Air Pollution Tolerance Index and Biochemical constituents of some plants growing in Neyveli Lignite Corporation (NLC), Tamil Nadu, India

Plant species can be effectively used as filters to reduce air pollution and also as bio-indicators of urban air quality. Screening of plants for their sensitivity/tolerance level to air pollutants is important because the sensitive plants can serve as bio-indicator and the tolerant plants as sink for controlling air pollution in urban and industrial areas. Biochemical parameters namely Relative Water Content, leaf extract pH, ascorbic acid, chlorophyll, starch, protein, amino acid, reducing and total sugar were estimated to generate Air Pollution Tolerance Index (APTI) for ten plants each at polluted site and control site. The results showed that Terminalia catappa (18.16 and 16.19) and Mangifera indica (16.01 and 15.98) have recorded high and low values in both the sites respectively. In comparison between the two sites, all the values were slightly higher in the polluted site than the control for all the ten plants and a considerable variation was observed among the four parameters where their percentage variations were considered. Terminalia catappa, Mangifera indica and Calotropis gigantea were found to be tolerant towards air pollution