Overview
This study reports a 12-month monitoring investigation of metal concentrations (Fe, Zn, Al, Cu, Mn, Se, As, Hg, Cd, Pb) and fatty acid profiles in the narrow-clawed crayfish Pontastacus leptodactylus harvested from Atikhisar Dam Lake, Çanakkale Province, Turkey. Crayfish are a commercially harvested freshwater crustacean in Turkey and a food product of regional significance. The study examines seasonal variation and sex-based differences in metal accumulation, and concludes with a health risk assessment (EDI, THQ, cancer risk) for consumers.
Key numbers
- Sampling: monthly over 12 months; separate analysis for male and female individuals
- Analytical method: ICP-MS (for all 10 metals including As and Hg; speciation not performed — total As and total Hg reported)
- Metal summary (representative means, approximate, from text; wet weight):
- Fe: highest concentration of all measured metals; in the hundreds of mg/kg range consistent with crustacean literature
- Zn: elevated; typical for crustaceans
- Al: present; seasonal variation noted
- Cd: detected; concentrations relative to EU limits for crustaceans (0.5 mg/kg wet weight) variable by season
- Pb: detected; concentrations relative to EU limit for crustaceans (0.5 mg/kg)
- Hg: low; below EU limit of 0.5 mg/kg for crustaceans in most samples
- As: total As reported; iAs speciation not performed
- Seasonal variation: significant for several metals; winter and spring sampling showed different patterns from summer
- Sex differences: statistically significant for some metals; females showed higher concentrations for certain elements
- THQ: below 1 for all individual metals at calculated consumption levels; composite target hazard quotient (ΣTHQ) below 10
- Health risk assessment conclusion: no significant non-carcinogenic risk at typical Turkish consumer intake levels
Methods (brief)
ICP-MS analysis of acid-digested muscle tissue; microwave-assisted digestion with HNO3/H2O2; certified reference materials used for QC; LODs reported for each metal. Monthly sampling over a full year to capture seasonal variation. Statistical analysis: ANOVA for seasonal and sex effects. Fatty acid analysis by GC-FID (not directly relevant to heavy metals).
Implications
Certification: Provides a full-year, multi-metal dataset for freshwater crayfish from a Turkish freshwater reservoir. Covers all HMT&C analytes except MeHg (total Hg only) and Cr-VI (total metals only). Useful as a crustacean matrix reference.
Courses: Strong example of seasonal monitoring design; demonstrates how metal accumulation in crustaceans varies by season and sex; illustrates composite risk assessment (ΣTHQ).
App: Crayfish contamination profile for heavy metals; total As and total Hg rather than iAs and MeHg — a methodological limitation for speciation-required analytes.
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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 |
|---|---|---|---|
| a8052bb | 2026-08-09 | major | 6 sections added; narrative text revised |