The study of the effects of low-level exposure to ionizing radiation using a bio-indicator system

The object of the present study was to apply the high sensitivity of a botanical mutagenicity test (Tradescantia stamen-hair mutation bioassay), in “in situ” bioassays to determine the responses induced by the exposure to low levels of ionizing radiation. Mutagenesis was evaluated during 28 days, in an environment that presented gamma radiation exposure rates of 1.6 (control), 25.0 and 75.0 μR min−1. From the results we observed that there was no linear response throughout the exposure time when compared mutagenic events and gamma radiation exposure rates were compared. The results obtained in the second week of exposure of Tradescantia showed that after exposure to 25.0 and 75.0 μR min−1 there was a significant increase (p<0.05) in the mutation levels in Tradescantia stamen-hair. In the third and fourth week after exposure 25.0 μR min−1, the plants demonstrated a mutation rate that was not significantly different from the control (p>0.05).