Sources and distribution of aliphatic and polycyclic aromatic hydrocarbons in Yellow River Delta Nature Reserve, China

► Sources and distribution of petroleum hydrocarbon in Yellow River Delta National Nature Reserve (YRDNNR) were analyzed. ► Petroleum pollution in sediments of YRDNNR was relatively low or moderate. ► Petroleum pollution in Core Area and Buffer Area was weaker than that of Experimental Area. ► Pyrolytic input may be a major source of PAHs in YRDNNR. ► Petrogenic inputs were more apparent at some sites due to oil exploration of Shengli Oilfield. Sediment samples collected from the Core Area, Experimental Area and Buffer Area of Yellow River Delta National Nature Reserve (YRDNNR), China, were analyzed by GC–MS in order to determine the degree of hydrocarbon contamination, and identify the sources of aliphatic hydrocarbons and PAHs. The total petroleum hydrocarbon contents of sediments were relatively low or moderate compared to world-wide locations reported to be chronically contaminated by oil. On the whole, the degree of petroleum contamination in the Core Area and Buffer Area in YRDNNR is weaker than that of the Experimental Area. The potential ecosystem risk assessment indicated that PAHs will not cause immediate adverse biological effects in the YRDNNR. Besides oil-related hydrocarbon inputs in this region, aliphatic hydrocarbon analysis showed the presence of hydrocarbons of terrestrial origin at some sampling sites, characterized by high CPI values. Based on PAH ratios and principal component analysis, pyrolytic input may be a major source of PAHs in YRDNNR sediment, while petrogenic inputs were more apparent at some sites in the Experimental Area due to oil exploration in the Shengli Oilfield.