Mercury in fish: Concentration vs. fish size and estimates of mercury intake

Abstract

Total mercury concentrations were determined in different fish size classes of commercial importance such as, conger eel (Conger conger), starry ray (Raja asterias), forkbeard (Phycis blennoides), frostfish (Lepidopus caudatus), striped mullet (Mullus barbatus), red gurnard (Aspitrigla cuculus) and yellow gurnard (Trigla lucerna) in order to evaluate variations in consumer exposure to mercury as a function of fish consumption of a spectrum of different sizes. The highest mean levels of total mercury were detected in conger eel (0.80 µg g⁻¹) and starry ray (0.75 µg g⁻¹). Forkbeard (0.67 µg g⁻¹), frostfish (0.59 µg g⁻¹) and striped mullet (0.55 µg g⁻¹) showed slightly lower levels, while red gurnard (0.33 µg g⁻¹) and yellow gurnard (0.22 µg g⁻¹) exhibited the lowest concentrations. The results of linear regression analysis showed a significant relationship between mercury concentrations and fish size for all species. Consequently, dietary consumption of larger size specimens leads to an increase in the exposure level for consumers. Understanding by consumers of all factors leading to an increase of exposure to mercury is the first step to enable them to make decisions about eating fish.

Keywords:

• Total mercury
• fish
• risk assessment
• provisional tolerable weekly intake (PTWI)