Abdolahpour Alamdari et al. 2023 — Heavy metals in vegetables from Babol, Iran
This cross-sectional descriptive study measured copper (Cu), zinc (Zn), cadmium (Cd), and lead (Pb) in eight vegetable types grown in Babol city, Mazandaran Province, northern Iran during the 2021 harvest season. The highest mean concentrations of Cd (1.93 mg/kg) and Pb (0.48 mg/kg) — both expressed as fresh weight — were found in parsley and spinach samples, consistent with leafy vegetables accumulating more heavy metals than root vegetables or fruit vegetables. All hazard quotients (HQ) for Cd and Pb were below 1, indicating no non-carcinogenic risk; Zn showed an HQ above 1 for parsley and spinach. Lead and cadmium concentrations in parsley, spinach, and basil exceeded Iran National Standards for leafy vegetables (Pb limit 0.2 mg/kg for leafy; Cd limit 0.05 mg/kg for leafy), while root and fruit vegetables were within standards.
Key numbers
- Sample: 32 samples across 8 vegetable types (parsley, spinach, basil, tomatoes, cucumbers, potatoes, onions, beans); 4 samples per type; fresh-weight basis
- Method: Atomic absorption spectrometry (AAS, model AvantaP, GBC, Australia) after acid digestion (HNO3/HClO4/H2SO4 1:1:5 mixture at 80°C)
- Mean Cd (mg/kg fresh weight): parsley 0.06 ± 0.04, spinach 0.04 ± 0.44, potatoes 0.03 ± 0.01, onions 0.01 ± 0.08, basil 0.032 ± 0.04, tomatoes 0.027 ± 0.022, cucumbers 0.02 ± 0.36, beans 0.01 ± 0.39
- Mean Pb (mg/kg fresh weight): parsley 0.5 ± 0.16, spinach 0.48 ± 0.16, potatoes 0.20 ± 0.18, onions 0.18 ± 0.05, basil 0.16 ± 0.16, tomatoes 0.19 ± 0.43, cucumbers 0.088 ± 0.52, beans 0.067 ± 0.52
- Note: the abstract states “highest mean concentration of cadmium … was 1.93 mg/kg … in parsley and spinach samples,” but the Table 1 values for individual vegetable types are much lower (parsley Cd 0.06 mg/kg). The 1.93 mg/kg figure in the abstract likely represents a maximum in the dataset or a typographic error; Table 1 values are to be preferred for citation of typical concentrations.
- Hazard Index (HQ summed over 4 metals): all study vegetables HI < 1 for Pb and Cd; Zn HQ > 1 for parsley and spinach
- Highest daily Pb intake: spinach, 0.0022 mg/kg/day; highest Cd intake: basil and spinach, 0.0006 mg/kg/day
- Iran National Standards: Pb 0.2 mg/kg (leafy), 0.1 mg/kg (root/fruit); Cd 0.05 mg/kg (leafy), 0.1 mg/kg (tubers)
- Parsley and spinach Pb exceeded Iran National Standard; cadmium concentrations in all vegetables below Iran standard
Methods (brief)
Descriptive cross-sectional study; 4 random samples per vegetable type from Babol agricultural fields at harvest maturity in 2021. Edible parts washed with distilled water, dried at 60–65°C, crushed; 1 g digested in 15 ml tri-acid mixture (HNO3/HClO4/H2SO4, 1:1:5) at 80°C; volume adjusted to 50 ml. AAS with fresh-weight correction from dry matter determination at 105°C for 24 h. EDI calculated for 70 kg adult; HQ = EDI/RfD (Pb RfD 0.0035, Cd 0.001, Cu 0.1, Zn 0.3 mg/kg/day). Statistical analysis in SPSS v16.0. Note: the paper reports Cu and Zn in addition to Pb and Cd, but Cu and Zn are not priority HMT&C analytes; Pb and Cd data are the relevant outputs for this wiki.
Implications
Certification: Pb and Cd values for leafy vegetables (parsley, spinach, basil) from Babol are above Iranian national standards for leafy vegetables but the sample sizes are very small (n=4 per type) and the study area is one city in northern Iran. Values should not be extrapolated to global leafy vegetable baselines without caution. The abstract-vs-table discrepancy for peak Cd (1.93 mg/kg in abstract vs 0.06 mg/kg in Table 1) needs flagging; the table values are internally consistent and cited here.
Courses: Illustrates differential heavy-metal accumulation between leafy vegetables (higher) and root/fruit vegetables (lower); demonstrates how EDI-based HQ can show no risk even when concentrations exceed national standards, depending on per-capita consumption.
App: Use Table 1 values for Pb and Cd by vegetable type. Flag the abstract-vs-table discrepancy for Cd. n=4 per type is a low-confidence basis for contamination profile values; mark confidence as low.
Microbiome: Not applicable.