Abstract:
Contamination of soil with used lubricant oil is an emerging environmental
problem in most of the cities across the world. Accidental spills, illegal
dumping and careless handling of used lubricant oil have been significant
sources of environmental pollution. Allium cepa test system is a simple
sensitive and rapid bioassay widely used as a standard method for the
biomonitoring of environmental contaminants. The present study was
carried out to assess the applicability of Allium cepa test system in the
toxicity characterization of used lubricant oil contaminated soils. Inhibitions
in root growth and number of roots of Allium bulbs exposed to a range of
used lubricant oil contaminated soils were recorded as phytotoxicity end
points. Further, the calculated mitotic indexes and the observed different
types of chromosomal aberrations in the root meristematic cells were
considered as genetic end points. Chromosomal aberrations were detected
by staining the root meristematic cells with toluidene blue. The tested soils
exerted toxicity for all the evaluated end points with the dose dependent
manner. Chromosomal aberrations were observed in all the phases of
mitosis of root meristematic cells of Allium cepa. Chromosomal bridges
were most prominent in the anaphase and the telophase of the cell cycle and
abnormal chromosomal arrangements and nuclear buds were also observed.
Thus the results highlighted the applicability of Allium cepa test system not
only for phytotoxicity characterization but also for the characterization of
potential cytotoxicity and genotoxicity of the used lubricant contaminated
soil.
