Document Type



With a view to assess the possible long-term effects of chronic low-level radiation on human quantitative characters, several dermatoglyphic param­eters were studied among the inhabitants of monazite belt in Kerala, India. Previous investigators have estimated that these populations are exposed to 87r per 30 years. Dermatoglyphic data from 74 males native to this area were compared with those from 72 ethnically comparable males native to another area exposed to near-normal levels (6r per 30 years) of background radiation. All the six quantitative characters so studied showed lower variance among the exposed population as compared to the “controls”. Two possible interpretations have been considered to account for this somewhat puzzling finding: (1) The exposed population may have originated from a small group of possibly related individuals; then subsequent expansion of the population may have occurred in the absence of significant additional immigration. (2) The effects of chronic low level radiation may not be the same as those of high acute doses; the former may sometimes decrease rather than increase variance of quantitative traits.