Bioindicators: Study on Uptake and Accumulation of Heavy Metals in Plant Leaves of State Highway Road, Bagalkot, India

Abstract

In this study, Caesalpinia (Caesalpinia pulcherrima) and grass (Cyndon dactylon) was evaluated as the bioindicators of heavy metals such as the Lead (Pb), Copper (Cu), Cadmium (Cd), Manganese (Mn), Zinc (Zn), Chromium (Cr) and Nickel (Ni) contaminated in Bagalkot and along the state high way upto Mudhol. The soil samples at depth (0-20 cm) and caesalpinia and grass leaves were taken from different sampling stations namely Navnagar bypass road (S1), Gaddanakeri cross (S2), Tulasigeri (S3), Kaladagi (S4), Lokapur (S5), Chichakhandi (S6) and Mudhol (S7). The concentrations of Pb, Cu, Cd, Mn, Zn, Cr and Ni were measured using GBC- 932 plus Atomic Absorption Spectrophotometer (Austrelia). The results of  the  study  shows that the concentrations of heavy metals in caesalpinia ranged from Pb 20.36 to 29.39 µg/gmm, Cu 3.92 – 5.94 µg/gm, Zn 24.40 to 35.7 µg/gm, Cd 1.01 to 1.78 µg/gm, Mn 27.01 to 69.10 µg/gm, Cr 1.20 to 7.8 µg/gm and Ni 7.9 to 13.1 µg/gm. In grass heavy metal ranges between for Pb 20.16 to 28.01, Cu 3.95 to 5.76 µg/gm, Zn 24.50 to 35.8 µg/gm, Cd 1.15 to 1.52 µg/gm, Mn 28.91 to 72.51 µg/gm, Cr 1.28 to 8.0 µg/gm, Ni 8.1 to 15.1 µg/gm. Similarly in roadside soil heavy metal ranges between Pb 81.91 to 139.8 µg/gm, Cu 39.54 to 58.58 µg/gm, Zn 32.29 to 381.54 µg/gm, Cd 1.51 to 2.08 µg/gm, Mn 1257.9 to 2051 µg/gm, Cr 131.9 to 951.2 µg/gm and Ni 69.53 to 108.6 µg/gm. According to these results the concentration of heavy metals in grass was found high as compared to caesalpinia. Thus, compared to the metal accumulation potential grass is said to be heavy metal accumulator. The variation in heavy metal concentrations is due to changes in traffic density and anthropogenic activities. Thus, generally it is considered that grass and caesalpinia are good bioindicators and can be used in air pollution monitoring studies.