Hwang 2010 - Metals in Korean dried seaweed

Hwang and colleagues measured total arsenic, total mercury, lead, and cadmium in 426 dried edible seaweed samples sold in Korea during 2007-2008. The study covers laver, brown seaweed, kelp, and sea lettuce, with results reported on a dry-weight basis. Arsenic was measured as total arsenic, not inorganic arsenic.

Key numbers

The study analyzed 426 dried seaweed samples: laver n = 125, brown seaweed n = 153, kelp n = 102, and sea lettuce n = 46. Production-coast counts were east n = 137, west n = 71, and south n = 218.

The abstract reports average concentrations in mg kg−1 dry weight: total arsenic 17.4 (<LOD to 88.8), Hg 0.01 (0.001 to 0.050), lead 0.7 (<LOD to 2.7), and cadmium 0.50 (<LOD to 2.9).

Table 3 reports final-total average concentrations as mg kg−1 dry weight: mercury 0.011 (0.001-0.050), lead 0.703 (<LOD to 2.719), cadmium 0.504 (<LOD to 2.931), and total arsenic 17.382 (<LOD to 88.790).

Table 3 product subtotals report:

The Results text states that mercury in brown seaweed and kelp was statistically higher than in laver and sea lettuce (p < 0.01), and that arsenic in kelp (23.26 mg kg−1) was significantly higher than in the other seaweed types (p < 0.01). It also states that brown seaweed, laver, kelp, and sea lettuce had lead levels of 0.770, 0.710, 0.669, and 0.539 mg kg−1, respectively, without statistically significant product-kind differences for lead.

Table 4 reports intake estimates using 8.5 g day−1 seaweed consumption and Korean standard adult weight. Daily intakes were total mercury 0.014 µg day−1 per capita, lead 5.976 µg day−1 per capita, cadmium 4.284 µg day−1 per capita, and total arsenic 147.747 µg day−1 per capita. Total weekly intakes were total mercury 0.010 µg kg−1 body weight week−1, lead 0.658 µg kg−1 body weight week−1, cadmium 0.472 µg kg−1 body weight week−1, and total arsenic 2.325 µg kg−1 body weight day−1 as a total daily intake comparison.

Table 4 risk indices were total mercury 0.2%, lead 2.63%, cadmium 6.74%, and total arsenic 4.65% of the source-selected tolerable-intake comparator.

Method quality-control values reported trueness from CRMs ranging from 85% to 104%. Average spiking trueness percentages for total arsenic, lead, cadmium, and total mercury were 101% ± 10%, 97% ± 5%, 99% ± 8%, and 105% ± 12%, respectively. The mercury LOD was 0.0047 ng; ICP/OES LODs for lead, cadmium, and arsenic were 0.002, 0.001, and 0.021 µg ml−1, respectively.

Methods (brief)

Samples were purchased as dried material and as coastal-production products from Korean markets, washed with deionized water, dried, and ground to powder. Mercury was measured with a DMA80 Direct Mercury Analyzer following USEPA Method 7473. Total arsenic, lead, and cadmium were measured after microwave digestion using modified USEPA Method 3052 and ICP/OES following USEPA Method 6010B. Quality control used NRC MESS-3 marine sediment, ERM-CE 278 mussel tissue, NIST-SRM 1566b oyster tissue, and IAEA-407 fish homogenate. The study measured total arsenic only; it did not measure inorganic arsenic speciation.

Implications

This source contributes Korean-market dried-seaweed occurrence data for total arsenic, total mercury, lead, and cadmium. It is directly relevant to seaweed-kelp-food routing, but downstream arsenic use must keep the measured tAs values separate from any inorganic-arsenic estimate. The paper’s own discussion notes that total arsenic is not a useful toxicological substitute for inorganic arsenic.

Verification notes

• PDF text extracted with pdftotext -layout; title page, abstract, methods, Tables 1-4, Results, and Discussion were readable.
• DOI 10.1080/19440040903532079, raw handle MFK_hwang2010, and cite-key checks found no existing source page before creation.
• Table 3 concentrations, Table 4 intake values, sample counts, and method LOD/trueness values were checked against extracted text and rendered PDF pages. Units are preserved as mg kg−1 dry weight, µg day−1 per capita, µg kg−1 body weight week−1, µg kg−1 body weight day−1, ng, and µg ml−1; no conversion was performed.
• Speciation: arsenic is total arsenic (tAs) and mercury is total/unspecified Hg (tHg). The paper discusses inorganic arsenic comparator values but does not report measured inorganic arsenic occurrence.
• Brand firewall: no sampled product brand values were reported.
• Frontmatter product and ingredient slugs were checked against docs/gpt-collaboration/taxonomy-snapshot.md; no new slug was invented.

Page history

The five most recent substantive edits to this page. 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.