  The conditions under which noncommutative quantum mechanics and the Landau
problem are equivalent theories is explored. If the potential in noncommutative
quantum mechanics is chosen as $V= \Omega \aleph$ with $\aleph$ defined in the
text, then for the value ${\tilde \theta} = 0.22 \times 10^{-11} cm^2$ (that
measures the noncommutative effects of the space), the Landau problem and
noncommutative quantum mechanics are equivalent theories in the lowest Landau
level. For other systems one can find differents values for ${\tilde \theta}$
and, therefore, the possible bounds for ${\tilde \theta}$ should be searched in
a physical independent scenario. This last fact could explain the differents
bounds for $\tilde \theta$ found in the literature.
