Preliminary assessment of polybrominated diphenyl ethers (PBDEs) in the Scottish aquatic environment, including the Firth of Clyde

Abstract

This paper presents preliminary data on polybrominated diphenyl ethers (PBDEs) in the Scottish aquatic environment. Sediment and biota (fish liver, fish muscle and mussels) from a number of locations around Scotland were analysed for PBDEs with samples being from both remote and from potentially contaminated areas such as the former sewage sludge dump site at Garroch Head in the Clyde. PBDEs were measured in both cultivated, rope grown mussels and wild mussels collected from 5 sites around Scotland in 2006. Total PBDE concentrations (sum of tri- to hepta-BDEs) ranged from <limit of detection (LoD) to 2.36 μg kg⁻¹ wet weight, with the highest concentrations being found in mussels close to Aberdeen harbour. Most PBDE congeners were below detection limits but where they were detected, BDE47 and BDE99 were the main congeners. PBDEs were detected at low concentrations in flatfish muscle from 11 localities around Scotland, with total PBDE concentrations ranging from <LoD to 1.67 μg kg⁻¹ wet weight, with BDE47 being the dominant congener. Total PBDEs concentrations ranged from <LoD to 1.22 μg kg⁻¹ wet weight in brown trout muscle from 4 mountain lochs with the highest in fish from Lochnagar, a high level loch in the eastern Cairngorms. In contrast to the marine fish, BDE99 was the main congener in the brown trout. PBDEs were also measured in fish liver collected from the former sewage sludge dump site at Garroch Head in the Clyde, with total PBDE concentrations ranging from 4.1–536.1 μg kg⁻¹ wet weight. Concentrations were highest prior to the cessation of sewage sludge dumping in 1998. Total PBDE concentrations (sum of tri- to hepta-BDEs) in sediment cores collected in 2003 from Garroch Head and at a site 2.3 km south of Garroch Head ranged from <LoD to 23.4 μg kg⁻¹ dry weight. BDE209 was found at very high concentrations in the cores (2.3 to 98 125 μg kg⁻¹ dry weight). Highest PBDE concentrations were found in the top 4 cm of all cores, reflecting their more recent use.