Berber et al. 2024 — Metals and fatty acids in narrow-clawed crayfish, Turkey
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.