We analyze a quantum kinetic equation describing both boson and fermion pai
r production and explore analytically and numerically the solution of the n
on-Markovian kinetic equation. In the low density limit of the kinetic equa
tion we find an analytical solution for the single particle distribution fu
nction of bosons and fermions. The numerical investigation for a homogeneou
s, constant electric field shows an enhancement (bosons) or a suppression (
fermions) of the pair creation rate according to the symmetry character of
the produced particles. For strong fields non-Markovian effects are importa
nt while they disappear for weak fields. Hence it is sufficient to apply th
e low density limit for weak fields but necessary to take into account memo
ry effects for strong fields. [S0556-2821(99)04607-X].