Portland limestone samples were exposed at 3 sites in Littlehampton, York, and Leatherhead. Weight changes (briefly presented) indicate that inland urban loss rates for fresh limestone are now close to those associated with natural weathering, however coastal proximity enhances loss rates and also the pollution sensitivity of the loss rate. The So2 (sulphur dioxide) dependency was clearly revealed when So2 concentrations were varied on one site so that all other variables remained comparable. 2 graphs, 6 references.