Source apportionment of polycyclic aromatic hydrocarbons in surface sediment of mud areas in the East China Sea using diagnostic ratios and factor analysis

► We used the profiles of aliphatic hydrocarbons and alkyl PAHs to help and support in PAH apportionment. ► There was no significant difference in PAHs concentrations between the inner and outer shelf mud areas in the ECS. ► AHs patterns for all samples were dominated by the unresolved complex mixture (UCM). ► Factor analysis provides more detailed and valid source apportionment results than diagnostic ratio method. ► Natural gas combustion has become an important source of PAHs to the sediments from the ECS.