Determination of some heavy metals concentrations in green and yellow wheat crops from Iraqi fields: a comparative analysis of heavy metal accumulation

Abstract

Wheat is a crucial staple crop in Iraq, essential for food security. However, heavy metal contamination from sources like irrigation water and fertilizers can pose risks to both plant health and human consumption. This study compares heavy metal levels in green and yellow wheat plants, in five agricultural regions in Iraq: Baghdad, Kirkuk, Salah Al-Din, Al Anbar, and Basra, addressing a gap in research specific to Iraqi wheat and its safety. The research analyzed six heavy metals—iron (Fe), manganese (Mn), copper (Cu), zinc (Zn), cadmium (Cd), and lead (Pb)—in different plant parts using atomic absorption spectrophotometry (AAS). Green plants generally had higher levels of essential metals, while yellow plants, indicative of iron deficiency, accumulated more toxic metals like Cd and Pb. Notably, all cereal samples (the edible part) exceeded the FAO/WHO cadmium limit of 0.02 mg/kg, and some exceeded the lead limit of 0.03 mg/kg, suggesting potential health risks, especially for children. Despite no acute risk, the study emphasizes the need for long-term monitoring to manage contamination. Green wheat is recommended for food due to its lower toxic metal content, while yellow wheat could be used for phytoremediation to clean up contaminated soils. This aligns with the United Nations’ Sustainable Development Goals (SDGs) 2 (Zero Hunger) and 3 (Good Health), providing data for agricultural and health policies.