International Journal of Environmental Monitoring and Analysis 2015; 3(1): 22-27 Published online January 30, 2015 (http://www.sciencepublishinggroup.com/j/ijema) doi: 10.11648/j.ijema.20150301.14 ISSN: 2328-7659 (Print); ISSN: 2328-7667 (Online) Evaluation of air pollution tolerance indices of four ornamental plants arranged along roadsides in Abidjan (Côte d'Ivoire) Zamblé Fidèle Tra Bi 1 , Djédoux Maxime Angaman 2, * , Yao Sadaiou Sabas Barima 3 , Bini Kouamé Dongui 3 1 UFR Sciences et Gestion de l'Environnement, Université Nangui Abrogoua, Abidjan, Côte d'Ivoire 2 UFR Agroforesterie, Université Jean Lorougnon Guédé, Daloa, Côte d'Ivoire 3 UFR Environnement, Université Jean Lorougnon Guédé, Daloa, Côte d'Ivoire Email address: angamanmaxime@yahoo.fr (D. M. Angaman) To cite this article: Zamblé Fidèle Tra Bi, Djédoux Maxime Angaman, Yao Sadaiou Sabas Barima, Bini Kouamé Dongui. Evaluation of Air Pollution Tolerance Indices of Four Ornamental Plants Arranged Along Roadsides in Abidjan (Côte d'Ivoire). International Journal of Environmental Monitoring and Analysis. Vol. 3, No. 1, 2015, pp. 22-27. doi: 10.11648/j.ijema.20150301.14 Abstract: The development of urbanization and industrialization contributes to ambient air pollution of the city of Abidjan. Air pollution can affect plants morphology and physiology. Plants can absorb gaseous and particulates pollutants through leaves, they tend to show some symptoms according to their level of sensitivity after exposure to the air pollution. In order to evaluate the susceptibility level of plants to air pollutants, four biochemical and physiological parameters, namely; ascorbic acid, chlorophyll, relative water content and leaf extract pH were determined and computed together in a formulation of air pollution tolerance indices (APTI) of Ficus benjamina, Jatropha integerrima, Cassia surattensis and Barleria prionitis arranged along main roads (MR) as well as in parks (P) as control in Abidjan. APTI values for overall species are ranged between 9.78 to 17.15 in P and from 9.76 to 16.91 in MR. The highest APTI is observed in Ficus benjamina and lowest in Cassia surattensis. Ficus benjamina was categorized as intermediate tolerant specie; and Jatropha integerrima, Barleria prionitis were categorized as intermediate sensitive species contrary to Cassia surattensis which was sensitive specie. Thus, tropical urban air quality evaluation is possible by using plants APTI. Keywords: Air Pollution, Air Pollution Tolerance Index, Main Roads, Côte d'Ivoire 1. Introduction The rapid urbanization and growing industrialization in the world during the last decades led to increasing levels of air pollution [1] dwindling urban air quality [2] . Plants play an important role in monitoring and maintaining the ecological balance by their involvement in the cycling of nutrients and gases like carbon dioxide and oxygen [3]. However, air pollutants like gases and particulate matters cause environmental stress in plants which can change their leaf structure and physiology [4,5,6]. Air pollutants can alter the leaf epidermis [7] and affect stomatal conductance [8]. The physiological and biochemical responses of plants to air pollution can be understood by analyzing the factors determining resistance and susceptibility [9]. Plants sensitivity and tolerance to air pollutants varie with change in leaf extract pH, relative water content, ascorbic acid content and total chlorophyll content [10]. Ascorbate was known as an antioxidant molecule able to detoxify air pollutants [11] and it is also able to control cell expansion and cell division [12,13]. Chlorophyll is essential for the vital process of photosynthesis in green plants. Changes in leaf chlorophyll can serve as relative indicators of environmental quality [14]. The importance of pH in mediating physiological responses to stress was another reason in including it in air pollution tolerance index component [15]. Single parameter may not provide a clear explanation of the pollution-inducted changes, [16] used these four parameters for identifying tolerance levels of plant species