  A QCD phase transition may reflect in a inhomogeneous decoupling surface of
hadrons produced in relativistic heavy-ion collisions. We show that due to the
non-linear dependence of the particle densities on the temperature and
baryon-chemical potential such inhomogeneities should be visible even in the
integrated, inclusive abundances. We analyze experimental data from Pb+Pb
collisions at CERN-SPS and Au+Au collisions at BNL-RHIC to determine the
amplitude of inhomogeneities.
