The moisture dependence of the conducting properties of polyaniline fi
lms doped with camphor sulfonic acid is reported. Samples characterize
d as lying in the metallic and critical regimes of the metal-insulator
transition have been studied for electrical resistivity in the temper
ature range 77-353 K under different thermal conditions. Thermal annea
ling is shown to increase the resistivity and also its temperature dep
endence. Additionally, the temperature above which the resistivity ind
icates metallic characteristics is shown to depend very sensitively on
the presence of moisture. The results are interpreted using both the
inhomogeneously and homogeneously disordered metal models.