Organic constituents in atmospheric fallout in the Tokyo area

Fine Particulate Organic Material at Meadview During the Project MOHAVE Summer Intensive Study

“…The higher concentrations of <C 20 acids as compared to >C 20 acids at Meadview in the summer sampling program reported in this study is consistent with the relative concentrations of these acids observed in sampling at Rubidoux, east of Los Angeles. 24 The higher concentrations of fatty acids in the summer may be due, in part, to the secondary formation of these lower molecular weight n-fatty acids by atmospheric reactions.…”

“…The mass median carbon number for n-alkanes has been found to be < _C 19 from diesel or gasoline fuels and C 24 from auto exhaust and diesel soot. 20 The n-alkane profiles in this study (Figure 9) can be divided into two groups for both composite samples, giving Gaussian distributions from C 13 to C 20 and from C 21 to C 28 . Both of these series have no odd or even carbon number predominance.…”

“…Principle natural biogenic sources are emissions from natural fires, gases emitted from and particles shed by plants, and the suspension of pollen, microorganisms and insect parts. [19][20][21] The relative distribution of n-alkanes among homologs of different molecular weights provides some information about the possible sources that contribute to atmospheric samples. Biogenic n-alkanes exhibit a strong odd carbon number predominance (with high concentrations of C 29 , C 31 , and C 33 nalkanes) but the emissions of n-alkanes from the burning of vegetation or fossil fuels have no odd or even carbon number preference.…”

“…However, the C 12 , C 14 , C 16 , and C 18 acids are present in the higher concentrations. The higher molecular weight n-fatty acids, >C 20 , have low concentrations. These observations suggest that the principle origin of airborne n-fatty acids at Meadview come from anthropogenic sources.…”

“…Rogge et al 24 have shown that the n-fatty acids <C 20 have enhanced emission rates from urban areas during the spring and summer, and n-fatty acids > _C 20 have enhanced emission rates during the winter. The higher concentrations of <C 20 acids as compared to >C 20 acids at Meadview in the summer sampling program reported in this study is consistent with the relative concentrations of these acids observed in sampling at Rubidoux, east of Los Angeles.…”