  [Background] The "pasta" phase of nuclear matter may play an important role
in the structure and evolution of neutron stars. Recent works suggest nuclear
pasta has a high resistivity which could be explained by the presence of long
lived topological defects. The defects act as impurities that decrease thermal
and electrical conductivity of the pasta. [Purpose] To quantify how topological
defects affect transport properties of nuclear pasta and estimate this effect
using an impurity parameter $Q_{\text{imp}}$. [Methods] Contrast molecular
dynamics simulations of up to 409\,600 nucleons arranged in parallel nuclear
pasta slabs (perfect pasta) with simulations of pasta slabs connected by
topological defects (impure pasta). From these simulations compare the
viscosity and heat conductivity of perfect and impure pasta to obtain an
effective impurity parameter $Q_{\text{imp}}$ due to the presence of defects.
[Results] Both the viscosity and thermal conductivity calculated for both
perfect and impure pasta are anisotropic, peaking along directions
perpendicular to the slabs and reaching a minimum close to zero parallel to
them. In our 409\,600 nucleon simulation topological defects connecting slabs
of pasta reduce both the thermal conductivity and viscosity on average by about
37\%. We estimate an effective impurity parameter due to the defects of order
$Q_{\text{imp}}\sim30$. [Conclusions] Topological defects in the pasta phase of
nuclear matter have an effect similar to impurities in a crystal lattice. The
irregularities introduced by the defects reduce the thermal and electrical
conductivities and the viscosity of the system. This effect can be
parameterized by a large impurity parameter $Q_{\text{imp}}\sim30$.
