Halogenated persistent organic pollutants in Scottish deep water fish

Abstract

Halogenated persistent organic pollutants (chlorobiphenyls (CBs), polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD) and tetrabromobisphenol-A (TBBP-A)) and total lipid content were measured in the liver and muscle of three species of deep water fish (black scabbard, roundnose grenadier and black dogfish) collected from the Rockall Trough, to the west of Scotland, in 2006. CB concentrations (ΣICES (International Council for the Exploration of the Seas)7 CBs) >500 µg kg⁻¹ lipid weight) were found in 9 of the 31 deep water fish liver samples. Non-ortho CBs were measured in samples with the highest ortho CB concentrations. Non-ortho CBs (CB81, 77, 126 and 169) were not detected in any of the fish muscle samples. In liver, CB81 was not detected in any of the samples while CB169 was detected in all but one sample. The total ‘dioxin-like’ CB concentration was calculated based on the 5 mono-ortho and 4 non-ortho CBs measured. The non-ortho CB concentration made a very small contribution to the total ‘dioxin-like’ CB concentrations (<1%). Concentrations for the individual ICES7 CBs in fish liver were above OSPAR Background Assessment Concentrations (BACs) in all three species, except for CB28 and 101 in black dogfish. Toxic Equivalent (TEQs) concentrations calculated for the five mono-ortho and four non-ortho CBs measured, and estimated TEQs calculated using published models in the fish muscle indicated that consumption of deep water fish muscle is unlikely to represent a risk to human health. However, dioxins and furans were not measured and the contribution to the calculated TEQs from these compounds was not taken into account. Calculated and estimated TEQs for some roundnose grenadier liver samples exceeded the 25 pg g⁻¹ wet weight limit for fish liver and, therefore, there may be a health risk if consumed. PBDEs were detected in both the liver and muscle of the deep water fish, whilst HBCD and TBBP-A were not detected in any of the deep water fish.