Impact of oil-extraction/port activities on distribution and exchange of PAHs/APAHs/NPAHs/OPAHs in water and sediment of the Yellow River Delta, China

Abstract

The Yellow River Delta (YRD) is rich in oil, natural gas, and land resources. With the expansion of an important oil production base in North China, the increased discharge of Polycyclic aromatic hydrocarbons (PAHs) and alkylated/nitrated/oxygenated PAHs (APAHs/NPAHs/OPAHs) into the Yellow River poses a potential risk to the aquatic ecosystem and human health. A total of 42 samples were gathered from trunk streams and tributaries within the YRD region during the wet and dry seasons, and 19 PAHs, 5 APAHs, 16 NPAHs, and 7 OPAHs were measured. The concentrations of ƩPAHs, ƩAPAHs, ƩNPAHs and ƩOPAHs ranged between 29 and 620 ng/L, 6.9–81 ng/L, 0.64–9.0 ng/L, and 7.2–81 ng/L in water, respectively, and 27–420 ng/g, 5.1–130 ng/g, 0.19–1.8 ng/g and 3.9–51 ng/g in sediment, respectively. The oil extraction activities resulted in an increased presence of middle-high molecular weight PAHs and APAHs in sediment, and port activities had a notable influence on the proportion of 1-Methylpyrene in both water and sediments. The fugacity fraction analysis suggested that sediments was a secondary source of OPAHs, while benzo[k]fluoranthene, benzo[e]pyrene, benzo[a]pyrene, and 5-methylchrysene migrated from water to sediment. The main contributors to PAHs, APAHs, NPAHs, and OPAHs in water and sediment were combustion and petroleum sources. Compared to water, sediment displayed a heightened ecological risk associated with PAHs, APAHs, NPAHs, and OPAHs. And adults residing in the YRD region were at higher risk of cancer than children which deserve special attention.