An assessment of persistent organic pollutants in Scottish coastal and offshore marine environments

Abstract

Concentrations of persistent organic pollutants (POPs), including polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) were determined in sediment and biota (fish liver) from around Scotland. The concentrations were investigated using assessment criteria developed by OSPAR and ICES. Organic contaminant concentrations, PAHs, PCBs and PBDEs in sediment, and PCBs and PBDEs in fish liver, were significantly higher in the Clyde compared to all other sea areas. This is mainly due to historic industrial inputs. Highest PCB and PAH concentrations were found in the strata furthest up the Clyde estuary, with concentrations of POPs in these strata being at levels such that there is an unacceptable risk of chronic effects occurring in marine species. Furthermore, for PAHs in Clyde sediment there was a significant negative gradient going from north to south towards the open sea. PAH and PCB concentrations in sediment and biota in all other Scottish sea areas (except for PCBs in sediment from East Scotland) were unlikely to give rise to pollution effects, being below relevant assessment criteria. Although no assessment criteria are available for PBDEs, the concentrations observed in Scottish sediments were low with all congeners below the limit of detection (LoD; 0.03 µg kg(-1) dry weight) in 140 out of a total of 307 samples analysed. Where PBDEs were detected, the dominant congeners were BDE47 and BDE99. PBDEs were detected in fish livers, although concentrations were less than 150 µg kg(-1) lipid weight in all sea areas except the Clyde where concentrations ranged between 8.9 and 2202 µg kg(-1) lipid weight. Few trends were detected in contaminant concentrations in biota or sediment at any Scottish site with more than five years data. Downward trends were detected in PAHs in sediment from the Clyde, Irish Sea and Minches and Malin Sea and PCBs in fish liver from the Moray Firth. Rules were developed for the aggregation of the contaminant data across a sea area. An overall assessment for each sea area was then assigned, looking at the frequency of sites or strata within each sea area that were above or below the relevant assessment criteria. Overall the status of the various sea areas, with respect to the assessed POPs, can be considered to be acceptable in that they were below concentrations likely to result in chronic effects for all sea areas except the Clyde.

‘Towards a unified approach for the determination of the bioaccessibility of organic pollutants’

“…omega 3 polyunsaturated fatty acids) which have beneficial health effects such as the reduction of coronary heart disease and strokes. However, this high lipid content also results in oily fish being a sink for HOCs (Ondarza et al, 2014;Webster et al, 2011). In a Spanish total diet study fish and seafood were the highest contributors to the dietary intake of PCDD/Fs, PCBs, PBDEs and PCDEs, and were the third most important food group for PAHs and HCB (Martí-Cid et al, 2007).…”

Halogenated persistent organic pollutants in relation to trophic level in deep sea fish

“…PBDE concentrations were significantly lower in the black scabbard liver compared to concentrations in the liver of the roundnose grenadier and black dogfish. Similar to the PCBs, PBDE concentrations were lower than found in shallow water species from more industrialised areas in Scotland such as the Clyde, where mean RPBDE9 concentrations in plaice liver ranged from 50.1 lg kg À1 lipid weight to 430 lg kg À1 lipid weight (Webster et al, 2011b). Currently there is only very limited published data on PBDEs in deep water fish.…”

“…Concentrations in shallow water species from industrialised areas are normally >500 lg kg À1 lipid weight (Webster et al, 2005(Webster et al, , 2011b, as such the value of 500 lg kg À1 lipid weight in liver has been taken as a transition point between typical background values and those greater than background. Concentration for P ICES7 PCBs were mostly <500 lg kg À1 lipid weight, with just twenty-three of the ninety-five fish liver (mainly roundnose grenadier) exceeding this concentration.…”

“…6b). Shallow water fish from Scottish waters were also found to exceed the EAC passive for CB118, even in areas remote from industrial and urban activity and with RICES7 PCB concentrations <500 lg kg À1 lipid weight (Webster et al, 2005(Webster et al, , 2011b. To aggregate results for PCB congeners within a traffic light assessment system, the rule that was adopted was that if 2 congeners were classed as 'red' then the overall PCB classification would be 'red' (Webster et al, 2011b).…”

“…6a). PCB concentrations in shallow water fish liver, even from offshore sites away from point sources, are rarely below BACs (Webster et al, 2005(Webster et al, , 2011b.…”