Karatasli 2018 — Radionuclides and heavy metals in Turkish Mediterranean table olives

This study determined concentrations of natural and anthropogenic radionuclides (226Ra, 232Th, 40K, 137Cs) and heavy metals (Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Pb) in 26 table olive samples from the Mediterranean region of Turkey, and assessed associated health risks via estimated annual effective radiation dose and daily intake of heavy metals. The author concludes that neither radionuclide nor heavy metal levels in these samples pose health hazards: the average annual effective radiation dose from ingestion was 11 µSv/year (paper reports this as “far below the recommended level of 1000 mSv” — likely a units typo in the paper for 1 mSv = 1000 µSv, but the comparison to the 2400 µSv/year global ingestion average reported elsewhere in the same paper is the more meaningful benchmark), and daily heavy metal intakes were below WHO maximum daily intake recommendations. Notably, cadmium and arsenic — the two analytes most regulated in food safety contexts — were not measured in this study; the heavy metal panel was limited to Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, and Pb.

Key numbers

Heavy metal concentrations in the edible parts (dry weight, µg/g = mg/kg), n = 26 samples (Table 3):

Note on units: values are expressed as µg/g dry weight (= mg/kg dw). The paper applies a dry-to-fresh mass ratio of 0.2 (i.e., approximately 80% moisture in fresh table olives) when computing daily intake. On that conversion, the average Pb of 4.55 mg/kg dw corresponds to approximately 0.91 mg/kg fresh weight; the average Ni of 10.29 mg/kg dw corresponds to approximately 2.06 mg/kg fresh weight.

In comparison with other Turkish olive studies (paper’s literature review): Fe, Zn, Cu, Mn, Ni, Pb, Cr, and Co concentrations measured here are higher than those reported by Sahan et al. (2007, ICP-MS, Bursa), Nergiz et al. (2008), and Tuna (2011). For Pb specifically, Sahan et al. reported 0.57–0.91 µg/g, Nergiz et al. reported 0.09–0.278 µg/g, and Tuna reported 0.25–0.88 µg/g — all roughly an order of magnitude below this study’s 3.88–5.22 µg/g range. The author does not propose an explanation for the systematic offset; differences in cultivar, regional soil/water contamination, processing state, or analytical method could each contribute.

Concentrations in kernels (Table 3) were generally lower than edible parts for Cr (1.91 ± 0.06), Ni (2.24 ± 0.04), Cu (4.58 ± 0.33), Zn (9.09 ± 0.34), and Co (0.17 ± 0.01), but higher for Mn (13.64 ± 0.32), Fe (213.30 ± 6.37), Sr (10.52 ± 0.44), and Pb (4.90 ± 0.09).

Radionuclides in edible parts (Table 1): 226Ra average 37.9 ± 4.1 Bq/kg dw (range 7.6–87.8), 232Th average 7.1 ± 0.5 Bq/kg dw (range 2.7–12.0), 40K average 274.6 ± 14.7 Bq/kg dw (range 158.2–488.3), 137Cs average 7.2 ± 0.7 Bq/kg dw (range 2.0–12.6). 137Cs is below the permitted value of 1,000 Bq/kg.

Daily intake estimates (edible parts, based on 11 g/day consumption and 70 kg adult, Table 5): Cr 0.06 µg/kg bw/day, Mn 0.35 µg/kg bw/day, Fe 5.24 µg/kg bw/day, Co 0.01 µg/kg bw/day, Ni 0.32 µg/kg bw/day, Cu 0.43 µg/kg bw/day, Zn 0.45 µg/kg bw/day, Sr 0.14 µg/kg bw/day, Pb 0.14 µg/kg bw/day — all reported as below WHO maximum daily intake recommendations (paper cites the 1989 41st JECFA report rather than current PTWI/PTMI values).

Annual effective ingestion dose (Table 4): average 11.2 µSv/year for edible parts (range 3.4–22.7) and 5.9 µSv/year for kernels (range 2.0–11.3). The 226Ra contribution dominates (8.5 µSv/year average), followed by 232Th (1.3), 40K (1.4), and 137Cs (0.1).

