The impact of pesticides toward parrotfeather when applied at the predicted environmental concentration.

Pesticides pose a serious risk for aquatic macrophytes in the environment. They are also detrimental to the rooted macrophytes used in bioassays for assessment. Currently, no data is available for impact of pesticides toward parrotfeather when present at the predicted environmental concentration. The calculated expected environmental concentration was applied to the plants and the effect was compared. Eight of the 18 pesticides showed significantly different impact. All of the other tested pesticides induced a significant change in pigment content of parrotfeather. The RQ values for risk quotient had a value higher than 0.5, so need regulatory action for environment. This study may be the first to evaluate the predicted environmental concentrations reported by pesticide registration in Europe. Additional studies are required to test all pesticides within one group since the compounds tested may depict a wide toxicity level. Furthermore, the tests should include more than one macrophyte, e.g. one rooted and one non-rooted species, in order to provide a better understanding on pesticide toxicity.