Sedimentary records of PAHs in a sediment core from tidal flat of Haizhou Bay, China

The concentrations and depositional fluxes of polycyclic aromatic hydrocarbons (PAHs) were investigated in a dated sediment core collected from a tidal flat in Haizhou Bay, China. The USEPA's 16 priority PAH concentrations ranged from 72.51 ng g− 1 dw in 1969 to 805.21 ng g− 1 dw in 2010, while the deposition fluxes were in the range of 102.36-861.02 ng cm− 2 yr− 1. The PAH concentrations and fluxes changed dramatically with depth, suggesting changes in energy usage and corresponding closely with the historical economic development of eastern China. The levels of PAHs slightly increased from the late 1970s, following China's “Reform and Open” policy of 1978; however, a drastic increase in the concentration of PAHs observed in 1990 was indicative of the rapid growth in coal and petroleum incomplete combustion byproducts, which was associated with the increase in economic development in this area. Furthermore, isomer ratio analysis and principle component analysis revealed the main anthropogenic pyrolytic source that causes PAH contamination in the coastal sediment.

► We have confirmed that sedimentary PAH fluxes in tidal flat from Haizhou Bay were higher than in the continental shelf. ► The accumulation rates of pyrogenic PAHs have significantly increased in the Haizhou Bay in the recent decades. ► The high molecular weight PAHs have predominated in Haizhou Bays in the recent years.