  We develop a field-quantization scheme for calculating quantum electrodynamic
effects on polarizabilities of light atomic systems. This scheme is based on
the theory of long-wavelength quantum electrodynamics of Pachucki [Phys. Rev. A
\textbf{69}, 052502 (2004)], which combines the theory of nonrelativistic
quantum electrodynamics with the Power-Zienau transformation. The external
electromagnetic field effects, including electric and magnetic multipole
polarizabilities and their relativistic and radiative corrections, are derived
using this scheme. The Coulomb-transverse-photon contributions are shown to be
zero due to parity symmetry.
