Levels of Mercury, Methylmercury and Selenium in Fish:

Overview

This source page is a mechanical bulk-ingest record for a PDF in the research-pulls corpus. It preserves source-level identity, routeable product/analyte scope, and exact extracted numeric lines for later human or fresh-context audit. It does not derive HMTc thresholds, percentiles, or brand-by-brand comparisons.

Key numbers

The worker extracted the full PDF text with layout preservation twice and compared extraction hashes before commit. The following lines are copied from numeric/table-bearing regions of the PDF and retain the source units and wording where legible:

Citation: Barone, G.; Storelli, A.; intakes were provided from 0.71% to 2.75% of the RDA. Se:Hg molar ratios above 1 and positive
species (Table 1) were purchased from May 2019 till July 2019 in the main commercial
of samples were conserved in HNO3 solution (10%) overnight and rinsed many times with
Table 1. Nomenclature, total length (min-max and mean ± SD) and trophic levels of the studied
were of pesticide analysis grade and all acids used (nitric acid (65%) (Merk, Darmstadt, Ger-
many), hydrochloric acid (37%) (Carlo Erba, Milan, Italy), sulfuric acid (96%) (Carlo Erba,
dissolving suitable pure quantities in acidified water (HNO3 0.3%), while methylmercury
chloride was obtained from Alfa Aesar, (Heysham, U.K.) (99.4%). Stock solutions were
decontaminated overnight in 10% (v/v) nitric acid solution, and rinsed again.
bath LBS2 (Levanchimica, Bari, Italy). Subsequently, an aqueous solution of NaCl 10%
designed at 240 ◦ C. Helium (99.99%) was used as a carrier gas at a flow rate of 1.0 mL min−1 .
Electron impact ionization was performed with an electron energy of 70 eV. A mass range
tional Research Council of Canada). Replicate analyses (n = 3) (THg 0.289 ± 0.021 mg
(% recovery = 96–101%). The limits of detection (LOD: 3 SD blank value) and of quantifica-
tion (LOQs: 10 SD blank value) are the following: LODs: THg: 5 ng g−1 wet weight, MeHg:
0.03 ng g−1 wet weight, Se: 1 ng g−1 wet weight; LOQs: THg 13 ng g−1 wet weight, MeHg:
As can be seen in Table 2, THg and MeHg concentrations varied widely among
percentage, ranged from a minimum of 66.7% in European anchovy to a maximum of 92.9%
described in Table 2. A wealth of scientific literature describes the adverse neurological
an entire lifetime without any significant risk to human health. As can be seen in Table 2,
3 (Supplemental Table S1). More specifically, children may safely consume 21 meals of
304/9/2/39/s1, Table S1: THg and MeHg concentrations and daily (CRlim) and monthly (CRmm)
1. United States Environmental Protection Agency (US EPA). Risk Based Concentration Table; United States Environmental Pro-tection
1. United States Environmental Protection Agency (US EPA). Regional Screening Level (RSL) Summary Table (TR=1E-06, HQ=1);

Methods (brief)

2.1. Sample Collection
a composite sample was prepared, homogenized, and stored below −20 ◦ C, pending
of samples were conserved in HNO3 solution (10%) overnight and rinsed many times with
2.3.1. Sample Preparation and Equipment
where (20). Briefly, aliquots of samples (about 2 g) were digested to a transparent solution
with a mixture of H2 SO4 –HNO3 (1:1). The sample solution was then cooled and diluted
agencies (32). THg and Se were analyzed by atomic absorption spectrophotometer (Shi-
by Ipolyi et al. (33) was followed. Aliquots of the samples (about 0.5 g) were washed with
and the sample added of ethylmercury chloride in methanol (100 µL internal standard),
(w/v) was added to the sample, and the mixture was centrifuged (2400 rpm for 10 min).
cation of the collected cysteine extract with H2 SO4 (0.1 M), the derivatization reaction was
µL of the sample was injected in splitless mode at an injection temperature of 250 ◦ C. The
(% recovery = 96–101%). The limits of detection (LOD: 3 SD blank value) and of quantifica-
tion (LOQs: 10 SD blank value) are the following: LODs: THg: 5 ng g−1 wet weight, MeHg:
0.03 ng g−1 wet weight, Se: 1 ng g−1 wet weight; LOQs: THg 13 ng g−1 wet weight, MeHg:
1. Bjørklunda, G.; Dadarb, M.; Mutterc, J.; Aasethd, J. The toxicology of mercury: Current research and emerging trends. Environ.
selenium and zinc) in fish and shellfish samples. Risk and nutritional assessment and mercury–selenium balance. Food Chem.
1. Ipolyi, I.; Massanisso, P.; Sposato, S.; Fodor, P.; Morabito, R. Concentration levels of total and methylmercury in mussel samples

Implications

This page makes the source discoverable for category-level evidence routing. Values remain source-native and should be used only with the stated matrix, species, basis, geography, and censoring context from the paper. The page does not convert total mercury to methylmercury or use total arsenic as inorganic arsenic.

Wiki pages this source may touch

Verification notes

Identity check: DOI, raw handle, candidate cite-key, and SHA-256 were compared against existing wiki/sources/ pages before creation.
Full-PDF read: pdftotext -layout was run on the full PDF twice; extracted text hashes matched before the page was written.
Numeric verification: numeric/table-bearing lines were selected mechanically from the verified extraction and preserved without unit conversion or rounding.
Brand firewall: the worker skips PDFs when extracted numeric lines appear brand/manufacturer-sensitive; this page contains category-level or species-level evidence only.
HMTc firewall: no threshold, percentile, pass/fail, clean/dirty, or certification math is stated.

Update history

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