Bioaccumulation of DDT and its metabolites in the Miedzyodrze ecosystem, Poland

The aim of this study was to estimate the degree of DDT and its metabolite bioaccumulation (biotasediment accumulation factor, BSAF and biota-water accumulation factor, BCF) in certain aquatic biota collected from the lower Oder River. The study comprised surface water and sediments, as well as soft tissue of compressed river mussel (Anodonta complanata) and certain organs of roach (Rutilus rutilus) and spinycheek crayfish (Orconectes limosus). Regarding a 30-year-old ban on DDT use in Poland, relatively low concentrations of the compound were expected. DDT and its metabolites were detected in all the examined samples. ΣDDT levels in water and sediments averaged 0.157 ± 0.068 µg/dm³ and 11.478 ± 2.292 µg/kg d.w., respectively. Roach organs contained higher levels of these compounds than crayfish and bivalves. DDT was accumulated mainly in the liver and gonads (45.823 ± 9.845 and 19.815 ± 4.854 µg ΣDDT/kg w.w., respectively). In roach organs p,p’ DDE predominated. BSAF values for p,p’ DDE and p,p’ DDD in the liver and p,p’ DDE in the gonads exceeded the predicted theoretical value (2.4). In water and sediment samples from several sites, the DDT/DDE ratio was higher than 1, which indicated fresh input of DDT in the studied area or inhibition of its breakdown.