Carcinogenic PAH compounds in Delhi ranged between 9.4 and 60.9 ng/m3 during 1999–2000 with higher values recorded in winter56. At Kolkata59, the sum of 12 PAHsranged from 22.91 to 190.96 ng/m3 in SPM during 1994.
In Coimbatore60, a total of 13 PAHs in PM10 ranged between 20 and 172 ng/m3, with an average 90.37 ± 57.4 ng/m3 during 2001. These levels are apparently manifold higher than the European standards.