Ćwieląg-Drabek et al. 2025 — Cd, Pb, Cr, Ni in five nut types: health risk for Polish consumers
This study measured Cd, Pb, Cr, and Ni concentrations in 69 samples of five nut types (almonds, cashews, hazelnuts, peanuts, walnuts) available on the Polish market using electrothermal atomic absorption spectrometry (ETAAS). Samples originated from 13 countries. All Cd concentrations remained below the EU ML of 0.20 mg/kg for tree nuts and peanuts. One peanut sample (from Poland) exceeded the Chinese Pb limit for peanuts (0.2 mg/kg) at 0.818 mg/kg. Health risk assessment using hazard quotient (HQ) and hazard index (HI) found that consumers with higher nut intake scenarios (particularly children) may face moderate to high non-cancer health risks, primarily driven by Ni and cumulative multi-metal exposure.
Key numbers
Mean concentrations by nut type (mg/kg, wet weight; ETAAS):
| Metal | Peanuts | Almonds | Hazelnuts | Cashews | Walnuts | All nuts mean |
|---|---|---|---|---|---|---|
| Cd | 0.092 | — | — | < LOQ | — | 0.030 |
| Pb | 0.229 | 0.22 | — | < LOQ | — | 0.143 |
| Ni | ~4 | 1.299 | — | 6.434 | — | 3.21 |
| Cr | ~0.23 | 0.253 | — | — | 0.133 | 0.211 |
Elemental ranking: Cd: peanuts > almonds > hazelnuts > walnuts > cashews; Pb: peanuts > almonds > hazelnuts > walnuts > cashews; Ni: cashews > peanuts > walnuts > hazelnuts > almonds; Cr: almonds > cashews and hazelnuts > peanuts > walnuts.
Highest single values: Ni in peanuts 11.20 mg/kg (highest across all studies compared); Pb in peanuts 0.818 mg/kg (single outlier, from Poland, exceeded Chinese ML of 0.2 mg/kg).
Below LOQ rates: Cd 41% of all samples; Pb 49%; Ni 21%; Cr 4%.
LOD: Cd 0.0017 mg/kg, Pb 0.018 mg/kg, Ni 0.27 mg/kg, Cr 0.034 mg/kg. LOQ: Cd 0.0032 mg/kg, Pb 0.032 mg/kg, Ni 0.44 mg/kg, Cr 0.06 mg/kg.
Regulatory context: EU ML for Cd in tree nuts and peanuts = 0.20 mg/kg (Regulation EC 1881/2006); no EU MLs for Pb, Ni, or Cr in nuts. China ML: Cd 0.5 mg/kg, Pb 0.2 mg/kg (peanuts only).
Health risk (HQ/HI): Reference doses (EPA): Cd 0.0010 mg/kg bw/day; Pb 0.0036 mg/kg bw/day; Ni 0.0200 mg/kg bw/day; Cr 0.0030 mg/kg bw/day. At higher consumption scenarios (50–100 g/day) for children, HI > 1 indicating moderate-to-high non-cancer risk, driven primarily by Ni.
Origin effects: For peanuts: Cd highest from China; Pb highest from Poland. For hazelnuts: Cd and Pb highest from Turkey. For cashews with detectable Cd/Pb: all from India samples only.
Methods (brief)
ETAAS (Savant AA Sigma, GBC). Microwave digestion with supra-pure HNO3 in Teflon containers. Recovery: Ni 98%, Cr 107%, Cd 95%, Pb 101%. All samples purchased retail in Poland; 83% pre-packaged; 17% bulk-weighed. n=69 (16 peanuts, 15 hazelnuts, 15 almonds, 8 cashews, 15 walnuts). Speciation not performed; Cr is total chromium.
Note: does not include iAs, tAs, tHg, Al, Sn, or U.
Implications
Certification: Provides recent (2024 data) EU market concentrations for Cd, Pb, Ni, Cr across five major nut types. Ni is the most abundant toxic element in nuts and the primary driver of health risk at high consumption levels. Cashews (mean Ni 6.4 mg/kg) and peanuts (up to 11.2 mg/kg Ni in one sample) are highest-risk for Ni. Cd in peanuts (mean 0.092 mg/kg) is approaching but below the EU ML; geographic origin matters (China > Poland > Argentina). The Cr values represent total chromium; Cr-VI would be lower and cannot be inferred from this data.
Courses: Demonstrates how consumption scenario assumptions (daily intake) dramatically affect health risk conclusions; the 10 g/day scenario yields acceptable risk, whereas 100 g/day for children may not.
App: Origin-tagged concentration ranges for peanuts, almonds, hazelnuts, cashews, walnuts. Use total Ni and Cd ranges; note Pb high detection rate issue for peanuts from Poland (local contamination suspected).