Introduction
The significant increase in the amount of heavy metals in the
aquatic environment due to anthropogenic activities
(Puttiwongrak et al. 2019) makes heavy metals the topic of
considerable attention given their toxicity, chronic persistence, bioaccumulation, and biomagnification at different trophic levels (Cherfi et al. 2015; Chouvelon et al. 2019). Heavy
metals such as iron (Fe), zinc (Zn), copper (Cu), cobalt (Co),
manganese (Mn), nickel (Ni), chromium (Cr), or selenium
(Se) are essential for good physiological functioning of fish
and human (Justino et al. 2016). However, dietary deficiencies
of each of these trace metals are associated with specific medical disorders (Cousins and Liuzzi 2018), while some metals,
such as arsenic, cadmium, and lead, are non-essential even in
trace amounts (Rajeshkumar and Li 2018). Most marine organisms tend to accumulate heavy metals from their habitat
via the gills and skin or through food (Xie et al. 2013; Iamiceli
et al. 2015). Generally, heavy metal accumulates in all the
vital organs of the fish (Javed and Usmani 2019) and could
be the cause of apoptosis in marine fishes (Cuesta et al. 2016).
Consumption of seafood has a beneficial health effect
(Daschner 2016; Ballesteros et al. 2020). It helps to reduce
the incidence of diabetes and the development of cardiovascular disease (Ward and Hintze 2016). Moreover, fish is rich in
omega-3 fatty acids (Prato and Biandolino 2015) that are vital
for normal brain function and cognitive development (Babenko
2016). In added to being a source of proteins and minerals
useful for the wellness of humans (Bruno et al. 2019), fishes
have been used as a biomarker for trace metal pollution in the
aquatic environment (Łuczyńska et al. 2018). In the
Mediterranean eating habits, fish remains an essential ingredient (Hidalgo-Mora et al. 2020). As follows, to satisfy the increased demand for seafood products, aquaculture was developed in the Mediterranean Sea (Angel 2013). The main farmed
finfish species in the region are gilthead sea bream (Sparus
aurata) (Teulier et al. 2019). Its production in Algeria is estimated at approximately 750 tons in 2018, and it is carried out in
coastal ponds, or in the open sea cage (DGPA 2018).
The Mediterranean Sea has been significantly affected by
trace element pollution (Paraskevopoulou et al. 2014), and
fish consumption is the main source of these contaminants
to humans (Damiano et al. 2011). The monitoring of heavy
metals in aquatic resources is therefore required to guarantee
the safety of aquatic products and human health (Ezemonye
et al. 2019) since the ingestion of contaminate products might
threaten public health. One of the principal mechanisms responsible for metal toxicity has been attributed to oxidative
stress (Madkour 2020) involved in preterm births (Shachar
et al. 2013), and damage to biomolecules like lipids and
DNA, leading to cardiovascular disease (Melila et al. 2019)
and tumor development (Wallace and Buha Djordjevic 2020)
as well as disorders of the nervous and digestive systems
(Andersen et al. 2017; Su et al. 2017). Previous studies have
been carried out in this way in the Mediterranean region
(Marengo et al. 2018; Traina et al. 2019), including the
Algerian coastal (Ansel and Benamar 2018; Ouali et al.
2018; Mehouel et al. 2019). However, the specific objectives
of the present research were to determine the levels of toxic
heavy metals (As, Cd, and Pb) and essentials elements (Cu,
Zu) in the muscle of wild and farmed (Sparus aurata,
Linnaeus 1758) from Algerian coasts, as also to assess the
potential health risk for consumers by calculating the estimated daily intake (EDI) and the target hazard quotient (THQ) for
the cited elements. Nevertheless, the available data on the
concentration of heavy metals in gilthead sea bream from
Algerian coastal is scarce in the literature, and so this research
serves as a baseline for possible further investigation.
Furthermore, to the best of our knowledge, this is the first
study on heavy metal concentrations in farmed and wild
Sparus aurata, as well as on the estimation of the health risk
associated trough the consumption of this highly appreciated
fish by the Mediterranean population. All analyses were conducted by using validated and accredited methods.
Material and methods
Fish sampling
In spring and autumn 2018, wild gilthead sea bream was purchased at the Algiers fish market, which caters to fish from all
over the Algerian coast. Farmed ones were collected from two
sites, Tizi Ouzou (36° 54′ N, 4° 25′ E) in north-central Algeria
and Ain Temouchent (35°32′ 31″ N, 1° 07′ 19″ W) in northwestern Algeria (Fig. 1), characterized by different farming
method (in floating cages and raceway, respectively) and distinct levels of pollution. The economy of these sectors was
based on tourism, fishing, and agriculture. Species were directly transferred to the laboratory on ice. This study focused
on the determination of heavy metals As, Cd, Cu, Pb, and Zn
in fish muscle due to their excessive consumption.
Sample preparation and analysis
The total length (cm) and body weight (g) were measured for
each organism before preparation, and all biometric details are
presented in Table 1. In order to reduce contamination, the
edible parts were removed with a stainless steel scalpel. The
samples obtained were packed in pre-decontaminated polyethylene containers and frozen at −18 °C for further analysis.
