Evaluation of genotoxicity of coal fly ash in Allium cepa root cells by combining comet assay with the Allium test

  • Rajarshi Chakraborty
  • Ashit Kumar Mukherjee
  • Anita MukherjeeEmail author


Fly ash is a by-product of coal-fired electricity generation plants. Its utilization and disposal is of utmost importance. Using onion (Allium cepa) root tip system, the present study was carried out to evaluate the potential toxic and genotoxic effects of fly ash, collected from a thermal power plant in West Bengal, India. Prior to testing, the collected fly ash sample was mixed with sand in different proportions. Allium bulbs were allowed to germinate directly in fly ash and after five days the germinating roots were processed for the Allium test. Additionally, the Allium test was adapted for detecting DNA damage through comet assay. The results from the Allium test indicate that fly ash at 100% concentration inhibits root growth and mitotic indices; induces binucleated cells as a function of the proportion, but is not toxic at very low concentration. In the comet assay, a statistical increase for DNA strand breaks was found only at higher concentrations. The sample was analyzed by flame atomic absorption spectrometer for Zn, Pb, Cu, Ni, Cd and As, whose presence could partly be responsible for the toxicity of fly ash. The study concludes that the classical Allium test can give a more comprehensive data when done in combination with the comet assay, which is faster, simpler and independent of mitosis. Also when fly ash is used for other purposes in combination with soils, it should be judiciously used at very low concentrations in order to protect the ecosystem health from any potential adverse effects.


Binucleated cell Cytotoxicity DNA damage Heavy metals Single Cell Gel Electrophoresis 


  1. Antonsie-wiez, D. (1990). Analysis of the cell cycle in the root meristem of Allium cepa under the influence of Leda krin. Folia Histochemica et Cytobiologia, 26, 79–96.Google Scholar
  2. Dovgalik, A. I., Kaliniiak, T. B., & Blium, B. (2001). Cytogenetic effects of toxic metal salts on apical meristem cells of Allium cepa L. seed roots. Tsitologiia i Genetika, 35, 3–10.Google Scholar
  3. el-Mogazi, D., Lisk, D. J., & Weinstein, L. H. (1988). A review of physical, chemical, and biological properties of fly ash and effects on agricultural ecosystems. The Science of the Total Environment, 74, 1–37.CrossRefGoogle Scholar
  4. Fairbairn, D. W., Olive, P. L., & O’Neill, K. L. (1995). The comet assay: a comprehensive review. Mutation Research, 339, 37–59.Google Scholar
  5. Fiskesjö, G. (1988). The Allium test- an alternative in environmental studies: the relative toxicity of metal ions. Mutation Research, 197, 243–260.Google Scholar
  6. Gichner, T., Mukherjee, A., & Velemínský, J. (2006). DNA staining with the fluorochromes EtBr, DAPI, YOYO-1 in the comet assay with tobacco plants after treatment with ethyl methanesulphonate, hyperthermia and DNase-1. Mutation Research, 605, 17–21.Google Scholar
  7. Gichner, T., & Plewa, M. J. (1998). Induction of somatic DNA damage as measured by single cell gel electrophoresis and point mutation in leaves of tobacco plants. Mutation Research, 401, 143–152.Google Scholar
  8. Gonzalez-Fernandez, A., & Lopez-Saez, J. F. (1985). Effect of caffeine and adenosine on G2 repair, mitotic delay and chromosome damage. Mutation Research, 149, 275–281.Google Scholar
  9. Gopalan, H. N. B. (1999). Ecosystem health and human wellbeing: the mission of the International Program on Plant Bioassays. Mutation Research, 426, 99–102.Google Scholar
  10. Hartwig, A. (1995). Current aspects in metal genotoxicity. Biometals, 8, 3–11.CrossRefGoogle Scholar
  11. Kalra, N., Jain, M. C., Joshi, H. C., Chaudhary, R., Kumar, S., Pathak, H., Sharma, S. K., Kumar, V., Kumar, R., Harit, R. C., Khan, S. A., & Hussain, M. Z. (2003). Soil properties and crop productivity as influenced by fly ash incorporation in soil. Environment Monitoring and Assessment, 87, 93–109.CrossRefGoogle Scholar
  12. Kong, M. S., & Ma, T. H. (1999). Genotoxicity of contaminated soil and shallow well water detected by plant bioassays. Mutation Research, 426, 221–228.Google Scholar
  13. Ma, T. H. (1999). The International Program on Plant Bioassays Collaborative Studies with Plant Systems. Mutation Research, 426, 97–98.Google Scholar
  14. Mukherjee, A., & Sharma, A. (1987). Effects of cadmium and zinc on cell division and chromosomal aberrations in Allium sativum. Current Science, 56, 1097–1100.Google Scholar
  15. Mukherjee, A., & Sharma, A. (1988). Effects of cadmium and selenium on cell division and chromosomal aberrations in Allium sativum. Water Air and Soil Pollution, 37, 433–438.CrossRefGoogle Scholar
  16. Navarrete, M. H., Carrera, P., Miguel,, & de la Torre, C. (1997). A fast comet assay variant for solid tissue cells. The assessment of DNA damage in higher plants. Mutation Research, 369, 271–277.Google Scholar
  17. Ostling, O., & Johanson, K. J. (1984). Microelectrophoretic study of radiation—induced DNA damages in individual mammalian cells. Biochemistry Biophysics Research Communication, 123, 291–298.CrossRefGoogle Scholar
  18. Panda, K. K., Lenka, M., & Panda, B. B. (1990). Monitoring and assessment of mercury pollution in the vicinity of a chloralkali plant. 1. Distribution, availability and genotoxicity of sediment mercury in the Rushikulya estuary, India. The Science of the Total Environment, 96, 281–296.CrossRefGoogle Scholar
  19. Panda, B. B., & Sahu, U. K. (1985). Induction of abnormal spindle function and cytokinesis inhibition in mitotic cells of Allium cepa by the organophosphorus insecticide fensulfothion. Cytobios, 42, 147–155.Google Scholar
  20. Sharma, A. K., & Sharma, A. (1980). Chromosome Techniques-Theory and practice, 3rd ed. London: Butterworth.Google Scholar
  21. TERI (Tata Energy Research Institute) (2000). Reclaiming ash ponds and immobilizing heavy metals by means of mycorrhizal organo-biofertilizer at Korba STPS, Annual Report. New Delhi: TERI.Google Scholar
  22. Watanabe, T., & Hirayama, T. (2001). Genotoxicity of soil. Journal of Health Science, 47, 433–438.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2008

Authors and Affiliations

  • Rajarshi Chakraborty
    • 1
  • Ashit Kumar Mukherjee
    • 2
  • Anita Mukherjee
    • 1
    Email author
  1. 1.Centre of Advanced Study in Cell and Chromosome Research, Department of BotanyUniversity of CalcuttaKolkataIndia
  2. 2.Regional Occupational Health Centre (E) Block-DPKolkataIndia

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