Fate and distribution of the mothproofing agents dieldrin and eulan WA New in Loch Leven, Kinross, 1964–1979

Following the cessation of the use of dieldrin in 1963 and the subsequent use of Eulan WA New at the textile mill in Kinross, Scotland, the fate and distribution of the mothproofing agents in the Loch Leven environment were studied. Fish samples analysed between 1963 and 1970 showed a decline in dieldrin concentrations with a half-life of 0·56–0·82 years (r > 0·87). Samples of water, sediment, zooplankton and fish were taken for analysis during 1978–1979. About 50% of the Eulan WA New remained in the soluble ionic form and was discharged into the River Leven. Much of the remaining 50% was associated with particulate matter and sediment. Less than 10% was associated with the biota. The samples were analysed using GC-ECD and GC-MS-DS with decachlorobiphenyl as the internal standard.