Dietary uptake of dioxins (PCDD/PCDFs) and dioxin-like PCBs in Spanish aquacultured turbot (Psetta maxima)

Abstract

The human population is exposed to dioxins (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs) mainly through diet; bioaccumulation and biomagnification in aquatic environment results in fishery products and by-products being an important vector to humans. The determination of PCDD/Fs and dl-PCBs in fillets of young turbots (Psetta maxima) (0–2 years) from aquaculture plant (Galicia, Spain) (N = 21) and in feeding stuffs were carried out, and dietary accumulation values and lipid-normalized biomagnification factors (BMF) relating concentration in fish and in feed were calculated. Levels found in feeding stuffs (0.5 pg TEQ-PCDD/F/g and 1.6 pg TEQ-dl-PCB/g), and turbots (0.13–0.27 pg TEQ-PCDD/F/g fresh weight and 0.35–1.2 pg TEQ-dl-PCB/g fresh weight) were below maximum permitted levels set by EC. Levels of toxic compounds in feeding stuff are reflected in fish fillets; predominant isomers are 2,3,7,8-TCDF, OCDD, 1,2,3,7,8-PeCDF, 2,3,4,7,8-PeCDF and 1,2,3,4,6,7,8-HpCDD, and PCBs 118, 105, 156 and 167. Relevant compounds accounting for total toxicity are the same congeners in feeding stuff and turbots: 2,3,4,7,8- PeCDF; 2,3,7,8-TCDF; 2,3,7,8-TCDD and 1,2,3,7,8-PeCDD, and PCB 126. Higher accumulation efficiency values were obtained for dl-PCBs (30–46%); tetra- and penta-chloro substituted PCDD/Fs showed the highest values (27–34%) of the PCDD/F group. Biomagnification was shown for these compounds (BMF around 1.5).

* Presented as a poster at the 2nd International Symposium on ‘Recent Advances in Food Analysis’ held in Prague, Czch Republic, November 2--4th 2005.

Keywords:

• Dietary accumulation
• farmed fish
• turbot
• feeding stuffs
• dioxins
• dioxin-like PCBs

Acknowledgements

This work was funded with Grant CAL 01-031 from National Institute for Agriculture and Nutrition Research and Technology, Spanish Ministry of Science and Technology (INIA-MCYT). Authors are grateful to the contributions of Ana I. Bernardino and Gerardo Fernández.

Notes

* Presented as a poster at the 2nd International Symposium on ‘Recent Advances in Food Analysis’ held in Prague, Czch Republic, November 2--4th 2005.