Edited by: Lotfi Rabaoui, King Fahd University of Petroleum and Minerals, Saudi Arabia
Reviewed by: Periyadan K. Krishnakumar, King Fahd University of Petroleum and Minerals, Saudi Arabia; Radhouan El Zrelli, Independent Researcher, Aspach-Le-Bas, France
This article was submitted to Marine Pollution, a section of the journal Frontiers in Marine Science
This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
A risk assessment, related to the consumption of farmed sea bass, was carried out by meta-analysis, taking into account the concentration of trace metals (Cd, Pb, Hg) reported in the literature, the estimated weekly intake (EWI), the provisional tolerable weekly intake (PTWI), and the target hazard quotient (THQ). The concentrations of Cd, Pb, and Hg in farmed sea bass marketed in Sicily (Southern Italy) were also assessed by inductively coupled plasma mass spectrometry (ICP-MS) and atomic absorption spectroscopy (AAS) to have screening data for the comparison with literature results. In any case, the results obtained by meta-analysis and by screening were lower than the pre-established legal limits for each metal. The meta-analysis results showed very low levels of Cd (0.031 μg g–1 w.w.), Pb (0.110 μg g–1 w.w.), and Hg (0.023 μg g–1 w.w.). The EWI estimation confirmed safety limits for human health (0.004, 0.015, and 0.003 μg kg–1 for Cd, Pb, and Hg, respectively). Even the THQ demonstrated that farmed sea bass represent a secure food for humans (0.0006, 0.0005, and 0.0048 for Cd, Pb, and Hg, respectively). The comparison with our screening data showed a significant difference only for the Pb levels (
In recent decades, the demand for fish by consumers has increased significantly with the awareness of the positive effects on human health arising from the consumption of aquatic products (
To overcome this increasing demand, intensive aquaculture systems of different fish species were carried out. The contribution of aquaculture to world food supply of aquatic products has been increasing, in comparison to the decline in fish resources (
In the recent past, the Mediterranean aquaculture sector has steadily increased, becoming economically significant for the region (
In 2017, the total consumption of fresh seafood products mainly marketed in Italy was 336,799 tons; 18,243 tons concerns European sea bass (
Fish products represent a major source of polyunsaturated fatty acids (omega 3, omega 6), as well as other essential nutritional factors (proteins, minerals, vitamins) to human health, reducing cholesterol levels and the incidence of heart disease, stroke, and preterm delivery (
However, there is still apprehension of the consumption of these products because of the high ability of several marine organisms to accumulate contaminants [trace metals, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), dioxins, etc.], making them one of the most responsible of contaminants intake (
Farmed fish have the advantage of being reared and harvested under controlled conditions, so that hazards associated with fish consumption can be more easily controlled (
Human dietary exposure to trace metals derives, in general, from population dietary habits. For this reason, it is very important to deepen the consequences of contaminants presence in different food types (
The European Food Safety Authority (EFSA) provided updated information on the levels of trace metals found in a range of foods on the European market and estimated exposure using individual data from the Comprehensive European Food Consumption Database (
The present work aimed at assessing the risk of trace metals exposure related to the consumption of farmed sea bass consumed in Italy, by meta-analytic techniques and screening data from farmed sea bass samples marketed in Sicily.
