Validation on GEANT4 use applied to estimate transmission curves to diagnostic energies to concrete and lead

On these days, different parameters considered to estimate shielding in diagnostic radiology. One of them is the transmission of photons through different materials, since know named transmission. The transmission curve as function of different material thickness is a base to estimate shielding thickness. Commonly are used lead and concrete as shielding material in diagnostic radiology area. Data actually used on these calculations were published by Archer, Simpkin and Legare. The simulated data show estimated error lower than 9.5 % when compared to published data Archer and Simpkin to 120 kVp spectrum to shielding thickness between 0.5 and 2.0 mm. Simulated data to thicker shielding presented higher errors due the low photons fluency. Considering 90 kVp spectrum and concrete shielding the simulated data show errors lower then 20 % comparing to Legare. To thicker shielding the photon fluency makes the errors increase. The simulated data validate the GEANT4 and its low energy library on transmission estimative played to diagnostic radiology. We suggest new work on this theme and considering other materials used to build diagnostic radiological shielding in Brazil.