We present optical to radio spectral energy distribution fitting of the host galaxies of four long gamma-ray bursts : 980703 , 000210 , 000418 and 010222 , which were detected at submillimetre and/or radio wavelengths .
We find that only very young starburst galaxy models are consistent with the data having both blue optical colors and a pronounced submm emission .
For each host we are able to construct a model consistent with the short- and long-wavelength parts of the spectra .
We find galaxy ages ranging from 0.09 to 2.0 Gyrs and star formation rates ranging from 138 to 380 M _ { \odot } yr ^ { -1 } .