Heavy metal and metalloid accumulation in wild brown trout (Salmo trutta L., 1758 complex, Osteichthyes: Salmonidae) from a mountain stream in Sardinia by ICP-OES

Angioni Alberto,Corrias Francesco,Alessandro Atzei,Lai Carla,Sabatini Andrea,Russo Mariateresa,Palmas Francesco

doi:10.1007/s10661-021-09204-w

Abstract

This paper reports heavy metal and metalloid accumulation in wild brown trout (Salmo trutta L., 1758 complex) raised in freshwater and uncontaminated Sardinia system (Italy). Metals are widespread pollutants of aquatic systems, and their contamination can originate from anthropogenic activities such as industrial waste, agricultural and domestic environments, and geochemical release. Fish has a relevant position within the human diet; moreover, fishes can accumulate metals, making them a valuable tool as biomarkers for risk assessment studies. The concentration of 22 metals and metalloids after chemical digestion was assessed by inductively coupled plasma-optic emission spectroscopy (ICP-OES) in both the guts and the edible part (EP, muscle + skin) of brown trout. The results, expressed as μg g−1, showed different levels of accumulation in the EP and guts, following the series Cu > Zn > Ba > Al > Sr > Fe > Pb and Fe > Al > Hg > As > Mn > Cu > Ba > B > Zn > Pb, respectively. PCA analysis showed a fairly good correlation between the total lipid and SAFA content and Cd, Hg, and Pb accumulation in the gut. Non-carcinogenic risk assessment, expressed as THQ (target hazard quotient), showed values far below 1 for all metals in muscles, while high As and Hg contamination of the gut draws attention to possible health risks which should be discarded from the fish before consumption. TR (target cancer risk) values showed alarmingly high values for As and Cd when the fish were consumed entirely (gut + EP), while Pb levels were far below the safety levels.

Highlights

Heavy metals are naturally occurring element present in trace amounts that can contaminate animals, vegetables, and fish along the food chain and are a problem for human safety (Masindi & Muedi, 2018)
Regarding Hg, we considered the reference doses (RfDs) of methyl mercury, assuming that all mercury found was in this organic form (MeHg)
Samples of brown trout ranged from 83.52 to 140.48 g in body weight (BW) and from 15.19 to 25.53 cm in total length (TL), while the gut weight ranged from approximately 10.56 ± 8.91 g (± RSD)

Summary

Introduction

Heavy metals are naturally occurring element present in trace amounts that can contaminate animals, vegetables, and fish along the food chain and are a problem for human safety (Masindi & Muedi, 2018). Maximum levels of heavy metals have been set in foodstuffs (EC 1881/2006, 2020; EC 629/2008, 2020), together with the official method of analysis (EURL, 2012). Fish and other water organisms can be affected by water pollution, mainly accumulating chemical substances that remain in the water columns for a relatively long time (Gündoğdu & Erdem, 2008). Metals can positively affect organisms; they can affect fish’s biochemical functions in terms of growth, reproduction, and wellbeing (Wang et al, 2017a, b). The concentration of heavy metals in fish has been extensively studied over the past several decades. Researchers have shown that the degree of metal accumulation in fish is dependent on the metal type, fish species, age, sex, geographical distribution, and tissue (Petrovic et al, 2013; Ptashynski et al, 2002)

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