The gas to particle phase partitioning of PAHs in air is a function of
both ambient temperature and also volatility of the PAH in question.
Therefore as ambient temperature increases ,the equilibrium shifts
towards PAHs in the vapor phase. There is also some dependence, in
the short term at least, of the gas to particle partitioning ratio on the
source of emission and other atmospheric chemistry and meteorological
considerations. Some exemplar gas to particle PAH ratio measurements
are given in Table 2, showing the good correlation between the
percentage of the PAH total found in the particulate phase and both
molecular weight and vapor pressure.