Hydrocarbons in coastal sediments from the Mediterranean sea (Gulf of Fos area, France)

Application of multiple geochemical markers to investigate organic pollution in a dynamic coastal zone

“…On the one hand, the number of registered vehicles in eastern Guangdong is greater than that in western Guangdong [40], possibly resulting in higher PAH emissions from petroleum combustion or unburned residues (or both) in eastern Guangdong. This is consistent with observations of generally higher UCM, a tracer of aged petroleum residues or degraded hydrocarbons, or both [25], in the eastern (<nd-205, mean 37 mg/g) compared with the western (<nd-22, mean 9 mg/g) coastal sediments. Furthermore, the greater population density in Guangdong's eastern cities, compared with the western ones [40], is probably an important cause for the statistically higher S 25 PAH (S 26 PAH minus perylene) concentrations in the eastern (38-340, mean 158 ng/g) than in the western (20-138, mean 83 ng/g) coastal sediments (Fig.…”

“…The CPI [24][25][26][27][28][29][30][31][32][33][34] values (1.7-4.3; Supplemental Data, Table S2) in the present study were greater than 1 but lower than those of typical terrestrial higher plants (5-10) [31], suggesting additional contributions from other sources. In the present study, the addition of biogenic hydrocarbons from submerged or floating macrophytes to terrestrial plants was suggested by the aquatic macrophyte n-alkane proxy ((n-C 23 þn-C 25 )/(n-C 23 þn-C 25 þ n-C 29 þn-C 31 )) values (0.16-0.26; Supplemental Data, Table S2).…”

“…High Pr/n-C 17 (0.85-4.76, mean 2.04; Supplemental Data, Table S2) and Ph/n-C 18 (0.39-5.86, mean 1.81; Supplemental Data, Table S2) values suggest degraded oil, because isoprenoids are less susceptible to degradation than straight-chain alkanes [23]. However, the use of Pr/n-C 17 and Ph/n-C 18 values might be somewhat questionable, because pristane and phytane could also come from biogenic sources such as zooplankton and bacteria [25]. Low Pr/Ph values (0.2-0.6) were observed in sediments from Sfax, Tunisia [26], where petroleum hydrocarbons occur widely.…”

Toxicity of sediment-associated unresolved complex mixture and its impact on bioavailability of polycyclic aromatic hydrocarbons

“…Most studies on crude oil spills have focused on polycyclic aromatic hydrocarbons (PAHs), and have shown that these contaminants caused detrimental effects on various aquatic organisms [2][3][4][5][6]. Conversely, other constituents in the oil matrix, which were commonly referred to as an unresolved complex mixture (UCM) were less studied [7][8][9][10].…”

Sources and preservation of organic matter in soils of the wetlands in the Liaohe (Liao River) Delta, North China

“…High concentrations of Ph (>100 ng/g) were found at sites number 59, 63, 77, 78 and 94 in this study, indicating a significant contamination with petroleum hydrocarbon at these sites. Short-chain even number n-alkanes (such as C 16 and C 18 ) would be degraded prior to significant alternation of the counterparts, thus the values of C 18 /Ph ratios for moderate to severe biodegradation of petroleum-derived OM may be lower than 1 (Medeiros et al, 2005;Mille et al, 2007). In the present study, however, the C 18 /Ph ratios are much higher than 1, even though in those sites (59, 63, 77, 78 and 94) it had high Ph concentrations.…”