Comparative mobilization and bioaccumulation of cadmium and lead in apple orchards and associated screening level ecological and human health risks
Year: 2026
Type: article
Abstract: Lead (Pb) and cadmium (Cd) accumulate in agricultural soils through long-term agrochemical use, posing ecosystem and food-safety risks; whether these inputs elevate Pb and Cd in edible fruit had not previously been quantified for Iranian apple orchards. This screening-level, multi-index study assessed Pb and Cd across the fertilizer/pesticide–soil–fruit continuum in Padena, Semirom, combining paired soil and root-stem-fruit tissue analysis ( n = 36) with ecological and deterministic human health risk indices for adults and children. Results showed that mean soil concentrations were 22.5 ± 2.9 mg/kg for Pb and 2.12 ± 1.07 mg/kg for Cd, both above regional background levels, with the two elements almost perfectly correlated in soil (Spearman ρ = 0.996). Despite its ~ 10-fold lower concentration, Cd drove most ecological risk, reaching the very-high category in 83% of samples, while Pb stayed low. Pb showed low bioconcentration and near-unity translocation between tissues, consistent with restriction at the root; Cd was more root-mobile but sharply restricted from stem to fruit. Fruit Cd remained below its permissible limit, while mean fruit Pb, on a wet-weight basis, reached ~ 98% of the Iranian national limit. Hazard indices (0.06–0.08) and cancer risks (8.0–10.9 × 10⁻⁶) for both age groups stayed within or only marginally above internationally accepted thresholds. Pesticides accounted for 99.2% of the combined annual agrochemical load, yet a mass-balance check showed they could explain only 15.6–17.0% of soil Pb enrichment and 6.5–7.1% of Cd enrichment, pointing to additional, unquantified sources. Continued monitoring of fruit Pb is recommended.
Source: Discover Environment
Institution: Yazd University
Language: English
Topic: Heavy metals in environment
Subfield: Pollution
Field: Environmental Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,390
Funder: Yazd University
OpenAlex ID: W7224844872