Car Traffic Pollution and its Impact on the Anatomical Characteristics of Carissa Macrocarpa (Eckl.) A. DC. Leaves in the City of Hit

An experiment was conducted to study the effect of pollution caused by vehicle emissions due to increased traffic on the leaves of C. macrocarpa on the main street in Hit. on the main street of Hit, located approximately 70 km. west of Ramadi, the center of Al Anbar Governorate, Where the traffic is highly concentrated due to the presence of markets and medical clinics. Three locations were selected based on varying levels of traffic congestion along the main street (Alchery): Site 1 had low congestion, Site 2 had moderate congestion, and Site 3 had high congestion. A control sample was stored away from pollution sources. This pollution measure in the plant indicates the effects of pollutants on living organisms. Various anatomical changes in the leaves were studied. The study lasted 40 hours over 10 days, with 4 hours daily observation. The results showed that plants in the most congested areas were the most affected by a significant increase in the reduction of all studied anatomical traits, such as stomatal diameter, guard cell size, epidermal cells, and stomatal number. The greatest decrease was observed at Site 3, with the decrease lessening as traffic congestion reduced in Sites 2 and 1, respectively, compared to the control sample. These results were consistent for both the upper and lower surfaces of the leaves.