Total Mercury and Fatty Acids in Selected Fish Species on the

Overview

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analyzed fish ranged from 0.024 (lake trout) to 0.092 mg/kg wet weight (gilthead seabream). The
invertebrates and algae (29). Next to fish, vegetable oils (rapeseed or canola), linseed or
kidney beans and dry fruits are the main dietary sources of n-3 PUFAs. Vegetable oils
Tench (Tinca tinca Linnaeus, 1758) (n = 6);
Lake trout (Salvelinus namaycush Walbaum, 1792) (n = 6);
Crucian carp (Carassius carassius Linnaeus, 1758) (n = 6);
described in the previous publication (32). The detection limit (LOD) was 0.02 µg/kg,
rate of Hg was 100.2% (n = 4).
was 3.00 × 10−4 mg/kg/day.
where FA is the fatty acid (g/100 g muscles of fish); P is the fatty acid (% of total lipids); FC is
reference dose of metal (3.00 × 10−4 mg/kg/day); HQ is the hazard quotient; AW is an
FLQ = 100 × (EPA + DHA)/(% of total fatty acids) (10)
(p < 0.05) (Table 1). The muscles of lake trout contained the lowest content of mercury, but
Table 1. Differences (x ± SD) in the content of mercury (mg/kg wet weight) in muscle tissue of fish
X—mean; SD—standard deviation; a, b, c —significant differences (p ≤ 0.05). The same letter indicates the absence
of significant differences h (p > 0.05). RfD—oral reference dose (mg/kg/day) (34); THQ—target hazard quotient;
The THQ and HI of individual foodstuff were below 1 and ranged between 0.0473 (lake
3.3. The Differences between Profile of Fatty Acids (%) and the Lipid Quality Indices in Muscles of
The saturated fatty acids (SFAs) varied between 13.78% (lake trout) and 32.17% (tench).
fatty acid in this group as it had sixteen carbon atoms (Table 2).
Figure 1. The percentage of fatty acid groups in the total fat composition of fish examined (%).
tissue of tench (26.62%) and other fish examined (36.89–43.90%) (p < 0.05), whereas in the
and crucian carp; 24.09 and 21.03%, respectively) had the higher values of n-3 PUFAs than
observed in the muscles of mackerel (3.17%) compared to other fish (p < 0.05), whereas
of crucian carp (7.71%; p > 0.05) (Figure 1). Arachidonic acid (C20:4 n-6) and linoleic acid
except in the muscles of lake trout and crucian carp (Table 2). The n-3/n-6 ratio in the
Table 2. Lipid content (%) and fatty acid composition (% of total fatty acids) in muscles of different fish species.
ranged from 10.50 to 24.44 and from 73.93 to 88.61, respectively. In the case of these indices,
(Table 2), and in between 0.762 (crucian carp) and 15.833 (mackerel) mg/g (Figure 2), is The
the Vistula River (Poland) contained more mercury (0.34 mg/kg wet weight) (48) than crucian
carp from this same region (0.14 mg/kg wet weight). Misztal-Szkudlińska et al. (49) found
National Park (west Poland) contained (0.099 mg/kg mercury) three times higher mercury
follows: crucian carp (0.00655 mg/kg) > flounder (0.00393 mg/kg) (p < 0.05) (53). In our
same fish were not found (Table 1). According to Kalisińska et al. (54), mercury content was
belonging to the benthophage group, contained three times more mercury (0.099 mg/kg
wet weight) than the crucian carp examined (Table 1). The frozen muscle tissue of seabream
produced and marketed in Turkey (55) had lower values of mercury (0.0749 mg/kg) than the
seabream we studied (Table 1). Our research found that the mercury content in lake trout
muscles (Table 1) was similar to those in lake trout muscles collected across Canada (56).
mercury level in the muscles of flounder and mackerel examined (Table 1) were not statistically
lower amount of Hg (0.298 mg/kg) than seabream (demersal fish) (0.455 mg/kg) (59).
are consistent with our studies (Table 1). According to above authors, the total mercury

Methods (brief)

were examined. The total mercury (THg) was processed using the Milestone DMA-80 and the fatty
2.1. Sample Collection and Preparation
part with a plastic knife and fork and then thoroughly mixed. The samples were performed
were stored at −30 ◦ C until analysis. Samples were prepared in two parallel replications.
The samples were weighed in two parallel repetitions into quartz boats (approximately
100 mg ± 0.0001 g) and transferred to an analytical autosampler. The total mercury content
was processed using the Milestone DMA-80 (with dual-cell) direct thermal decomposition
mercury analyzer (Italy). The content of mercury was measured in peak area mode against
described in the previous publication (32). The detection limit (LOD) was 0.02 µg/kg,
Total lipids (samples of approximately 1 g ± 0.0001 g) were extracted with the help
petroleum ether. Prior to analysis, duplicate samples were dried to a constant weight at
all of the solvent was collected in the tank. The total lipids were dried in a beaker at 100 ◦ C
The fatty acids of methyl esters of each sample were carried out on the 7890A Agilent
muscles (Table 1) was similar to those in lake trout muscles collected across Canada (56).
M.J.Ł. analyzed the data and collected samples; M.S. contributed to the writing of the “Materials
and arsenic) in fish and shellfish samples. Risk assessment for the consumers. Environ. Int. 2013, 59, 63–72. (CrossRef)

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The five most recent substantive edits to this page, classified major (evidence or structure moved), correction (a published value or statement was wrong and has been fixed), or minor (narrative rewritten without changing the underlying evidence). Each description is derived from what the edit did to this page; the linked commit is the authoritative record, routine regeneration passes are excluded, and the full version history lives in git. When DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.

Commit	Date	Change	Description
b01ec52c	2026-08-04	major	2 sections added
d49e450f	2026-08-03	major	5 sections added; narrative text revised