Kabaran et al. 2020 — Heavy metals in Northern Cyprus olive oil and health risk assessment
This study determined concentrations of Cr, Co, Ni, As, Cd, Pb, Fe, Cu, and Zn in 27 natural olive oil samples from Morphou and Lefka (Northern Cyprus) by ICP-MS, and paired them with a dietary intake survey of 500 adults to calculate Daily Intake of Metal (DIM) and Health Risk Index (HRI). All HRI values were below 1 for all metals, indicating no significant non-carcinogenic health risk to the local adult population from olive oil consumption at observed concentrations and dietary intake levels. The study is noteworthy for using individually measured body weights and dietary intakes rather than assumed population averages, and for its Cyprus-specific geographic relevance to the Paleo Foundation (which operates from Cyprus).
Key numbers
Heavy metal concentrations in natural olive oil from Morphou/Lefka, Northern Cyprus (mean ± SD, ng/mL, n=27):
- Cr: 123.83 ± 44.70 (range: 50.81–217.96 ng/mL = 50.81–217.96 µg/kg)
- Co: 0.81 ± 2.20 (range: nd–12.17)
- Ni: 30.18 ± 9.77 (range: 11.87–53.84)
- As (total): 0.87 ± 1.46 (range: nd–7.39)
- Cd: 1.53 ± 2.02 (range: nd–6.98)
- Pb: 27.72 ± 28.77 (range: nd–126.32)
- Fe: 875.06 ± 806.85 (range: 74.90–4,248.76) [wide variance; attributed to iron/pyrite mineralization of Troodos Mountain deposits in Northern Cyprus]
- Cu: 7.85 ± 13.54 (range: nd–49.14) [below IOC limit of 0.1 mg/kg = 100,000 ng/mL]
- Zn: 469.36 ± 312.86 (range: nd–1,131.89)
All values in ng/mL, which equals µg/kg (ppb) for oils at approximately unit density.
Health risk assessment results (n=500 adults, average olive oil consumption 27.59 ± 15.93 g/day):
- Average body weight: men 86.9 ± 16.48 kg; women 67.7 ± 13.51 kg
- DIM (mg/kg BW/day) and HRI for all metals were well below 1:
- Pb: DIM 1.07 × 10⁻⁴; HRI 3.07 × 10⁻² (highest HRI, against RfD of 0.025 mg/kg BW/day)
- Cr: DIM 4.77 × 10⁻⁵; HRI 2.26 × 10⁻²
- Ni: DIM 1.17 × 10⁻⁴; HRI 5.58 × 10⁻³
- Cd: DIM 5.93 × 10⁻⁶; HRI 5.93 × 10⁻³
- As: DIM 3.37 × 10⁻⁶; HRI 1.12 × 10⁻³
Contextual comparisons cited by authors:
- Cd in Sicilian olive oils: <1.2 ng/g
- Pb in various studies: considerably below MRL of 0.01 µg/g = 10,000 ppb [note: this is the IOC standard stated in the paper; EU/Codex limit is 0.1 mg/kg = 100,000 ppb]
- The elevated Fe (mean 875 ng/mL) is attributed to the iron, pyrite, and copper sulfide mineralization of the Troodos Mountain deposits; still within the 3.0 mg/kg regulatory limit
Methods
ICP-MS (Thermo Scientific X Series II) with CEM Mars 5 closed microwave digestion (1200 W, 200°C, 800 psi, 15 min hold). CRM validated (109469 Multi-element Standard II Oil Dissolved). Calibration curves at six concentrations; each analysis performed in triplicate. Units reported as ng/mL (equivalent to µg/kg for near-unit-density oils). Dietary intake survey: food frequency questionnaire (FFQ), face-to-face, n=500 adults aged 30–49 in Morphou and Lefka districts. Body weight measured directly (TANITA BC420 MA). Ethics approved by Hacettepe University Ethics Committee (17.04.2014, decision no 431-1391). Health risk parameters: RfD values from US-EPA IRIS (Cd, Ni, Cr, As) and JECFA (Fe, Cu, Zn, Pb); DIM and HRI formulas from EPA non-cancer health assessment framework.
Implications
Certification: Cyprus-produced natural olive oil shows Cd and Pb concentrations well within permissible limits at the observed dietary intake levels. The extremely high Fe variability (range 74.9–4,248.8 ppb) deserves attention as a processing quality indicator independent of toxicity; Fe accelerates oxidative degradation. The geographic note that Cyprus’s mineral geology elevates Fe and Cu in local oils is an important supply-chain context for Cypriot-origin olive oil specifications.
Courses: This paper is the first health risk assessment for olive oil in Northern Cyprus, making it geographically specific to the Paleo Foundation’s jurisdiction. The methodology (paired dietary survey + analytical measurement + DIM/HRI calculation) is a good teaching case for how product-level and dietary-level assessments are integrated.
App: Pb (mean 27.72 ppb, max 126.32 ppb) and Cd (mean 1.53 ppb, max 6.98 ppb) in Northern Cyprus natural olive oil are both low and well within safe ranges. These values are appropriate as geographic priors for Cypriot olive oil in the app’s ingredient contamination model.
Speciation caution: As is reported as total arsenic (75As isotope). No speciation into iAs vs. organic forms was performed.