High-Resolution Record of Pyrogenic Polycyclic Aromatic Hydrocarbon Deposition during the 20th Century

Abstract

A high-resolution record of polycyclic aromatic hydrocarbon (PAH) deposition in Rhode Island over the past ∼180 years was constructed using a sediment core from the anoxic Pettaquamscutt River basin. The record showed significantly more structure than has hitherto been reported and revealed four distinct maxima in PAH flux. The characteristic increase in PAH flux at the turn of the 20th century was captured in detail, leading to an initial maximum prior to the Great Depression. The overall peak in PAH flux in the 1950s was followed by a maximum that immediately preceded the 1973 Organization of Petroleum Exporting Countries (OPEC) oil embargo. During the most recent portion of the record, an abrupt increase in PAH flux between 1996 and 1999 has been found to follow a period of near constant fluxes. Because source-diagnostic ratios indicate that petrogenic inputs are minor throughout the record, these trends are interpreted in terms of past variations in the magnitude and type of combustion processes. For the most recent PAH maximum, energy consumption data suggest that diesel fuel combustion, and hence traffic of heavier vehicles, is the most probable cause for the increase in PAH flux. Systematic variations in the relative abundance of individual PAHs in conjunction with the above changes in flux are interpreted in relation to the evolution of combustion processes. Coronene, retene, and perylene are notable exceptions, exhibiting unique down-core profiles.

Polycyclic aromatic hydrocarbons (PAHs) in continental shelf sediment of China: Implications for anthropogenic influences on coastal marine environment

“…The excellent correlations (r 2 ¼ 0.83e0.92, p ¼ 0.01e0.03; Table S4) between the concentrations of sedimentary peylene and anthropogenic PAHs in the ECS inner shelf suggested possible anthropogenic sources. However, previous studies excluded anthropogenic activities as the possible sources because the historical trend of perylene recorded in sediment cores differed from those of anthropogenic PAHs (Lima et al, 2003;Silliman et al, 1998). Different historical records of perylene and anthropogenic PAHs were also observed in the ECS inner shelf (Fig.…”

Sedimentary record of hydrophobic organic compounds in relation to regional economic development: A study of Taihu Lake, East China

“…PAHs, produced mainly from the incomplete combustion of fossil fuels, are good indicator of anthropogenic activities (Lima et al, 2003;Liu et al, 2005;Van Metre et al, 2000). In the last two decades, the Taihu Lake region has undergone rapid economic 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 development, and the Suzhou-Wuxi-Changzhou city region in southern Jiangsu is one of the most developed regions around the lake, with flourishing economy and the highest level of urbanization.…”

“…On a global scale, sedimentary PAH displayed decreasing trends in the 1970s and 1980s (Hites et al, 1997;Simcik et al, 1996;Yamashita et al, 2000), owing to the transition from home heating with coal to the use of oil and natural gas, as well as the improved combustion efficiencies in power generation. However, sedimentary PAHs have actually increased in some fast developing regions, due to rapid urbanization and increasing demand for energy consumption (Lima et al, 2003;Liu et al, 2005;Van Metre et al, 2000).…”

Sedimentary loadings and ecological significance of polycyclic aromatic hydrocarbons in a typical mariculture zone of South China

“…These observations indicate different input sources for perylene and other 5-6 ring parent compounds. Previous studies 29,30 suggest that sedimentary perylene was mainly generated from combustion of fossil fuel and biomass, as well as from natural diagenetic processes of biogenic precursors. A relative abundance of perylene greater than 10% of the sum of 5-ring PAH isomers suggests a diagenetic origin.…”