Pollution Levels of Lead and Copper in the Areas Surrounding Diyala State Company, Iraq

Pollution by toxic metals represents a great environmental concern. Industrial activities release high levels of metals into the environment, adversely affecting human health. This study aimed to assess levels of lead and copper contamination in the areas surrounding Diyala State Company as well as to evaluate the efficiency of roadside plants in absorbing these metals from soil by their leaves, thereby exploring their role in reducing environmental pollution. Soil and leaf samples were collected from four directions surrounding the company and at distances in each direction (100, 500, 1,000, 2,000 meters). Leaf samples were collected from four plants: Eucalyptus camaldulensis, Ricinus communis, Dodonaea viscosa, and Malva parviflora between June and August 2024. The findings revealed high concentrations of lead and copper. The highest lead concentration was in the eastern part (3 mg/kg) in E. camaldulensis at site E3. The highest copper concentration was in the northern part (1.36 mg/kg) in R. communis at site N2, and D. viscosa was recorded with the highest lead concentration (2.43 mg/kg) in the northern part at site N4. M. parviflora showed higher lead concentration in the western part (1.58 mg/kg) at site W1. The maximum bioaccumulation coefficient for lead uptake was exhibited in E. camaldulensis, followed by R. communis, which also demonstrated the highest uptake of copper in most locations, particularly in the northern part. According to their efficiency in heavy metal uptake and accumulation, the plants were ranked as follows: E. camaldulensis > R. communis > D. viscosa > M. parviflora. It is clear that these plants have shown a high capacity for absorbing heavy metals, which positively impacts the environment and allows for their inclusion in bioremediation programs.