  We show how macroscopic manifestations of $P$ (and $T$) symmetry breaking can
arise in a simple system subject to Aharonov-Bohm interactions. Specifically,
we study the conductivity of a gas of charged particles moving through a dilute
array of flux tubes. The interaction of the electrons with the flux tubes is
taken to be of a purely Aharonov-Bohm type. We find that the system exhibits a
non-zero transverse conductivity, i.e., a spontaneous Hall effect. This is in
contrast with the fact that the cross sections for both scattering and
bremsstrahlung (soft photon emission) of a single electron from a flux tube are
invariant under reflections. We argue that the asymmetry in the conductivity
coefficients arises from many-body effects. On the other hand, the transverse
conductivity has the same dependence on universal constants that appears in the
Quantum Hall Effect, a result that we relate to the validity of the Mean Field
approximation.
