Occurrence of antifouling herbicide diuron from Seto Inland Sea, Japan

Abstract

IntroductionThe toxicity and persistence of booster biocides are of major concern. This study reports the occurrence of diuron (3,4-dichlorophenyl-1,1-dimethylurea) biocide in surface off shore waters, surface sediments and plankton samples. Diuron is the Halogenophenylureas form one of the main groups of herbicides used for more than 40 years in fields and antifouling is also a source of pollution in marine environment. This work shows data on the occurrence of diruon in the surface waters, sediments and planktons. To our knowledge, this is first study reporting diuron concentration in planktons in Japan, particularly in Seto Inland Sea.Sample collection, preparation and analysisDiuron in surface sea water, sediment and plankton were measured with respect to the distribution around Hiro bay, Aki Nada, Osaka bay, Harima bay, Kozima bay and Bingo nada sites were surveyed on the Seto Inland Sea in west Japan and samples were collected in the off-shore area at Autumn Cruise (October 20-24, 2008) by research vessel Toshiomaru, Hiroshima University. Seawater sample was collected by Niskin samplers and filtration was done immediately by GF/C filters (0.45 μm) in ship. Diuron compound is extracted from the samples by solid phase extraction (SPE) using C18 sep-pack cartridge column. Sample extracted were analysed by HPLC-UV detection (254 nm). Recovery rate of diuron from SPE was examined and the recovery rate was 95% for distilled water and 88% for sea water. The recovery rate of diuron from sediment was 92% and plankton recovery analysis was not done. Results and discussionConcentration of Diuron in marine samplesranged from 30 to 60 ng/L, 11.8 to 87.8 μg/kg dry wt. and 75 – 450 μg/kg dry in sea water, sediments and plankton respectively. Sampling sites were fixed according to the river discharge in each and every perfection sea lines. By this higher and lower value experiences that near to the mouth given significantly higher while comparing to offshore. The bioconcentration factor (BCF) of diuron from the concentration of diuron in sea water and in plankton, it was ranged80-15000 (average 4520), but were estimatednot to be widely different from Watanabe et al. (2004)*, who estimated on nonylphenol from Hiroshima bay. From the results of this study it can be concluded that residue levels found in the water, sediment and plankton may not likely produce acute toxicity effects to larger animals, but the accumulation of these same concentration may be detrimental to aquatic organisms.