A total of 16 farmed sea bass samples marketed in Sicily (Southern Italy) were collected during March–April 2015 as part of the SecurAqua Project to obtain a screening dataset for the risk assessment. Sea bass were bought not alive by randomly selecting some supermarkets in Sicily. All the samples were analyzed at the residues laboratory of the Istituto Zooprofilattico Sperimentale della Sicilia (IZSSi). Furthermore, these data were compared with the data obtained by meta-analysis based on what was stated on the label. All the 16 farmed sea bass samples came from farms located in Greece [
All solutions were prepared with analytical ultrapure grade reagents. Water for chromatography LiChrosolv® was purchased from Merck KgaA (Darmstadt, Germany). Ultrapure nitric acid 60% was purchased from Merck KgaA (Darmstadt, Germany). The standard solution was as follows: the multielement calibration solutions were prepared at different concentration levels (0.001–50 μg/L) from 1,000 mg/L single element inductively coupled plasma mass spectrometry (ICP-MS) grade standard from VWR International LTD (Randon, Pennsylvania, United States). For Hg determination, the standards for the instrument calibration were prepared on the basis of monoelement-certified reference solution (VWR, Milan, Italy). A tuning solution for ICP-MS, capable of covering a wide range of masses (Ce, Co, Li, Mg, Tl, and Y, 1 μg/L) was purchased from Agilent Technologies (Santa Monica, CA, United States) to optimize the performance of ICP-MS before use. For the internal standard solution, 100 mg/L standard stock solution of scandium (Sc), yttrium (Y), indium (In), terbium (Tb), rhodium (Rh), lutetium (Lu), Lithium 6 (Li), indium (In), germanium (Ge), and bismuth (Bi) was purchased from Agilent Technologies (Santa Monica, CA, United States). Ultrapure grade carrier gas (Ar, 99.9995% pure) was purchased from SOL S.p.a. (Monza, Mi, Italy). Ultrapure grade dilution gas (He, 99.9995% pure) was purchased from SOL S.p.a. (Monza, Mi, Italy). Ultrapure grade dilution gas (H2 99.9995% pure) was purchased from SOL S.p.a. (Monza, Mi, Italy).
Cd and Pb determination was carried out according to
A first step at 600 W with a ramp for 10 min and a hold stage of 40 min.
A second step at 0 W with and hold time of 15 min.
The extracts were made up to 50 ml of volume with ultrapure water, filtered, and analyzed by 7700× series ICP-MS (Agilent Technologies, Santa Monica CA, United States). The samples extracted were pumped by a peristaltic pump from tubes arranged on an autosampler ASX-500 Series (Agilent Technologies, Santa Monica (CA), United States), combined with a quartz cyclonic spray chamber.
A calibration curve of eight standard points (BlankCal: 0.01–0.05–0.1–0.5–1–5–10–50 μg/L) was made to evaluate the linearity. A pool of digested samples was used for this test. The linearity of the calibration curve was considered acceptable for
All the results under the LOQ of the method were considered for the statistical analysis as half of the LOQ values, according to
The Hg levels were detected according to the protocols of
The amount of Hg present in the samples was detected and quantified according to calibration curves of five concentration points (0.050–2 mg kg–1). Hg was quantitatively measured by atomic absorption at 253.65 nm. The method was validated for repeatability and expanded measurement uncertainty according to ISO 17025:2018. LOD and LOQ of the method were also assessed. The validation procedure showed satisfactory results with repeatability values between 0.021 and 0.826 mg/kg for the five concentration points considered. The expanded measurement uncertainty showed a range of values between 0.020 and 0.710. The LOD and LOQ found were 0.041 and 0.050 mg/kg, respectively.
Meta-analysis refers to the statistical analysis of the data from independent primary studies focused on the same question, which aims to generate a quantitative estimate of the studied phenomenon (
The aims of a meta-analysis are the following:
increase power of the study by combining information from multiple studies;
estimate an average effect (a single synthetic effect measure instead of N distinct effect measures);
identify subsets of studies showing similar results; and
estimate which features of the studies may have led to differences in the results.
We calculated the concentrations of trace metals in the muscle of farmed sea bass by meta-analytic techniques according to
Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)—flow diagram for study selection.
We examined 311 articles with the inclusion criteria described below:
studies on the concentration of trace metals in sea bass (commercial size > 200 g) farmed in the Mediterranean countries published from 2002 to 2020; and
studies with quantitative estimates of the concentrations of trace metals in the muscle of farmed sea bass (mean, variability, and sample size).
We excluded from meta-analysis the studies presented only in abstract form and not focused on Mediterranean countries. Of the 311 studies examined, only 6 possessed the criteria for inclusion described above and then considered for the meta-analysis (
Characteristics of the studies included in the meta-analysis for estimate of the concentration of cadmium, lead, and mercury.
