Environmental Risk Assessment of Heavy Metals in Dust and Their Impact on Roadside Plants Due to Traffic Activity in Diyala Governorate, Iraq.

ABSTRACT: The current study aims to evaluate the levels of dust pollution on plants grown on roadsides and resulting from traffic in Diyala Governorate. Four locations were chosen that represent different levels of traffic density and industrial activity: Al-Tabu Street, Khuraisan Street, Buhriz Street, and Hay Al-Muallem Street. Concentrations of heavy metals were measured, including lead [Pb], cadmium [Cd], copper [Cu], and zinc [Zn], and the results showed The highest concentration of heavy metals was recorded in zinc, which reached 145.9 mg/kg and lead, 61.2 mg/kg. This is attributed to Due to the high traffic density and industrial activities, the lowest concentrations were in Buhriz Street, where the lowest concentration of cadmium was 1.2 mg/kg, while the copper concentration reached 22.1 mg/kg due to the lack of traffic activity. The current study also included measuring the physiological functions of plants, including [ Photosynthesis rate, stomatal measurement, and chlorophyll concentrations], as the results showed that dust accumulation has effects on the physiological functions of plants, through a decrease in construction efficiency. Photosynthesis and differences in chlorophyll concentrations. The study also showed the impact of traffic and industrial activities on plant life as a result of dust falling on the surfaces of their leaves, which emphasizes the importance of working to reduce dust pollution levels in urban areas to improve environmental quality.