  Resolving the environments of massive stars is crucial for understanding
their formation mechanisms and their impact on galaxy evolution. An important
open question is whether massive stars found in diffuse regions outside spiral
arms formed in-situ or migrated there after forming in denser environments. To
address this question, we use multi-resolution measurements of extinction in
the Andromeda Galaxy (M31) to probe the ISM surrounding massive stars across
galactic environments.
  We construct a catalog of 42,107 main-sequence massive star candidates ($M
\geq 8 M_{\odot}$) using resolved stellar photometry from the Panchromatic
Hubble Andromeda Treasury (PHAT) program, plus stellar and dust model fits from
the Bayesian Extinction and Stellar Tool (BEAST). We quantify galactic
environments by computing surrounding stellar densities of massive stars using
Kernel Density Estimation. We then compare high-resolution line-of-sight
extinction estimates from the BEAST with 25-pc resolution dust maps from PHAT,
measuring the total column density distribution of extinction.
  Our key finding is that, although the average total column density of dust
increases with the density of massive stars, the average line-of-sight
extinction towards massive stars remains constant across all environments. This
suggests that massive stars have a uniform amount of dust in their immediate
environment, regardless of their location in the galaxy. One possible
explanation for these findings is that small molecular clouds are still capable
of forming massive stars, even if they are not resolvable at 25-pc. These
results indicate that massive stars are forming in the sparse regions of M31,
as opposed to migrating there.