Author and year (Ref) | Farms | Area | Farming system | Trace metal | n | Weight in g (mean) | % lipid muscle (mean) | Cd μg g–1 | Pb μg g–1 | Hg μg g–1 (mean ± SD) |
(mean ± SD) | (mean ± SD) | |||||||||
Farm 1 | Greece | – | Cd–Pb | 3 | 224 | 5.2 | 0.054 ± 0.014 | 0.206 ± 0.04 | – | |
Farm 1 | Aegean coast of Turkey | Sea cages | Cd–Pb | 12 | 380.4 | – | 0.06 ± 0.006 | 0.18 ± 0.01 | – | |
Farm 2 | Aegean coast of Turkey | Sea cages | Cd–Pb | 12 | 370.2 | – | 0.08 ± 0.004 | 0.24 ± 0.026 | – | |
Farm 3 | Aegean coast of Turkey | Sea cages | Cd–Pb | 12 | 361.8 | – | 0.02 ± 0.002 | 0.16 ± 0.006 | – | |
Farm 4 | Aegean coast of Turkey | Sea cages | Cd–Pb | 12 | 349.7 | – | 0.04 ± 0.002 | 0.14 ± 0.002 | – | |
Farm 3 | Ria formosa—coastal lagoon in the South Europe | – | Cd–Pb | 7 | 221.7 | 18.6 | 0.00074 ± 0.001 | 0.0138 ± 0.004 | – | |
Farm 4 | Ria formosa—coastal lagoon in the South Europe | – | Cd–Pb | 6 | 453 | 7.8 | 0.00048 ± 0.005 | 0.008 ± 0.002 | – | |
Farm 1 | Italy | Extensive | Hg–Pb | 3 | 468; 708 | – | 0.065 ± 0.078 | 0.025 ± 0.009 | ||
Farm 2 | Italy | Intensive inland basins | Hg–Pb | 9 | 468; 708 | – | 0.11 ± 0.103 | 0.006 ± 0.006 | ||
Farm 3 | Italy | Intensive sea cages | Hg–Pb | 6 | 468; 708 | – | 0.022 ± 0.049 | 0.003 ± 0.004 | ||
Farm 1 | northwestern Mediterranean Sea—Porto Venere (Italy) | floating cages in the sea—in-shore installation | Hg | 25 | 350–450 | – | – | 0.036 ± 0.003 | ||
Farm 1 | Aegean Sea and the Sea of Crete | – | Cd–Pb–Hg | 44 | 403.5 | – | 0.001 ± 0.022 | 0.056 ± 0.094 | 0.047 ± 0.038 |
A dataset for each contaminant was constructed giving the following variables:
identification number of the study (doi, PubMed code, etc.);
author and year of publication; and
year of the study;
for each study, relative to the farmed sea bass:
country where the sea bass is farmed;
detail of farming area;
type of farming;
weight of fish (mean and standard deviation or standard error);
percentage lipid in the muscle (mean and standard deviation or standard error);
number of samples evaluated; and
the contaminant concentration (mean and standard deviation or standard error) into the muscle.
All selected studies have outcome with comparable measures and, for this reason, we used the “mean” of concentrations.
In relation to our paper, where we wanted to calculate the overall mean concentration and standard deviation of concentration observed in all of the studies together, we performed that written by
The literature research was conducted by two investigators (RA and AC) independently. Two authors (RA and AC) selected potentially eligible studies for inclusion independently. Disagreements between reviewers were resolved by consensus; when no agreement was reached, a third author (CDB) was selected for the final decision.
