Toxicity of paraquat to a green alga scenedesmus acutus
Titel:
Toxicity of paraquat to a green alga scenedesmus acutus
Auteur:
Saenz, Maria Elena Accorinti, Juan Tortorelli, Maria del Carmen
Verschenen in:
Journal of environmental science and health. Part B, Pesticides, food contaminants, and agricultural wastes
Paginering:
Jaargang 28 (1993) nr. 2 pagina's 193-204
Jaar:
1993-04
Inhoud:
An algal toxicity test was conducted to evaluate the toxic effects on a freshwater alga of increasing concentrations of the herbicide paraquat upon growth, chlorophyll and protein content. Paraquat, a widely used herbicide, was found highly toxic to Scenedesmus acutus. Growth pattern, as well as growth rates and generation times exhibited by the cultures exposed up to 0.05 mg Pq/L, was significantly affected. There was a total inhibition growth at 0.8 mg Pq/ L. A stimulatory growth effect was noticed on the cultures exposed to 0.02 mg Pq/L. Statistical analysis revealed that chlorophyll “a” and protein content decreased as the herbicide concentration in the test media was increased. The calculated EC 50 at 96 hs was 0.04 mg Pq/L. The NOEC was 0.02 mg Pq/L. Microscopical examination of cells did not show morphological changes.