Frequency of chromosome aberrations among adult male individuals from high and normal level natural radiation areas of Kerala in the southwest coast of India

Chromosome aberration analysis was carried out in peripheral blood lymphocytes of adult male individuals from normal level natural radiation areas (NLNRA, ≤1.5 mGy/year, N = 27) and high level natural radiation areas (HLNRA, >1.5mGy/year, N = 70) of Kerala coast in southwest India. The mean age of individuals from NLNRA and HLNRA was 40.9 ± 9.4 and 43.7 ± 12.4 years, respectively, with an overall mean of 42.9 ± 11.6 (range: 18-80). Whole-blood cultures were set up and about 260 metaphases were scored per individual. The frequency of chromosome aberrations was calculated per 1000 cells. The overall basal frequency of unstable (dicentrics and rings), stable (translocations and inversions) and other (fragments and breaks) aberrations was 1.54 ± 0.25, 4.1 ± 0.40 and 6.66 ± 0.51, respectively. Individuals of NLNRA and HLNRA had statistically similar frequency of unstable (2.11 ± 0.64 v/s 1.39 ± 0.26; RR = 0.66; 95% CI: 0.33-1.33), stable (4.60 ± 0.94 v/s 3.97 ± 0.44; RR = 0.86; 95% CI: 0.55-1.36) and other (7.85 ± 1.23 v/s 6.36 ± 0.56; RR = 0.81; 95% CI: 0.57-1.15) chromosome aberrations. Frequencies of unstable, stable and other chromosome aberrations did not show any dose response after stratification of HLNRA samples into three dose groups (1.51-5.0 mGy/year, 5.01-10 mGy/year and >10.0 mGy/year). Smokers showed an increase in other chromosome aberrations (P < 0.001), but smoking was not associated with unstable and stable aberrations. Alcohol consumption and tobacco chewing had no significant association with any type of chromosome aberrations. In conclusion, chronic low dose radiation prevailing in Kerala coast did not show any significant effect on the basal frequency of chromosome aberrations among the adult population.