Diuron, Irgarol 1051 and Fenitrothion contamination for a river passing through an agricultural and urban area in Higashi Hiroshima City, Japan

A study was conducted on the pesticides Diuron, Irgarol 1051 and Fenitrothion in Kurose River water, Higashi Hiroshima, Japan for a period of one year to assess the contribution of agriculture and urban activities on pesticide pollution of the river. Samples were analysed by a reverse phase HPLC system. The maximum pesticide concentrations were; 4620 ng/L, 50 ng/L and 370 ng/L for Diuron, Irgarol 1051 and Fenitrothion, respectively. While Diuron and Fenitrothion were detected at all sites, Irgarol 1051 was only present at Izumi, a high density urban and industrial area which also registered the highest concentrations of the pesticides. The pattern showed by Diuron and Fenitrothion was linked to farming activities. Also, Diuron and Fenitrothion concentration correlated with pesticide utilization data for Hiroshima Prefecture. Irgarol 1051 showed a different pattern to that of Diuron and Fenitrothion and its source was attributed to paint. It was noted that 78% and 42% of water samples at Izumi sampling site exceeded the European Union (EU) guidelines for Diuron and Fenitrothion, respectively.