Six studies reported the concentration of Cd and/or Pb and/or Hg in farmed sea bass: four of these allowed a meta-analytical assessment for Cd (
Only total mercury (T-Hg) was determined, and Hg levels were expressed as wet weight. The Cd and Pb levels expressed as dry weight (d.w.) were converted to wet weight (w.w.), using the formula reported by
A random-effects model was used to estimate the summarized effect size, assuming heterogeneity always exists. We used a test for heterogeneity to examine the null hypothesis that all studies are evaluating the same effect. The heterogeneity may be attributed to several factors: characteristics of the population (clinical heterogeneity), study design (type of design, selection procedures, data collection methods) (methodological heterogeneity), and different statistical methods (statistical heterogeneity). In the presence of heterogeneity it may not be appropriate to combine results. To verify the presence of heterogeneity, Cochran’s Q test is usually used. In this test, the null hypothesis is that all studies share a common effect size. Under the null hypothesis, Q will follow a central chi-squared distribution with degrees of freedom equal to k - 1, so we can report a p-value for any observed value of Q (
I2 = 100% × (Q - df)/Q, where Q is Cochran’s heterogeneity statistic and df the degrees of freedom.
I2 is expressed as a ratio with a range of 0–100%; it is not directly affected by the number of studies in the analysis, it is a measure of the degree of inconsistency in the studies’ results, and it reflects the percentage of total variation across studies due to heterogeneity (
In the random effect model, the differences observed in the studies are attributed both to random and differences between the populations studied or related to the characteristics of the individual studies (study variability and variability between studies). Under the random-effects model, we allow that the true effect could vary from study to study. In a random-effects meta-analysis, we usually assume that the true effects (θi) are normally distributed. To compute a study’s variance under the random-effects model, we need to know both the within-study variance and τ2 (tau-squared), where τ2 is the between-studies variance (the variance of the effect size parameters across the population of studies) (
If
that is, the sum of the products (effect size multiplied by weight) divided by the sum of the weights.
The observational nature of the studies used to the meta-analysis did not permit any method of the methodological quality assessment (i.e., about the risk of bias in individual studies or by studies or other quality elements).
A comparative analysis between the concentration of trace metal in meta-analysis and IZSSi’s screening was conducted with Student’s
Statistical analysis was performed using the software SAS 9.4 (Statistical Analysis Software 9.4, SAS Institute Inc., Cary, North Carolina, United States) and R Statistical Software (version 4.0.3; R Foundation for Statistical Computing).
The risk evaluation regarding the presence of trace metals in fish products was carried out on the basis of EFSA’s indexes and the US Environmental Protection Agency (US EPA) method [target hazard quotient (THQ)]. In particular, we used:
(I) EFSA’s indexes:
Provisional tolerable weekly intake (PTWI).
PTWI estimates the maximum amount per unit body weight of a potentially harmful substance or contaminant in food or water that can be ingested weekly without risk of adverse health effects. The PTWI for each trace metal was fixed following a joint study between FAO/WHO Expert Committee on Food Additives (
PTWI Cd: 2.5 μg/kg—body weight (neurotoxicity, nephrotoxicity, carcinogenic, etc.);
PTWI Pb: 25 μg/kg—body weight (neurotoxicity, nephrotoxicity, etc.);
PTWI Hg: 4 μg/kg—body weight (neurotoxicity, nephrotoxicity, carcinogenic, teratogenic, etc.).
The assessment of exposure to trace metals (Cd, Pb, and Hg) is calculated using the estimated weekly intake (EWI) (
where:
Cm = trace metal concentration;
WFC = weekly food consumed;
BW = average body weight (70 kg).
The EWI calculation was carried out considering the Italian per capita weekly consumption (WFC = 9.83 g/week) (
The EWI was also compared with the PTWI of each metal and expressed as a percentage (
(II) US EPA index:
THQ, calculated by the formula:
where EF is exposure frequency (365 days/year); ED is the exposure duration (80 years), equivalent to the average lifetime; FIR is the per capita weekly consumption of farmed sea bass for Italian population (1.40 g/day person) (
At first, 311 potentially eligible articles were retrieved (73 in Medline, 229 in Scopus, and 9 in other source,
Meta-analysis for Cd (
Meta-analysis for Pb (
Meta-analysis for Hg (
The main objectives of the selected studies were different from our aim:
In
In
In
In
In
In
A total of 108 sea bass were involved in meta-analysis of the concentration of Cd, 126 in meta-analysis of the concentration of Pb, and 87 in meta-analysis of the concentration of Hg.
