Polycyclic Aromatic Hydrocarbons in Sediments of the Southern Basin of Lake Michigan

The southern basin of Lake Michigan is receiving polycyclic aromatic hydrocarbon (PAH) inputs from many sources. An investigation of parent PAH compounds in sediments from different depositional zones revealed concentrations ranging from 0.2–6.2μg/g dry sediment weight. The distribution of the parent PAH is distinctive of high temperature combustion sources. PAH alkyl homolog analyses showed the presence of several highly alkylated PAHs, such as retene, indicating possible inputs from paper industries, and alkylated naphthalenes, which may indicate contributions from municipal/industrial effluents and petroleum shipping activities. A subsurface concentration maximum of total parent PAHs observed in depositional zone sediments may be due to either a physical process (resuspension) or decreased anthropogenic input.