Chromosomal Aberrations As an Evidence of Genetic Damage in the Offspring of Methyl Isocyante Exposed Population of Bhopal

Ravi Sukumaran¹, Tahir Mohiuddin Malla², Rekha Khandia³, N. Ganesh^1*
1Department of Research, Jawaharlal Nehru Cancer Hospital & Research Centre, Idgah Hills, Bhopal M.P
²Cancer Diagnostic and Research Centre, Sher-i-Kashmir Institute of Medical Sciences, Srinagar (J&K)
³Department of Biochemistry & Genetics, Barkatullah University, Bhopal (M.P.)

A B S T R A C T
Introduction: Bhopal gas tragedy was one of the worst industrial disasters that produced various short-term as well as ling-term health effects in the exposed population. Various studies have revealed the long-term genotoxicity of the exposure in the human population. However, the genotoxicity in the offspring of the exposed individuals remains unexplored. The present study is an attempt to study the genomic damage caused by MIC in the offspring of the exposed population and to know about the pattern and frequency of chromosomal aberrations in them.  Material and Methods:  Fifty healthy offspring of the MIC exposed individuals living in the vicinity of 1.5 km from the Union Carbide’s pesticide plant were selected at random as the study subjects. Equal number of age, sex and locality matched non-exposed individuals were also enrolled as controls. All the subjects were non smokers and not employed at any type of chemical industry or a radiation department. Cytogenetic analysis was performed by standard protocol of lymphocyte culture as per Moorhead et al. Hundred metaphase spreads per sample were observed and the chromosome aberrations were classified according to the International Nomenclature. Student’s t test was performed to test the significance of difference between means of chromosomal aberrations recorded. The means were considered to be statistically significant at 1% level of probability. Results:  Chromosomal aberrations were recorded at mitotic metaphases. Mean percentage of total abnormal metaphases (TAM) in the offspring group was observed to be 54.7±0.81 which was statistically higher (4.6±0.16) than that of non-exposed controls (P<0.01). The offspring group revealed statistically elevated chromosome-type (13.9±0.17) and chromatid-type aberrations (14.26±0.2) as compared to the non-exposed group (0.4±0.54 and 0) respectively. Besides, acrocentric associations were found to be higher (13.7±4.89) in the offspring group than the controls (0.6±0.70).
Keywords: Chromosomal aberrations, Methyl isocyanate, Bhopal gas tragedy, long-term genotoxicity