A random-effects model was used to estimate the summarized effect size, assuming heterogeneity always exists. Random-effects model considers both within- and between-study variations for the observed heterogeneity between studies (
Forest plot of meta-analysis of concentration of
The meta-analysis data, representative of various regions in the Mediterranean Sea, have demonstrated the poor contamination by trace metals of sea bass farmed in the Mediterranean area.
In IZSSi’s screening, a total of 16 fish samples of farmed sea bass were bought not alive by randomly selecting some supermarkets in Sicily: 10 sea bass samples came from farms located in Greece (FAO 37.3), and 6 sea bass came from farms located in Malta (FAO 37.2). The mean weight ± SD of farmed sea bass was 390.6 ± 16.2 g.
Cd was detected (>LOD) in three samples (18.8%), Pb in six (37.5%), while Hg was detected < LOD in all samples. With respect to Cd, mean measured concentration (>LOD) was 0.22 ± 0.028 μg g–1, while with respect to Pb, mean measured concentration (>LOD) was 0.014 ± 0.007 μg g–1. For the undetected metals in fish samples, LOD/2 was imputed for purposes of the statistical analysis. The small sample size did not allow the comparison between sea bass samples that came from farms located in Greece and sea bass samples that came from farms located in Malta.
The IZSSi’s screening results showed that the estimates of the concentrations of Cd and Pb were in agreement with the meta-analysis data. To be more specific, the estimate of Cd by meta-analysis was lower than screening (0.031 μg g–1 w.w. for meta-analysis and 0.042 μg g–1 w.w. for screening), but the difference was not statistically significant (
In any case, the results obtained by meta-analysis and by screening were lower than the pre-established legal limits for each metal (
Concentrations of trace metals (Cd, Pb, and Hg) in muscle tissue of farmed sea bass.
Trace metal | Analysis | N | Mean | Standard deviation | CI 95% | Legal threshold of trace metals in fish muscle (mg kg–1 wet weight) | ||
Lower limit | Upper limit | EC/EU* | FAO/WHO** | |||||
Cd | Meta-analysis | 108 | 0.031422 | 0.005006 | 0.022 | 0.041 | 0.050 | 0.50 |
Screening | 16 | 0.041656 (MB) | 0.086545 | 0.0413 (LB) | 0.0421 (UB) | |||
Pb | Meta-analysis | 126 | 0.109931 | 0.025859 | 0.059 | 0.161 | 0.30 | 0.20 |
Screening | 16 | 0.006938 (MB) | 0.006805 | 0.0051 (LB) | 0.0088 (UB) | |||
Hg | Meta-analysis | 87 | 0.023099 | 0.009521 | 0.005 | 0.042 | 0.50 | 0.50 |
Screening | 16 | 0.025 (MB) | 0 | 0 (LB) | 0.05 (UB) |
The results shown in
Estimated weekly intakes (EWIs and EWIs compared to PTWIs) and target hazard quotients (THQs) for individual metals (Cd, Pb, and Hg) by consumption and concentrations observed in meta-analysis and screening of farmed sea bass.
Trace metal | Estimated EWI (mean) | Consumptions g/w* | Concentration (μg g–1 w.w.) | EWI (μg kg–1 bw week–1) | THQ |
Cd | Meta-analysis | 9.83 g/w | 0.031 | 0.004 (0.174% PTWI) | 0.0006 |
Screening IZSSi | 9.83 g/w | 0.042 | 0.006 (0.235% PTWI) | 0.00082 | |
Pb | Meta-analysis | 9.83 g/w | 0.110 | 0.015 (0.062% PTWI) | 0.00055 |
Screening IZSSi | 9.83 g/w | 0.007 | 0.001 (0.004% PTWI) | 0.000035 | |
Hg | Meta-analysis | 9.83 g/w | 0.023 | 0.003 (0.084% PTWI) | 0.0048 |
Screening IZSSi | 9.83 g/w | 0.025 | 0.004 (0.088% PTWI) | 0.005 |
Similar values were found in both the results obtained by meta-analysis and screening, especially for Hg (0.084 and 0.88% of PTWI). Also for Cd, the difference were minimal (0.174 and 0.235% of PTWI), whereas the differences for Pb were marked (0.062 and 0.004% of PTWI). However, the weekly intake of each trace metal was minimal compared with the PTWI.
