Effects of stable strontium ions and a low-frequency pulsed magnetic field on the frequency micronuclei in the tadpoles erythrocytes of anuran amphibian

Living organisms are constantly exposed to the simultaneous action of many factors of chemical and physical nature. We studied the mutagenic effects of exposure to various concentrations of stable strontium ions and a low-frequency pulsed magnetic field during their independent and simultaneous effects on tadpoles of the toad Bufo viridis . In the first series of experiments, different groups of tadpoles were placed for 6, 12, 18, and 24 hours in aquariums with water containing strontium chloride with the metal ion concentrations of 14, 35, 70, 175, 350, 525, and 700 mg/L. In the second series of experiments, the tadpoles were in water with the same concentrations of strontium for 24 hours, and for the first 8 hours of this period they were exposed to a low-frequency pulsed magnetic field (41 mT, 16 Hz). After the end of exposure, blood smears of tadpoles were prepared and the frequencies of micronuclei and nuclear anomalies in erythrocytes were analyzed. It was found that with the duration of exposure to strontium ions equal to 6 and 12 hours, none of the studied concentrations of strontium caused a statistically significant increase in the total frequencies of micronuclei and nuclear anomalies. The frequency of micronuclei and nuclear anomalies in tadpole erythrocytes increased statistically significantly after 18 h exposure and strontium concentration over 175 mg/L. With a 24-hour exposure to metal ions, the minimum mutagenic concentration of strontium was 70 mg/L. Simultaneous action of strontium ions and a low-frequency pulsed magnetic field (41 mT, 16 Hz) led either to a simple summation or to a weakly manifested antagonism of the mutagenic effects of the two factors. However, at the maximum studied metal concentration (700 mg/L), a weak synergistic effect of strontium mutagenicity and a low-frequency pulsed magnetic field was established.