Monitoring of pesticide and heavy metal discharge of the major rivers and drainage canals into the Mediterranean Sea in the north-east coastal zone, Turkey

Pesticide and toxic metal contamination in 118 water samples of the two major rivers (Seyhan and Ceyhan) and their four major drainage canals in Cukurova basin, Turkey were analyzed for 11 organochlorine and 15 organophosphate pesticides that have been used in the basin. The samples were taken within 15 days every month during a 15 months lasting period near the points of discharge to the sea. Organochlorine pesticides were only detected in water samples of the summer period. In twenty soil samples taken during summer from the agricultural lands nearby, the same pesticides have been found, but with increasing concentrations. Ten metals have been monitored in the water samples. Iron and zinc were found in all water samples. Lead, aluminum and nickel were the second most frequently and the rest of the metals the least observed. The Ceyhan river had a higher mean value and higher variance for iron when compared with the Seyhan river. Both rivers showed similar zinc contents with comparably high variance indicating irregular discharges of zinc-containing materials. In general, the drainage canals have higher iron contents and variances when compared with the rivers.