UPTAKE OF PCBS IN FISH IN A CONTAMINATED RIVER SYSTEM - BIOCONCENTRATION FACTORS MEASURED IN THE FIELD

We have studied PCB concentration and domain (one to three congeners) distribution in water and fish along a gradient of a contaminated rive r system. The river was contaminated by a small lake that contains abo ut 400 kg of PCB in the sediment. The PCB concentration in water in th e outlet from the lake was 8.6 ng/L, which was 12 times higher than up stream. PCB concentration in fish from the lake was about 20 times hig her than the concentration in fish from upstream lakes. The polluted l ake considerably influenced domain distribution in both water and fish . The fish bioconcentration factors (BCFs) for low to highly chlorinat ed domains showed a bell-shaped curve. BCFs for low chlorinated PCBs w ere less than for more highly chlorinated ones, but for the largest mo lecules the BCFs were reduced. The bell-shaped curve remained also whe n domain numbers were transformed into corresponding log K-OW values. BCFs for the same domains were shown to vary between stations.