Radiation losses from light impurities from tokamak boundary plasmas within the last closed magnetic surface, where radial transport is of great importance for ion distribution over charge states, are estimated. "Radiation strengths", characterizing the integral intensity of radiation, are calculated for different ions of carbon, oxygen, neon and silicon. Characteristic plasma parameters in the regions, where these particles mainly radiate, are determined. A simple zero dimensional model of the heat transport at the plasma edge is proposed and the effect of the particle transfer on the detachment conditions is examined. The results are compared with experimental data from ohmic and auxiliary heated discharges in TEXTOR. Conditions necessary for the creation of a "radiating periphery" in a reactor are discussed