Methods

Sample collection: 26 table olive samples from 26 distinct districts in Adana, Osmaniye, and Hatay provinces (Mediterranean Turkey). Edible parts separated from kernels. The author does not state whether samples were collected as fresh fruit, cured table olives in brine, or both; the paper’s literature comparison cites studies on both fresh fruit and processed table olives, and the dry-mass conversion factor (r = 0.2 dw/fw, approximately 80% moisture) is consistent with either form.

Sample preparation for heavy metals: EPA Method 3052 closed microwave digestion (0.5 g sample, 9 mL concentrated HNO3 + 4 mL HF + 2 mL HCl + 1 mL H2O2; CEM MARS 5; 1200 W, ramp to 200 °C over 20 min, hold 10 min; followed by boric acid step to retain chloride ions). Digest filtered through Whatman-542 paper and diluted with double-distilled water.

Heavy metal analysis: ICP-OES (PerkinElmer dual-view CCD-array spectrometer, Cekmece Nuclear Research and Training Center), calibrated against PerkinElmer Pure Quality Control Standard 21 (three standard solutions).

Radionuclide analysis: gamma ray spectrometry (Canberra GX3018 coaxial p-type HPGe detector, resolution 1.8 keV at 1332.5 keV for 60Co, 30% relative efficiency, shielded). Samples dried at 110 °C for 3 days, ground, sealed in Marinelli beakers, stored 2 months to reach secular equilibrium of 226Ra/232Th and progeny. 226Ra measured via 351.9 keV (214Pb) and 609.3 keV (214Bi) lines; 232Th via 911.2 keV (228Ac) and 583.2 keV (208Tl); 40K and 137Cs measured directly at 1460.8 and 661.8 keV respectively. Detection limits 1.3, 1.4, 8.6, and 1.5 Bq/kg for 226Ra, 232Th, 40K, 137Cs respectively.

Key limitation: cadmium and arsenic — the two analytes most central to food contaminant surveillance — were not measured. The heavy metal panel reflects the study’s framing around general nutritional/radiological safety rather than HMI-relevant contaminant occurrence. Fe, Cu, Mn, and Zn ranges are in the essential-mineral nutrition range, not the contaminant-monitoring range.

Basis: dry weight throughout. Fresh-weight conversions require the 0.2 dw/fw ratio stated in the paper.

Implications

Certification: The most HMTc-relevant analyte measured here is Pb. The average Pb of 4.55 mg/kg dw (≈0.91 mg/kg fw using the paper’s 0.2 dw/fw ratio) is roughly an order of magnitude above the Pb concentrations reported in other Turkish olive studies (Sahan et al. 0.57–0.91, Nergiz et al. 0.09–0.278, Tuna 0.25–0.88, all µg/g dw — so 0.11–0.18 mg/kg fw at the upper bounds). Whether this Karatasli value represents a real geographic/processing difference, sample contamination during digestion (HF + HCl + HNO3 acid mixture can introduce Pb if reagents are not ultra-pure), or an analytical-method artifact is not resolvable from this paper alone. The Pb data here should not be treated as a single representative occurrence value for Mediterranean Turkish table olives without corroboration. Cd and tAs were not measured, so this paper does not contribute to those two HMTc-critical analyte distributions.

Courses: This paper is a useful teaching example of a published heavy-metal occurrence study whose analyte panel was chosen for nutritional/radiological framing rather than food-safety surveillance, and whose Pb values sit roughly 10× above the geographically nearest comparable studies without an explanation in the discussion. Both features are common in the food-radioactivity literature and worth flagging when synthesizing across studies.

App: The Pb range (3.88–5.22 mg/kg dw ≈ 0.78–1.04 mg/kg fw) and Ni range (2.92–17.67 mg/kg dw ≈ 0.58–3.53 mg/kg fw) are the contaminant-relevant numbers from this paper. They should be carried into any per-serving estimator with the explicit caveat that they are roughly an order of magnitude above other Turkish olive studies in the same period and have not been independently corroborated.

