  On the basis of general theoretical results developed previously in [I. M.
Sokolov et al., J. Exp. Theor. Phys. 112, 246 (2011)], we analyze spontaneous
decay of a single atom inside cold atomic clouds under conditions when the
averaged interatomic separation is less or comparable with the wavelength of
quasi resonant radiation. Beyond the decay dynamics we analyze shifts of
resonance as well as distortion of the spectral shape of the atomic transition.
