Fig. 2

Principal coordinates plot showing the overall variation in bacterial community composition in indoor air and sources. Indoor air bacterial communities in homes (large open circles) show various degrees of overlapping with outdoor-related source environments (closed circles), indoor-related source environments (crosses), and water-related source environments (open circles). Differences in the composition of the bacterial communities were quantified using the unweighted UniFrac distance metric and symbols closer together indicate samples with more similar bacterial communities