  We consider nuclei produced in core collapse supernovae and subjected to a
high neutron flux. We show that an accelerator mass spectrometry experiment
that searched for traces of anomalous iron isotopes could set limits on the
order of $10^{-20}-10^{-25}$ on (or perhaps discover) Pauli principle violation
by neutrons. A similar search for anomalous Co isotopes could set limits in the
range $10^{-13}-10^{-18}$ on Pauli principle violation by protons. We show that
existing data on Oxygen can be used to set a limit of about $10^{-17}$ in one
proposed model of such violation.
