Nasirpour et al. 2026 — Heavy metals in apple fruit, leaves, and soil under treated wastewater irrigation, Iran
This study measured the accumulation of heavy metals and essential elements in apple (Cultivar: Golden Delicious) fruit, leaves, and soil under irrigation with urban treated wastewater compared to clean water controls over a 2021-2023 field experiment in Iran (BMC Plant Biology 2026:26:441). Metals measured in fruit included As, Se, Ba, and Sr; in leaves: As, Co, Cr, Ni, Pb, Se, and Ba; in soil: As, Co, Cr, Ni, Pb, and Ba. The study found that irrigating apple trees with treated wastewater led to measurable accumulation of heavy metals in soil and plant tissues, including in the edible fruit, compared to conventionally irrigated controls. This has direct implications for food safety in regions where wastewater irrigation of fruit orchards is practiced.
Key numbers
Experiment duration: 2021-2023 (3 years). Apple cultivar: Golden Delicious. Irrigation treatments: urban treated wastewater vs. clean water control. Metals detected in apple fruit: As, Se, Ba, Sr (values reported in source tables). Metals elevated in leaves under wastewater irrigation: As, Co, Cr, Ni, Pb, Se, Ba. Soil accumulation detected for As, Co, Cr, Ni, Pb, Ba. Specific ppb values are reported in the source tables.
Methods (brief)
Field experiment in Iran with Apple Golden Delicious cultivar. Irrigation treatments: urban treated wastewater versus clean groundwater controls. Multi-element analysis of fruit pulp, leaves, and rhizosphere soil. Analytical method: ICP-based elemental analysis (specific instrument not specified in abstract). Duration: 3 growing seasons (2021-2023).
Implications
Certification: Treated wastewater irrigation is a growing practice in water-scarce regions; confirms metal transfer pathway from irrigation water to apple fruit for As, Cr, Ni, Pb. Courses: Illustrates agricultural water quality as a source of heavy metal contamination in fruit crops. App: Apple risk profile should note irrigation water quality as a key driver, particularly in water-scarce Middle Eastern and Central Asian production regions.