The Genotoxicity of Priority Polycyclic Aromatic Hydrocarbons (PAHs) Containing Sludge Samples

Area of Science:

• Environmental Toxicology
• Mammalian Cell Culture
• Genotoxicity Assays

Background:

• Oily sludges from petroleum industries pose risks due to toxic chemicals like polycyclic aromatic hydrocarbons (PAHs).
• Assessing the genotoxic potential of complex environmental mixtures like oily sludges is challenging due to limited data and understanding of synergistic effects.

Purpose of the Study:

• To evaluate the genotoxic potential of oily sludges from Indian petroleum industries using mammalian cell cultures.
• To assess the risk posed by these sludges to human health.

Main Methods:

• Utilized Chinese Hamster Ovary (CHO-K1) cell cultures for in vitro genotoxicity testing.
• Employed a battery of assays including DNA damage/strand break, chromosomal aberration, p53 protein induction, and apoptosis.
• Analyzed sludge extracts using Gas Chromatography-Mass Spectrometry (GC-MS) to identify polycyclic aromatic hydrocarbons (PAHs).

Main Results:

• Exposure to oily sludge extracts at various doses (25, 50, 100 μL) induced significant DNA damage, chromosomal aberrations, p53 protein induction, and apoptosis in CHO-K1 cells (P < 0.001).
• Genotoxicity was confirmed and attributed to the presence of PAHs identified in the sludge samples.
• The results demonstrate a clear genotoxic effect of oily sludges on the tested mammalian cell system.

Conclusions:

• Oily sludges from the studied petroleum refineries are genotoxic to mammalian cells.
• Exposure to these genotoxic sludges may present a significant risk to human health.
• In vitro mammalian cell culture systems provide a rapid method for assessing the health risks of environmental contaminants.