Trace metal concentrations in water and edible tissues of Liza ramada from the Northeastern Moroccan Mediterranean coast: Implications for health risk assessment

Abstract

This study aims to assess the level of metal contamination (Hg, Pb, and Cd) in water and edible tissues of Liza ramada from the Northeastern Moroccan Mediterranean coast, in order to assess the risk associated with the consumption of this species. 25 specimens of adult L. ramada and water samples were collected at two stations (port of Béni Ansar and Ras Kebdana) during the winter and the summer seasons of 2019. Metal concentrations were determined using graphite furnace and cold vapor atomic absorption spectrometry. Metal concentrations in water showed generally low values, with an order of increasing concentrations of Hg < Cd < Pb. Similarly, metal concentrations in L. ramada muscles showed low values below the guidelines set down by the European Commission Regulation, with an order of increasing concentrations of Cd < Hg < Pb. The calculation of the metal pollution index showed that the fish at the port of Béni Ansar are more contaminated than those at the port of Ras Kebdana. In addition, metal values in the summer are relatively high compared to the winter. Statistical analysis by the student’s t-test for equality of means showed that the effect of the season is more significant on the metals bioaccumulation; moreover, positive correlations were found between Hg–Pb and Pb–Cd in fish muscle. Furthermore, there is a significant positive correlation between metal concentrations and length and weight of L. ramada, except for Cd. L. ramada presented relatively high bioaccumulation factor values, particularly for Hg. The estimation of non-carcinogenic health risks by target hazard quotients (THQ) and maximum safe consumption suggest that these species do not pose a health risk to consumers (THQ < 1), and may be consumed at will, without exceeding 16 kg per week for children.