High chemical abundances in virgo spiral galaxies?

We present evidence that spiral galaxies in the Virgo Cluster have systematically higher interstellar abundances than comparable field galaxies. This conclusion is based on spectra of H II regions in five Virgo spirals of type Sc. A possible explanation is that abundances in the field spirals are strongly affected by infall of metal-poor gas or by radial inflow of gas from the outer H I disk. These processes are inhibited in the cluster environment, and the Virgo spirals may have evolved more nearly in the manner of the closed box " simple model" of chemical evolution.