HERBICIDE CONTAMINATION OF MEDITERRANEAN ESTUARINE WATERS - RESULTS FROM A MED POL PILOT SURVEY

The reported data offers the first extensive evidence that significant concentrations of some herbicides persist in marine systems. In the a reas studied (the Ebro delta on the Eastern Coast of Spain, the Rhone delta in the South of France, the River Po, Italy/the Northern Adriati c Sea, the Thermaikos and Amvrakikos Gulfs in Greece and the Nile delt a in Egypt) the most commonly encountered herbicides were atrazine, si mazine, alachlor, metolachlor and;molinate. In general, aqueous concen trations encountered in the riverine inputs were comparable to (or bel ow) those reported for rivers in other regions of the World. Concentra tions generally declined from freshwater locations through estuaries t o marine waters. The distributions of some herbicides (e.g. the triazi nes) in sediments endorsed the environmental persistence of these comp ounds. In contrast to the other areas studied, no herbicides were dete cted in samples from a preliminary survey of the Nile delta.