We show how to build up a systematic bosonic field-theory for a general
reaction-diffusion process involving hard-core particles in arbitrary
dimension. We criticize a recent approach proposed by Park, Kim and Park (Phys.
Rev. E 62 (2000)). As a testbench for our method, we show how to recover the
equivalence between asymmetric diffusion of excluding particles and the noisy
Burgers equation.Comment: 10 pages. to appear in Phys. Rev.
