Distribution and source differentiation of PAHs and PCBs among size and density fractions in contaminated harbor sediment particles and their implications in toxicological assessment

► PAHs in the low density fraction were much more effective in source recognition. ► HCA of PAH revealed differences between locations and among size fractions. ► TEQPCB and TEQPAH in low density particle were much higher (up to 170 and 273 times). ► Fine particles PAHs were mainly from pyrogenic while coarse from petroleum source.