Polycyclic Aromatic Hydrocarbons in Soils and Recent Sediments

Abstract

Soils and recent marine sediments contain a complex polycyclic aromatic hydrocarbon assemblage. There is a high degree of similarity in the molecular weight distribution of the many series of alkyl homologs of these aromatic hydrocarbons, and this distribution varies little over a wide range of depositional environments. The evidence suggests that these hydrocarbons are formed in natural fires, are dispersed and mixed by air transport, and are eventually deposited into surface sediments. The analytical, geochemical, and environmental implications of these findings are discussed.

Reappraisal of hydrocarbon biomarkers in Archean rocks

“…Finally, the PAH and diamondoid distribution and alkylation patterns impart high thermal signatures that match the regional metamorphic grade. More specifically, a predominance of unsubstituted, condensed PAHs is characteristic of hydrothermal petroleums (29,30), ancient mineral deposits (31,32), pyrolysis and combustion products (33), and high-maturity organic matter (34). Based on extractable PAHs, the MPI-1 parameter yields calculated vitrinite reflectances (R c ) between 2.63-3.00% (SI Appendix, Table S9) (21,35) [MPI-1 = 1.5 p ð2-MeP + 3-MePÞ=ðP + 1-MeP + 9-MePÞ, where P is phenanthrene and MeP is methyl phenanthrene].…”

Polycyclic aromatic hydrocarbons in highway plants and soils. Evidence for a local distillation effect

“…Moreover, the presence of PAHs in soils has been correlated with highway traffic and cancer incidence [8]. Nonetheless, despite several reports suggesting that airborne PAHs should be transferred over great distances [9][10], the mechanisms ruling atmospheric transfer are still poorly known. A recent investigation [6] suggests that PAHs should be partitioned between air and plant as a function of ambient temperature.…”

Mini-Radiocarbon Measurements, Chemical Selectivity, and the Impact of Man on Environmental Pollution and Climate

“…The second study in figure 1 (Blumer and Youngblood, 1975) and the other, fossil fuel combustion (Hites, LaFlamme, and Farrington, 1977), are both based on chemical inference (molecular weight distributions of selected organic species). The amounts of contemporary carbon found in our measurements, which relate to sediment deposited during the last two decades, demonstrate that a fossil source was responsible for the PAH, but a biogenic source, for the metabolized fatty acids (FA) The "impact particle" study ( fig 1) is being given special emphasis because it demonstrates both the practical value of radiocarbon as a biogenic tracer and the considerable power of the method when combined with ancillary physical, chemical, and meteorologic data.…”