The dielectric properties in the frequency range from 100 Hz to 100 kHz of polyallyldiglycol carbonate ''CR-39'' samples before and after irradiations have been investigated. The irradiations were verified with 4.84 MeV a-particles at different irradiation times. The dependence of the dielectric properties of unirradiated and irradiated samples at room temperature (25 C) and constant frequency (10 kHz) on the total number of a-particles have been studied. It was found that the CR-39 can be used as a detector for high a-particles fluxes.