Diuron concentrations along shorelines of Ishigaki and Iriomote islands, Japan

Abstract

Diuron (DCMU; 3-(3,4-dichlorophenyl)-1,1-dimethylurea) concentrations were analyzed at 24 sites along shorelines of Ishigaki and Iriomote Islands in September 2019. The diuron concentrations ranged from <0.6 to 32 ng l-1. Slightly high concentrations of diuron as 32 and 19 ng l-1 were observed at a fishing port in Iriomote and a mooring point for boats in Ishigaki, respectively, implying contamination likely from antifouling paints of boats. A slightly high concentration (14 ng l-1) of diuron was also found in the estuary of Arakawa River in Ishigaki Island, which implies land sources. In Iriomote Island, diuron concentrations were low (≤1 ng l-1) at all sites except for the port site. These results indicate generally low levels (below toxic levels for organisms) of diuron contamination at least at the timing of the present study.