhibitor
During the 30 day exposure of embryolarval developmental stages of carp to low concentrations of terbuthylazine (0.9, 160, 520, and 820 μg/L), no effects on mortality of the exposed group compared to controls were found
The effect of terbuthylazine exposure was observable on length and weight growth
Summary
Terbuthylazinee (N2-tert-butyl-6-chloro-N4-ethyl-1,3,5triazine-2,4-diamine), a triazine herbicide, is a selective systemic herbicide which acts as a photosynthesis inhibitor. It is used as a broad spectrum herbicide in maize, sorghum, vines, citrus, coffee, potatoes, legumes, and forestry [1]. Terbuthylazine is used as a substitute for atrazine, which has been banned in many countries. Terbuthylazine is stable in neutral, weakly acid, and weakly alkaline media. Degradation of terbuthylazine in aquatic environment depends on the presence of sediments and biological activity. The half-life in water at 20◦C is 8 days at pH 1, 86 days at pH 5, >200 days at pH 9, and 12 days at pH 13. In sunlight the half-life is >40 days. Its solubility in water is 8.5 mg/L at 20◦C, and log Kow is 3.04 [2]
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have