Fig. 9

Relative abundance of 20 bacterial families. The abundance of major bacterial families was measured in samples comparing bronchoalveolar lavage fluid from rats exposed to (a) clean air (CON) and biomass fuel (BMF), (b) CON and motor vehicle exhaust (MVE), and (c) BMF and MVE. The value of zero indicates a similar percentage contribution of the bacterial family in any two groups. A positive value for a bacterial family indicates higher percent relative abundance in the group on the right, and a negative value indicates higher abundance in the group on the left. * p < 0.05, ** p < 0.01