Verification notes

• 2026-05-28: Merge-enhanced from 2026-05-14 ingest. Corrected legacy raw_handle (manual-fetch-kimi → MFK_radionuclide-and-heavy-metal-content-in-the-table-); restored truncated raw_path (was Radionuclide and heavy metal content in the table olive (Olea eur.pdf; now full filename); added raw_sha256 (d49b1f296b2189222c381216ad52ff6127439cd1318aff59372cb8a606556fb1) and access_url.
• 2026-05-28: Verified all heavy metal averages, ranges, and standard deviations against Table 3 of the paper (edible parts and kernels). Verified radionuclide averages against Tables 1 and 2. Verified daily intake values against Table 5 and AED values against Table 4. No transposition errors found in the prior page’s Key numbers table.
• 2026-05-28: Removed the unverified-in-wiki “EU limit for Pb in table olives is 0.10 mg/kg fw per Commission Regulation 2023/915” claim. The wiki currently has regulations/eu-2023-915-lead-infant-young-child-foods (specific to infant/young-child products) and regulations/eu-2023-915-cadmium (specific to cadmium), neither of which document the table-olive Pb limit. EU 2023/915 does set Pb limits for many fruit and vegetable categories, but without a wiki regulation page documenting the table-olive value, the specific 0.10 mg/kg fw number should not be asserted here. The corresponding [[regulations/eu-2023-915]] wikilink at the bottom of the prior page pointed to a non-existent regulation slug and has been removed.
• 2026-05-28: Removed the “Flag for cross-check against EU 2023/915 table-olive Pb limit” implication-list instruction. Replaced with a declarative discussion of the Pb result’s magnitude versus other Turkish olive studies, which is the substantive observation in either case.
• 2026-05-28: Added explicit comparison values for Pb from Sahan et al., Nergiz et al., and Tuna (paper’s literature review), so the ~10× discrepancy this study reports is on the page rather than implied.
• 2026-05-28: Added daily intake values for all 9 measured metals (prior page listed only Pb, Ni, Cr) and the AED breakdown by radionuclide (prior page omitted), both directly from Tables 4 and 5.
• 2026-05-28: Added kernel-vs-edible-parts contrast values for completeness.
• 2026-05-28: Noted the paper’s “1000 mSv” conclusion-section comparison appears to be a units typo (1 mSv = 1000 µSv would be consistent with the 2400 µSv/year ingestion comparison the same paper makes earlier); reported as the paper writes it but flagged the inconsistency.
• 2026-05-28: Audit subagent (fresh-context) flagged the products: ["[[products/non-root-vegetables]]"] routing as a slug-vocabulary error on the grounds that table olives are a cured drupe/fruit and not a vegetable. Finding verified — table olives (Olea europaea L.) are botanically a drupe (stone fruit), and culinarily a cured/preserved food typically eaten as a condiment, side, or garnish, not as a vegetable in any standard food taxonomy. The HMI products taxonomy does not currently have a table-olives or olives product slug, and none of the existing slugs (non-root-vegetables, canned-vegetables, fresh-fruit, dried-fruit, condiments-general, olive-oil) is a clean match. Left as non-root-vegetables for now to preserve the working routing target, and flagging here as a slug-gap proposal for Karen: a products/table-olives provisional scaffold (Step 0 Lock candidate) would be the right long-term routing destination for this paper and the other table-olive papers in raw/Manual Fetch Kimi /condiment_papers/03_Olives_and_Pickles/. Not creating a new product page from this session per task hard constraints.
• 2026-05-28: Audit subagent flagged the wiki narrative’s attribution of “1000 mSv” to the paper as potentially mischaracterizing what the paper actually says. Finding verified — false positive. The paper’s Conclusions (p. 8) explicitly reads “far below the recommended level of 1000 mSv” (not 1000 µSv). The wiki’s “likely a units typo in the paper for 1 mSv = 1000 µSv” gloss correctly characterizes both what the paper writes and the likely intended meaning. No change.

Wiki pages updated on ingest

• olives
• lead
• nickel
• chromium
• iron
• copper
• zinc
• cobalt
• manganese

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.