Concentration and loading of several pesticides in water, suspended solids and sediment during ordinary water discharge in Sugao marsh, Ibaraki Prefecture, Japan

Concentrations of esprocarb, thiobencarb, dimethametryn, pretilachlor and simetryn in water, suspended solids and sediment were studied during ordinary water discharge over the course of a year in Sugao marsh, Ibaraki Prefecture, Japan. Periodic changes in pesticide concentrations in water were similar to those in suspended solids. Pesticides were mostly present as dissolved form in water. Namely, the partition ratios of total suspended solids in whole water samples were 0.37–2.5% as the median, and the ratios of pesticide loading as adsorbed form on suspended solids against total pesticide loading were 0.42–4.6%. However, the concentrations of pesticides were higher in fine suspended solids (0.5 to 1.0 μm) than coarse suspended solids (more than 1.0 μm). Fine suspended solids loaded with pesticides were estimated to be 18 to 59% of all suspended solids, indicating their important role as a carrier of pesticides. Moreover, vertical distributions of pesticides in sediment down to a depth of 15 cm were not clearly shown, probably due to the disturbance of sediment at the surface by actual water flow. © Pesticide Science Society of Japan

[1]  T. Kawakami,et al.  Concentration and Distribution of Several Pesticides Applied to Paddy Fields in Water and Sediment, from Sugao Marsh, Japan , 2005, Bulletin of environmental contamination and toxicology.

[2]  Tomohiko Yoshida,et al.  A study on pesticide runoff from paddy fields to a river in rural region--1: field survey of pesticide runoff in the Kozakura River, Japan. , 2004, Water research.

[3]  R. Kretzschmar,et al.  Size distribution of organic matter and associated propiconazole in agricultural runoff material. , 2003, Journal of environmental quality.

[4]  P. Lens,et al.  Effect of high salinity on the fate of methanol during the start-up of thermophilic (55°C) sulfate reducing reactors , 2002 .

[5]  Takuya Okubo,et al.  Concentration and loading of pesticide residues in Lake Biwa basin (Japan). , 2002, Water research.

[6]  K. Urano,et al.  Adsorption equilibriums of principal herbicides on paddy soils in Japan. , 2000, The Science of the total environment.

[7]  K. Kawata,et al.  Distribution of Pesticides and Transformation Products to Particulate Matter in River Water , 1998 .

[8]  W. House,et al.  Micro-organic compounds associated with sediments in the Humber rivers , 1998 .

[9]  A. Kettrup,et al.  Sorption of pesticides in the sediment of the Teufelsweiher pond (Southern Germany). I: Equilibrium assessments, effect of organic carbon content and pH , 1998 .

[10]  A. Kettrup,et al.  Distribution of pesticides in the sediment of the small Teufelsweiher pond (southern Germany) , 1997 .

[11]  T. Tsuda,et al.  Pesticides in Water and Fish from Rivers Flowing into Lake Biwa , 1991, Bulletin of environmental contamination and toxicology.

[12]  S. Matsui,et al.  Run-off of Herbicides from Paddy Fields around the Southern Basin of Lake Biwa. , 1996 .

[13]  Takanobu Inoue,et al.  Estimation on the Runoff Amounts of Pesticides Applied after Transplanting of Rice Plant by Drainage River. , 1992 .