In a recent paper (Ushov, PRL, 80, 230, 1998), it has been claimed that the bare surface of a strange star can emit electron-positron pairs of luminosity ~10^{51} ergs/s for about 10s. If true, obviously, this mechanism may explain the origin of cosmic Gamma Ray Bursts. However, we point out that such a mechanism is does not work because (i) if pair production really occurs the supposed pre-existing supercritical electric field will be quenched and this discharge process may at best release ~10^{24} ergs of electromagnetic energy, and (ii) there is no way by which the trapped core thermal energy of few 10^{52} ergs can be transmitted electromagnetically on a time scale of ~10s or even on a much larger time scale. The only way the hot core can cool on a time scale of ~10 s or much shorter is by the well known process of emission of nu-antinu pairs.
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