Epsilon Archive for Student Projects

Abstract

In the present study effects of for functionally different pesticides (a herbicide; isoproturon, a fungicide; captan and two insecticides; deltamethrin and pirimicarb) on sediment microbiota were investigated in two laboratory microcosm studies. The objective of the study was to examine if the pesticides at negligible concentration (NC), maximal permissible concentration (MPC) and a hundred times the maximal permissible concentration (100xMPC) affected microbial respiration, ATP content and bacterial activity in an artificial and in a natural sediment. The NC and MPC were extracted from a recent RIVM report (National institute of public health and the environment, The Netherlands) The results indicated that the tested concentrations had inconsistent effect on the tested biological parameters measured in this experiment. In the experiment with artificial sediment it was found that the isoproturon treatment had an overall effect on community respiration (Twoway ANOVA, P = 0.0106) and that captan had an overall significant effect. Deltamethrin and pirimicarb had no effect on community respiration. Pirimicarb was the only tested pesticide that had an general effect on sediment ATP concentration. The tested pesticides had no effect on bacterial activity. In the experiment with natural sediment no significant effect of the pesticides was found on community respiration. Of the tested pesticides only deltamethrin had an general effect on the ATP concentration. Since no general effect on community respiration or ATP concentration were found no clear-cut conclusions regarding the environmental consequences using the chosen pesticides could be drawn. Accordingly, further studies are needed to evaluate effects at the species level, the community level and the ecosystem level.