The results of this work showed a negligible health risk for consumers related to the consumption of farmed sea bass. The comparison with PTWI showed values largely below critical levels, almost insignificant. Even the calculation of THQ revealed very low values, giving a range of 0.000035 and 0.005, up to 28,000 times lower than the values considered safe by the US EPA (0.1). As confirmed by
The results showed that the intake of Cd is particularly high in vegetables (EWI = 1.67 μg kg–1 bw week–1,
Estimated weekly intakes (EWIs and EWIs compared to PTWIs) and target hazard quotients (THQs) for trace metals (Cd, Pb, and Hg) by consumptions and concentrations for different foods.
Trace metal | Food | Consumptions g/w | Concentration (μg g–1 w.w.) | EWI (μg kg–1 bw week–1) | THQ |
Cd | Cereal and cereal products* | 1,897 | 0.023 | 0.626 (25% PTWI) | 0.089 |
Meat and meat products, etc.* | 966 | 0.097 | 1.344 (53.8% PTWI) | 0.191 | |
Vegetables, nuts, etc.* | 1,743 | 0.067 | 1.668 (66.7% PTWI) | 0.238 | |
Sea bream | 9.82** | <0.003–0.022*** | <0.00043–0.00309 (LB-UB) (0.01% PTWI–0.12% PTWI) | <0.00006–0.0004 | |
Pb | Cereal and cereal products* | 1,897 | 0.028–0.047 | 0.775–1.276 (LB-UB) (3.1–5.1% PTWI) | 0.027–0.046 |
Meat and meat products, etc.* | 966 | 0.253–0.273 | 3.496–3.772 (LB-UB) (13.99–15.09% PTWI) | 0.125–0.135 | |
Vegetables, nuts, etc.* | 1,743 | 0.073–0.092 | 1.827–2.298 (LB-UB) (7.31–9.19% PTWI) | 0.065–0.082 | |
Sea bream | 9.82** | 0.013–0.139*** | 0.0018–0.0195 (LB-UB) (0.0073–0.078% PTWI) | 0.00007–0.0007 | |
Hg | Cereal and cereal products* | 1,897 | 0.002 | 0.054 (1.4% PTWI) | 0.077 |
Meat and meat products, etc.* | 966 | 0.002 | 0.026 (0.7% PTWI) | 0.039 | |
Vegetables, nuts, etc.* | 1,743 | 0.007 | 0.174 (4.4% PTWI) | 0.249 | |
Sea bream | 9.82** | 0.12*** | 0.017 (0.42% PTWI) | 0.024 |
The aim of this study was the assessment of the risk of trace metals exposure related to the consumption of farmed sea bass consumed in Italy focusing on three trace metals (Cd, Pb, and Hg). This assessment was performed with a systematic review of the scientific literature concerned sea bass farmed in Mediterranean countries, a meta-analysis of data of the selected literature, screening data from farmed sea bass samples marketed in Sicily, and finally a risk evaluation on the basis of EFSA’s indexes and US EPA method (THQ).
To the best of our knowledge, this was the first study based on meta-analytic techniques for the risk assessment of trace metals related to the consumption of farmed sea bass in Italy. It is important to highlight the small number of studies selected for meta-analysis, and this fact implies the need to treat the subject in a more exhaustive way with new studies that could strengthen the conclusions observed so far. On the other hand, despite the small number of studies, often characterized by a very small sample size (only the most recent studies have a larger sample size), and despite the heterogeneity of the objectives of the selected studies, the results of this work are not discordant. This enables to consider the information of the selected studies very reliable, and consequently, the results of meta-analysis can be a good synthesis of values of concentration of Cd, Pb, and Hg in Mediterranean farmed sea bass.
