  The Abelian Manna model of self-organized criticality is studied on various
three-dimensional and fractal lattices. The exponents for avalanche size,
duration and area distribution of the model are obtained by using a
high-accuracy moment analysis. Together with earlier results on
lower-dimensional lattices, the present results reinforce the notion of
universality below the upper critical dimension and allow us to determine the
the coefficients of an \epsilon-expansion. Rescaling the critical exponents by
the lattice dimension and incorporating the random walker dimension, a
remarkable relation is observed, satisfied by both regular and fractal
lattices.
