Jatinder Kaur Katnoria*, Rajneet Kour Soodan, Dipakshi Sharma & Avinash Nagpal
Department of Botanical and Environmental Sciences, Guru Nanak Dev University, Amritsar-143005, Punjab (INDIA)
Received 25th December, 2009; Revised 21st February, 2010
Abstract : Diverse genotoxins are being released into air from various anthropogenic sources such as industrial power plants, municipal incinerators and motor vehicles. The exposure to these air pollutants particularly from motor vehicles emissions, which ultimately descend to the nearby ground surfaces, represents an important cause of concern for their possible long-term effects on human health. Considering this, the present study was planned to estimate the heavy metal content and genotoxic potential of roadside soils of Amritsar, Punjab (India) employing chromosomal aberration assay in Allium cepa. The samples were collected from six different junction points of roadsides of Amritsar viz., Chhehrta junction, Guru Nanak Dev University junction, Putlighar junction, Railway station junction, Crystal junction and Bus stand junction. For estimation of genotoxic potential, the extracts of soil samples were prepared by suspending soil in distilled water in ratio of 1 : 2 (w/v) for 12 h. Different concentrations of extracts (10%, 25%, 50%, 75% and 100%) were used for treatment of onion roots for three hours. The root tips were squashed in aceto-orcein and slides were screened for different chromosomal aberrations. All the samples were found to be significantly genotoxic. The genotoxic potential of the soil samples was correlated with content of heavy metals like cobalt, copper, manganese, nickel and zinc, which were estimated using Atomic Absorption Spectrophotometer. Though no direct correlation was observed between genotoxic potential and heavy metal content of the soils, yet, the samples which showed higher genotoxicity also had higher contents of one or the other heavy metal studied. The present study illustrates the increasing vehicular pollution in Amritsar city and reveals that Allium cepa root chromosomal assay can be a first alert indication of soil contamination due to vehicular pollution.