  Effects of impurities and disorder on transport properties by electronic
quasiparticles in superconducting iron pnictides are theoretically considered.
The most prominent new features compared to the case of pure material should
appear at high enough impurity concentration when a specific narrow band of
conducting quasiparticle states can develop within the superconducting gap,
around the position of localized impurity level by a single impurity center.
The predicted specific threshold effects in the frequency dependent optical
conductivity and temperature dependent thermal conductivity and also in Seebeck
and Peltier coefficients can have interesting potentialities for practical
applications.
