Figure 2. Cluster analysis of the major CPI-PPI network showing the association of cluster 6 with MIOs, IEs, and PAHs (yellow). The cluster is composed of 487 nodes and 5,545 edges, with Ci = 22,725. The associated constituents are SiO₂, Ti, Mg, Cr, Cl, fluoranthene, and benzo[a]pyrene.