IOSR Journal Of Environmental Science, Toxicology And Food Technology (IOSR-JESTFT) e-ISSN: 2319-2402,p- ISSN: 2319-2399. Volume 8, Issue 1 Ver. III (Jan. 2014), PP 51-55 www.iosrjournals.org www.iosrjournals.org 51 | Page Air Pollution Tolerance Indices (APTI) of Six Ornamental Plants Commonly Marketed at “Ebano Tunnel” Floral Market, in Enugu Urban, Enugu State, Nigeria. *Otuu, Fred Chibuisi 1 , Inya-Agha Stella Ifeoma 2 , Ani, Uchenna Godwin 3 , Ude, C.M 4 , Inya-Agha, Tochukwu O 5 Drug Delivery/Environmental Research Unit, Dept. of Pharmaceutics, University of Nigeria Nsukka. Dept. of Pharmacognosy/Environmental Medicine, University of Nigeria Nsukka. Dept. of Estate Management, Enugu State University of Science and Technology, Enugu. Dept. of Applied Bio-Chemistry, Enugu State University of Science and Technology, Enugu. Dept. of Medical Laboratory Sciences, University of Nigeria Enugu Campus. Abstract:Enugu Urban Local Government Area is the capital of Enugu State in the South Eastern Geopolitical Zone of Nigeria. “Ebano Tunnel” is an important link road between the two busiest parts of Enugu Urban - the Ogui Urban area and the Abakiliki road/GRA. Owing to this strategic location, the “Ebeano Tunnel”, recently is witnessing massive floral market where ornamental plants are displayed. Six species of ornamental plants commonly marketed (Ficus, Hibiscus, Ixora, Phitis, Toja and Red rose) were evaluated for their Air pollution Tolerance Indices (APTI). The APTI of each plant was computed from four physiological and bio-chemical parameters namely: - P H of the leaf extract, Relative water content, Ascorbic acid and chlorophyll content. The APTI values ranged between 9.04-15.26 on Hibiscus and Toja respectively. The ornamental plants with high APTI (Tolerant) are recommended for use in domestic, industrial and urban land scapping both for their aesthetic values and phytoremediation potential of air polluted environment, while the plants with low APTI (Sensitive) are to be used as bio-indicators of environmental air quality. Keywords: Ornamental Plants, APTI, Land scapping, phytoremediation. I. Introduction Recently, there is a significant development in public and private infrastructural setup, vehicular activities and population increase in Enugu State in general and Enugu Urban in particular. The good governance of the present administration and the relative good security system in the Enugu State has attracted massive investment in real estate and manufacturing industries. This increases human and vehicular population with the resultant anthropogenic-induced environmental pollution of the domestic, industrial and urban air quality. In line with the growing real estate industry is the sharp rise in horticultural and floral activities. In the developing countries such as Nigeria, land-scapping and street-scapping are more for aesthetics than public health effect with the result that the property developers and individuals are more attracted to colours without regards to the ability of the plant to withstand stress-associated with environmental pollution of anthropogenic origin. Only recently have very few individuals and government agencies realized the significant public health benefits associated with ornamental plants and are therefore, beginning to select them on the basis of beauty and longevity. Air Pollution Tolerance Index (APTI) in plants is the evaluation of the susceptibility level of plants to air pollution (pollutants), using four parameters, namely ascorbic acid content, chlorophyll, relative water content, and pH value of leaf extract, (Agarwalet al., 1991). Plants with high index values are more tolerant to air pollutants. Ordinarily, tolerance of plants to air pollution can be measured by simple symptoms such as visible injury on the plants, but it can be correctly evaluated by calculating the tolerance index of plants to air pollutants. Plants are classified into three categories of sensitivity: APTI < 10, sensitive, APTI 10- 16, intermediate, APTI ≥ 16 tolerant, (Agarwal and Singh, 1991). This study evaluated the Air Pollution Tolerance Indices of six Ornamental plants marketed at the floral garden along “EbanoTunel”, off Abakiliki road G.R.A Enugu. Recently there is a high degree of awareness on the significance of plants in screening UV lights and particulate dust from having direct access to human health, so that the use of ornamental plants by land scappers and architects in residential buildings, industrial sites and public parks has gone beyond beautification to include health protection. The ability of plants to serve these purposes is influenced by their air pollution tolerance indices, (Kousaret al., 1999). This study was predicated on the above. Sensitive species are more useful as bio- indicators and tolerant species are more appropriate as phyto-remediating agents in polluted environments. The bio-indicators assist in planning the urban cities to avoid pollution (Ghosh, 1992).