By positional matching to the catalogue of Galactic Ring Survey molecular clouds , we have derived distances to 793 Bolocam Galactic Plane Survey ( BGPS ) sources out of a possible 806 located within the region defined by Galactic longitudes l = 28.5 \degr to 31.5 \degr and latitudes \mid b \mid \leq 1 \degr .
This section of the Galactic Plane contains several major features of Galactic structure at different distances , mainly mid-arm sections of the Perseus and Sagittarius spiral arms and the tangent of the Scutum-Centarus arm , which is coincident with the end of the Galactic Long Bar .
By utilising the catalogued cloud distances plus new kinematic distance determinations , we are able to separate the dense BGPS clumps into these three main line-of-sight components to look for variations in star-formation properties that might be related to the different Galactic environments .
We find no evidence of any difference in either the clump mass function or the average clump formation efficiency ( CFE ) between these components that might be attributed to environmental effects on scales comparable to Galactic-structure features .

Despite having a very high star-formation rate , and containing at least one cloud with a very high CFE , the star formation associated with the Scutum-Centarus tangent does not appear to be in any way abnormal or different to that in the other two spiral-arm sections .
Large variations in the CFE are found on the scale of individual clouds , however , which may be due to local triggering agents as opposed to the large-scale Galactic structure .