“…High correlations with hopanes, in addition to OC and PAHs, have also been reported in some studies [12,15,26,42,61,63], while Shirmohammadi et al [27] found high correlations with hopanes, n-alkanes, and organic acids (phthalic, succinic, and glutaric). Differently from above, in Perrone et al [44], the methanol-soluble DTT activity of PM exhibited negative correlations with most chemical constituents including n-alkanes, being positively correlated mainly with global radiation, which was considered as a proxy for secondary oxidizing organics.…”