Several studies indicated that the concentration of trace metals in fish was influenced by various factors such as seasonal and biological differences (species, size, dark/white muscle, age, sex, and sexual maturity), food sources, and environment (water chemistry, salinity, temperature, contaminants, etc.) (
Our results observed in the screening data are in agreement or comparable with the recent literature on Cd, Hg, and Pb concentrations in the muscle tissues of farmed sea bass, collected from various regions in the Mediterranean Sea (
This work allowed us to make some observations on the comparison between farmed and wild bass. The Cd levels observed in the screening data of this work are surely lower than what was found by
The 2020 edition of The State of World Fisheries and Aquaculture continues to demonstrate the significant and growing role of fisheries and aquaculture in providing food, nutrition, and employment (
The traditional fish supplies have plateaued, and as such, modern aquaculture has become the most plausible means of meeting the gap in food fish supplies for the growing population (
While captured fisheries will remain relevant, aquaculture has already demonstrated its crucial role in global food security, with its production growing at 7.5% per year since 1970 (
Moreover, people are focused on the risk of exposure to trace metals through fish consumption, while the risk inherent to other food items is real and more relevant. Indeed, considering our results regarding dietary exposure to trace metals in various food, it is evident that the consumption of products of the Mediterranean diet (cereals and cereal products, meat and meat products, and vegetables) has a greater impact (in terms of EWI, % of PTWI, and THQ) than the consumption of farmed sea bass, taking into consideration the concentration of trace metals and the quantity of product consumed weekly.
Fish and seafood products contain nutrients beneficial for human health, such as omega-3 fatty acids, vitamins, and minerals (
The results of the meta-analysis as well as the results of the selected literature and the results of screening and results with regard to dietary exposure (in term of EWI, % of PTWI, and THQ) suggest that a possible increase in per capita consumption of farmed sea bass would not lead to an increase in risk. Dietary exposure to trace metal cannot be attributed only to fish but is a result of consumption of various food (
By contrast to other studies based on fish consumption, this work took into account exclusively the sea bass Italian consumption rate (
It is also clear that there is in the literature a non-conformity of the data, in particular, in relation to the characteristics of the sample and in relation to the methods used for the determination of trace metals. In this regard, we used a conversion (
The results obtained make it necessary to start epidemiological studies on wild and farmed fish to assess the health risks associated with these chemical and biological contaminants. Indeed, it is very important to reliably estimate the risk through fish consumption considering all factors that influence the concentration of trace metals in fish (seasonal and biological differences, food sources, and environment), although this would involve a complex study design with sample sizes much larger than those present in the scientific literature today. Risk evaluation for consumers performed by
The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation, to any qualified researcher.
Ethical review and approval was not required for the animal study because this study involving farmed sea bass marketed in Sicily. Sea bass were bought not alive by randomly selecting some supermarkets in Sicily.
CD, AC, and RA made substantial contributions to the conception and design of the study and conducted the specific bibliographic research for meta-analysis. CD, AC, RA, and GC drafted and critically revised the manuscript for its intellectual content, gave final approval of the version to be published, and agreed to be accountable for all aspects of the work. AC, GC, DL, VC, LB, GB, VF, and GL made substantial contributions to the fishes chemical analyses and data acquisition. CD, AC, PS, GB, SS, IT, and RA worked to preliminary bibliographic research. RA was responsible for statistical analysis. CD coordinated and supervised all the phases of the study and the drafting of the article. All authors read and approved the final version of the manuscript, contributed to the article, and approved the submitted version.
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
We wish to thank the colleagues involved in the scientific collaboration among the Istituto Zooprofilattico Sperimentale della Sicilia (IZSSi), the Institut National des Sciences et Technologies de la mer-Tunisia (INSTM), and the Direction Générale des Services Vétérinaires-Tunisia.
The Supplementary Material for this article can be found online at: