Risk assessment of methyl-mercury intake through cephalopods consumption in Portugal

Abstract

The intake of methyl-mercury (methyl-Hg) through the consumption of three common cephalopod species, cuttlefish (Sepia officinalis), squid (Loligo vulgaris) and octopus (Octopus vulgaris), in Portugal as well as the associated probability of exceeding the provisional tolerable weekly intake (PTWI) were estimated by combining methyl-Hg contamination levels in these three cephalopods with constructed consumption scenarios and with a hypothesised consumption distribution for the general Portuguese population. It was found that squid presents no serious health concern with respect to methyl-Hg, but cuttlefish and octopus consumption should not exceed two 150 g meals per week. Moreover, the methyl-Hg risk assessment for Portuguese consumers showed no risk concerning the observed cephalopods consumption levels. However, besides methyl-Hg, other toxic metals present in cephalopods, such as cadmium, may be a serious health concern and the methyl-Hg risk can be compounded by the risk of other foods containing significant methyl-Hg levels, especially long-lived sea predators. Accordingly, a cautionary note must be attached to advised maximum consumptions, which may be revised by future studies. Tail estimation (TE) estimator was more accurate for lower probabilities, rendering accurate risk estimations different from zero. However, for higher probabilities, the much simpler plug-in (PI) estimator could be applied. Additionally, limitations of a deterministic approach were identified.

Keywords:

• fish and fish products
• metals – nutritional
• risk assessment – modelling
• risk assessment
• exposure assessment
• metals analysis

Acknowledgements

This research was funded by Project Qalibra (Quality of Life – Integrated Benefit and Risk Analysis – 022597). Carlos Cardoso would like to thank FCT PhD grant (SFRH/BD/36455/2007). Furthermore, the authors would like to thank Jessica Tressou, PhD (INA-PG, Paris, France) for excellent technical support to the study.