Mostly, all analytical procedures were performed following
modified protocols described by Bachouche et al. (2017)
and Núñez et al. (2018). In digestion flask, a mixture of
HNO 3 -HClO 4 (8:3) (Merck, 99%) was added to 1.5 g of homogenized muscle tissues. The digestion flasks were held on
Environ Sci Pollut Res
The significant increase in the amount of heavy metals in the
aquatic environment due to anthropogenic activities
(Puttiwongrak et al. 2019) makes heavy metals the topic of
considerable attention given their toxicity, chronic persistence, bioaccumulation, and biomagnification at different trophic levels (Cherfi et al. 2015; Chouvelon et al. 2019). Heavy
metals such as iron (Fe), zinc (Zn), copper (Cu), cobalt (Co),
manganese (Mn), nickel (Ni), chromium (Cr), or selenium
(Se) are essential for good physiological functioning of fish
and human (Justino et al. 2016). However, dietary deficiencies
of each of these trace metals are associated with specific medical disorders (Cousins and Liuzzi 2018), while some metals,
such as arsenic, cadmium, and lead, are non-essential even in
trace amounts (Rajeshkumar and Li 2018). Most marine organisms tend to accumulate heavy metals from their habitat
via the gills and skin or through food (Xie et al. 2013; Iamiceli
et al. 2015). Generally, heavy metal accumulates in all the
vital organs of the fish (Javed and Usmani 2019) and could
be the cause of apoptosis in marine fishes (Cuesta et al. 2016).
Consumption of seafood has a beneficial health effect
(Daschner 2016; Ballesteros et al. 2020). It helps to reduce
the incidence of diabetes and the development of cardiovascular disease (Ward and Hintze 2016). Moreover, fish is rich in
omega-3 fatty acids (Prato and Biandolino 2015) that are vital
for normal brain function and cognitive development (Babenko
2016). In added to being a source of proteins and minerals
useful for the wellness of humans (Bruno et al. 2019), fishes
have been used as a biomarker for trace metal pollution in the
aquatic environment (Łuczyńska et al. 2018). In the
Mediterranean eating habits, fish remains an essential ingredient (Hidalgo-Mora et al. 2020). As follows, to satisfy the increased demand for seafood products, aquaculture was developed in the Mediterranean Sea (Angel 2013). The main farmed
finfish species in the region are gilthead sea bream (Sparus
aurata) (Teulier et al. 2019). Its production in Algeria is estimated at approximately 750 tons in 2018, and it is carried out in
coastal ponds, or in the open sea cage (DGPA 2018).
The Mediterranean Sea has been significantly affected by
trace element pollution (Paraskevopoulou et al. 2014), and
fish consumption is the main source of these contaminants
to humans (Damiano et al. 2011). The monitoring of heavy
metals in aquatic resources is therefore required to guarantee
the safety of aquatic products and human health (Ezemonye
et al. 2019) since the ingestion of contaminate products might
threaten public health. One of the principal mechanisms responsible for metal toxicity has been attributed to oxidative
stress (Madkour 2020) involved in preterm births (Shachar
et al. 2013), and damage to biomolecules like lipids and
DNA, leading to cardiovascular disease (Melila et al. 2019)
and tumor development (Wallace and Buha Djordjevic 2020)
as well as disorders of the nervous and digestive systems
(Andersen et al. 2017; Su et al. 2017). Previous studies have
been carried out in this way in the Mediterranean region
(Marengo et al. 2018; Traina et al. 2019), including the
Algerian coastal (Ansel and Benamar 2018; Ouali et al.
2018; Mehouel et al. 2019). However, the specific objectives
of the present research were to determine the levels of toxic
heavy metals (As, Cd, and Pb) and essentials elements (Cu,
Zu) in the muscle of wild and farmed (Sparus aurata,
Linnaeus 1758) from Algerian coasts, as also to assess the
potential health risk for consumers by calculating the estimated daily intake (EDI) and the target hazard quotient (THQ) for
the cited elements. Nevertheless, the available data on the
concentration of heavy metals in gilthead sea bream from
Algerian coastal is scarce in the literature, and so this research
serves as a baseline for possible further investigation.
Furthermore, to the best of our knowledge, this is the first
study on heavy metal concentrations in farmed and wild
Sparus aurata, as well as on the estimation of the health risk
associated trough the consumption of this highly appreciated
fish by the Mediterranean population. All analyses were conducted by using validated and accredited methods.
Material and methods
Fish sampling
In spring and autumn 2018, wild gilthead sea bream was purchased at the Algiers fish market, which caters to fish from all
over the Algerian coast. Farmed ones were collected from two
sites, Tizi Ouzou (36° 54′ N, 4° 25′ E) in north-central Algeria
and Ain Temouchent (35°32′ 31″ N, 1° 07′ 19″ W) in northwestern Algeria (Fig. 1), characterized by different farming
method (in floating cages and raceway, respectively) and distinct levels of pollution. The economy of these sectors was
based on tourism, fishing, and agriculture. Species were directly transferred to the laboratory on ice. This study focused
on the determination of heavy metals As, Cd, Cu, Pb, and Zn
in fish muscle due to their excessive consumption.
Sample preparation and analysis
The total length (cm) and body weight (g) were measured for
each organism before preparation, and all biometric details are
presented in Table 1. In order to reduce contamination, the
edible parts were removed with a stainless steel scalpel. The
samples obtained were packed in pre-decontaminated polyethylene containers and frozen at −18 °C for further analysis.
Mostly, all analytical procedures were performed following
modified protocols described by Bachouche et al. (2017)
and Núñez et al. (2018). In digestion flask, a mixture of
HNO 3 -HClO 4 (8:3) (Merck, 99%) was added to 1.5 g of homogenized muscle tissues. The digestion flasks were held on
Environ Sci Pollut Res