抄録
Water quality problems have been studied in the Naka River run through Saitama to Tokyo from April 1994 to September 2004 at Saitama, Japan. Mobility inhibition test using D. magna of the Naka River water made clear that acute toxic chemicals remained in the river waters in the mid-1990s. The pollution by the chemicals acute toxic to D. magna remained until 2000, but after 2001 the pollution decreased remarkably. Several river waters polluted by organophosphate insecticides were examined by D. magna test battery with and without piperonyl butoxide (PBO) and the D. magna test battery of the Naka River waters were also performed. These results indicate that the mobility inhibition test battery with and without PBO is an effective tool to identify whether organophosphate insecticides are responsible for the toxicity of complex polluted river waters or not and the mobility inhibition of D. magna in the Naka River waters was shown to be caused by organophosphate insecticides. We also discuss what the serious organophosphate insecticide pollution of the river waters was improved by after 2001.
