Occurrence of retene and resin acids in sediments and fish bile from a lake receiving pulp and paper mill effluents

Retene (7-isopropyl-1-methylphenanthrene) is a dialkyl-substituted PAH deri ved thermally and microbially from dehydroabietic acid. We have analyzed fo r retene and several resin acids in sediments at five depths at several sit es in a lake receiving effluents from three pulp and paper mills, and two u pstream reference sites. The highest concentration of retene was 1,600 mu g /g dry weight (11,700 mu g/g organic carbon [OC]) and of total resin acids was 1,500 mu g/g dry weight (9,300 mu g/g OC). Twelve kilometers downstream from the point of bleached-kraft mill effluent (BKME) discharge, the conce ntration of retene at a depth of 5 to 10 cm was 16 mu g/g dry weight (650 m u g/g OC) and of resin acids was 139 mu g/g dry weight (1,700 mu g/g OC). U pstream of the BKME discharge, the concentration of retene was below 0.1 mu g/g dry weight and of resin acids was below 70 mu g/g dry weight. To asses s the bioavailability of retene to fish we determined its concentration in the bile of roach (Rutilus rutilus) and perch (Perca fluviatilis) caught 1 to 2 km downstream of pulp and paper mills and in the reference area. Reten e was bioavailable to roach, which primarily feed on benthic organisms; how ever, retene was not detected in perch bile.