Seasonal Variation and Health Risk Assessment of Cd, Pb, and Nitrate in Vegetables and Fruits Available in North West of Iran

Introduction: Given the significant role of fruits and vegetables in the Iranian diet, this study aimed to evaluate the health risks linked to the heavy metals in 6+ fruits and vegetables, specifically cadmium (Cd) and lead (Pb), as well as nitrate in household diets. Materials and Methods: A total of 1941 fresh samples were collected from East and West Azerbaijan province in Iran across three seasons. Then, the concentration of Cd, Pb, and nitrate were examined. Results: Analysis using SPSS software version 20 found that all vegetable samples contained heavy metals and nitrates, with Cd levels within permissible limits. Pb concentrations varied by season: 40.4-280.33 ppb in spring, 36.77-283.67 ppb in summer, and 6.21-236.23 ppb in autumn. Pb levels exceeded the national standard organization of Iran (INSO) limit in several samples, including greenhouse cucumbers (48.48%) and conventional cucumbers (62.22%), onions (48.71%). Nitrate concentrations included 45.33-3390 ppb in spring, 9.66-3581 ppb in summer, and 34.28-3281.94 ppb in autumn, with exceedances in samples such as spinach (92%) and leafy vegetables (100%). Despite these exceedances, the target hazard quotient (THQ) for Cd, Pb, and nitrates was below 1, indicating no immediate health risks for the Iranian population. Conclusion: While the presence of Pb and nitrates in certain vegetable samples raises concerns regarding food safety and compliance with health standards, the overall assessment suggests that the levels of these contaminants do not currently pose a significant health risk. Continuous monitoring and adherence to safety standards are essential to ensure public health safety.