Fate and effects of diuron and linuron in field lysimeters

A field experiment was conducted to evaluate the environmental fate of the phenylurea herbicides diuron and linuron. After herbicides application on the agricultural soil the herbicides were investigated in soil, water, and air samples and their bioaccumulation on annelids was also assessed. Soil and water samples were collected at different depths and analysed to determine residual concentrations of herbicides and the presence of their main metabolites, in order to verify their persistence and their leaching capacity. Air volatilization was calculated using the Theoretical Profile Shape method. Lumbricus terrestris and Octolasion cyaneum were used for the bioaccumulation study to evaluate the terrestrial organism potential uptake. The calculated total mass balance showed a great persistence of linuron and diuron in soil of 40% and 55% respectively, a low mobility in soil pore water (less than 0.5 %) and a negligible effect of volatilisation. The main metabolites detected were DFMU and DCA.