Assessment of Toxic Substances in freshwater Fish from the Tajo River Basin (Spain)

Abstract

Having taken into account the information obtained from the previous results obtained in the study of dangerous substances in water and fish from eight stretches of the Tajo river basin [1], the bioaccumulation of the most relevant pollutants is observed, in the liver and muscle of fish. In that study, eight streams were studied in different locations of the Tajo river basin, suspected to be, to a higher or lower degree, affected by chemical pollution, as well as one reference stream of clean, non-impacted water, the Lozoya stream. Water and fish from these streams are analysed for hazardous substances. The present levels of these pollutants, considered acceptable for non-polluted streams, are defined. The substances which tend to accumulate in fish are tissues copper, zinc, DDT, dieldrin, and endrin. HCH, HCB, lindane, and PCBs, mostly in hepatic tissue.