  The presence of nuclear medium and collective phenomena which involve several
nucleons modify the parton distribution functions of nuclei (nPDFs) compared to
those of a free nucleon. These modifications have been investigated by
different groups using global analyses of high energy nuclear reaction world
data resulting in modern nPDF parametrizations with error estimates, such as
EPS09(s), HKN07 and nDS. These phenomenological nPDF sets roughly agree within
their uncertainty bands, but have antiquarks for large-$x$ and gluons for the
whole $x$-range poorly constrained by the available data. In the kinematics
accessible at the LHC this has negative impact on the interpretation of the
heavy-ion collision data, especially for the $p + A$ benchmarking runs. The EMC
region is also sensitive to the proper definition of $x$, where the nuclear
binding effects have to be taken into account, and for heavy nuclei one also
needs to take into account that a fraction of the nucleus momentum is carried
by the equivalent photons which modifies the momentum sum rule. We study how
these effects affect the predictions for the nuclear modification ratios at the
LHC kinematics using a model where we combine theoretical input for the leading
twist nuclear shadowing (the FGS model) and the EKS98s/EPS09s nPDF set where
the spatial dependence is formulated as a power series of the nuclear thickness
functions $T_A$.
