Health risk assessment of heavy metals in root and fruit vegetables in Iran using Monte Carlo simulation

Overview

Mohammadi and colleagues measured lead (Pb), cadmium (Cd), total chromium (Cr), and nickel (Ni) in carrots and cucumbers collected across seven Fars Province sampling points in Iran, then used those concentrations in deterministic and Monte Carlo dietary-risk calculations. The source reports carrot concentrations higher than cucumber concentrations for all four metals, with carrot Pb averaging 0.303 mg/kg and carrot Cr averaging 0.654 mg/kg.

Key numbers

All concentrations below are source-reported mean values in mg/kg after the paper’s dry-to-fresh conversion step.

Matrix	Pb	Cd	Cr	Ni
Carrot, across seven sampling points	0.303	0.004	0.654	0.409
Cucumber, across seven sampling points	0.075	0.003	0.175	0.136

Selected sampling-point means from Table 1 show the range of reported values:

Matrix and site	Pb	Cd	Cr	Ni
Carrot SP1	0.295	0.003	0.715	0.356
Carrot SP2	0.325	0.004	0.682	0.472
Carrot SP7	0.319	0.003	0.662	0.391
Cucumber SP1	0.109	0.002	0.211	0.152
Cucumber SP4	0.092	0.002	0.192	0.146
Cucumber SP6	0.046	0.003	0.201	0.137

The paper reports total metal sums of 1.296-1.483 mg/kg in carrots and 0.343-0.474 mg/kg in cucumbers. It cites comparison limits of 0.1 mg/kg Pb, 0.05 mg/kg Cd for cucumber, 0.1 mg/kg Cd for carrot, 0.5 mg/kg Cr, and 1.5 mg/kg Ni; carrot Pb and carrot Cr exceeded those cited limits, while cucumber means were below them.

For risk outputs, the paper reports non-carcinogenic HI values of 8.20E-03 for carrots and 2.31E-03 for cucumbers, both below 1.0. It also reports carcinogenic-risk values, but the abstract and later text do not match; see Verification notes.

Methods (brief)

Carrot and cucumber samples were purchased from supermarkets in seven cities in Fars Province, Iran. Samples were washed under domestic-style conditions, dried, ground, digested with nitric acid, and measured by ICP. The source states that measured dry-weight concentrations were converted to fresh-weight values using each sample’s moisture content. Risk calculations used Iranian vegetable-consumption assumptions and a 1000-iteration Monte Carlo simulation in Excel.

Implications

Certification: Adds Iran-market carrot and cucumber occurrence data for Pb, Cd, total Cr, and Ni. These are non-US market data and should support context or sensitivity checks unless a benchmark pool explicitly admits Iran-market samples.
Courses: Good example of basis handling because the analytical workflow begins with dried samples but the published occurrence values are converted to fresh-weight vegetable concentrations.
App: Contributes separate concentration rows for Carrot and Cucumber rather than a pooled vegetable-only result.

Update history

No substantive edit history is available in this build. The full commit record is available in git.