  High energy electron and muon neutrino propagation through the Earth has been
performed using the Monte Carlo technique. We focused our attention on the
effect of neutral current deep inelastic interactions compared to that of
charged current ones. We have found that NCs do not produce any significant
effect with respect to the case in which only CCs are considered. Therefore we
conclude that NC interactions can be neglected without considerable loss of
accuracy. When computing upward-going neutrino fluxes a simple formula
describing the transmission probability, that depends on the neutrino direction
and energy and the CC cross section, can be used to account for the Earth
shadowing effect.
