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Planar laser-induced fluorescence (PLIF) was used to study the characteristics of pollutant mixing and transport in wakes behind peninsula-type bodies. Fluorescein sodium was introduced 40 cm upstream of the peninsula as a tracer. The concentration field was measured behind semicircula-shape and sinusoid-shape peninsulas for steady inlet flows for a distance of seven radii downstream of the bodies. Analysis of the mean concentration and root mean square concentration fields showed that two factors mainly affected the concentration field in the near wake, the convection of pollutants with the main flow and the entrainment in the mixing shear layer. The impact of the shape on the concentration distribution is complex because of these two factors. In the present experiments, the semicircular peninsula caused better pollutant mixing, while the sinusoidal peninsula resulted in higher concentrations in the near wake region.