The past decades have been characterized by an intense urbanization. The effect of plant cover on diffusion of pollutants has increased the effort to reduce the concentration of air pollutants by plants in the urban environment. Due to the extensive use of plantain ( Platanus orientalis L.) in the urban green space of Isfahan, this tree was considered for this research. This study was conducted as split plot based on randomized complete block design with 8 replications. The main factor was time and factor of leaf washing treatment and this research was carried out in natural conditions of Isfahan in public green space on mature adult trees. BecameThis purpose, eight standard planted trees were selected and coded at Chaharbagh Abbasi Street in Isfahan. Two times a month, half of the trees encoded with water were washed and three times the leaves were washed and washed each half. The trees were prepared and transferred to the greenhouse of the Faculty of Agriculture of Isfahan University of Technology in order to measure some of the physiological characteristics, antioxidant enzymes, soluble carbohydrates and malondialdehyde. Measurement of temperature and humidity (the most important climatic comfort indices) was measured monthly and the concentration of suspended particles (in three periods). The results are as follows: Temperature of areas with green space was significantly lower and the moisture content of green areas was significantly higher than that of control areas. Concentration of suspended particles (PM 10 ) in areas with green space was significantly lower than that of control areas. significant differences were observed in the amount of chlorophyll a, total chlorophyll and the enzyme guaiac peroxidase in all three time indices, leaf type (washed and unwashed leaves), and the interaction between the leaf type and the time between the washed and washed leaves. The amount of chlorophyll b, cartonoid and catalase enzyme due to time and interaction of time and leaf type showed a significant difference between the washed and unplaced leaves. The amount of soluble carbohydrates (sugar) increased significantly in washed leaves due to time (October). Malondialdehyde in unwashed leaves had a significant increase compared to the washed leaves. Key words : Suspended Particles, Plantain, Physiological Properties, Climatic Comfort
