Organics in Anthropogenically Influenced, and Aged. Aerosol Particles

Particles collected in regions influenced by anthropogenic emissions and those in aged air masses where there has been ample opportunity for oxidation are even more complex than those in remote regions. Thus, they may contain not only the organics from biogenic emissions but also complex organics that either have been directly emitted from sources associated with human activities or have been formed in air from reactions of primary emissions. 

FIGURE 9.46 Some organics from petroleum that are found in tropospheric particles (adapted from Simoneit el at., 1988). 

FIGURE 9.47 Distribution of 2-niethyl (i iso) and 3-methyl (a anteiso) alkanes measured in (a) cigarette smoke, (b) particles from abrasion of leaves typical of the Los Angeles area, and (c) annual average concentrations measured in three locations in southern California in 1982 (adapted from Rogge et al., 1994). 

In addition, the /-C33 component is relatively more important in the leaf abrasion particles. Similarly, Kavouras et al. (1998) have shown that in addition to the concentrations and ratios of the iso- and anteiso-alkanes, there are other markers associated with the alkanes in cigarette smoke. For example, the CPI for cigarette smoke was measured to be 3.44 compared to 1.41-1.66 for particles in urban and suburban areas. (The CPI for rural areas was 4.53, reflecting the contribution from plant waxes.) 

An idea of the complexity of the compounds found in air can be seen from the work of Yokouchi and 

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