ABSTRACT

The black buildings that were for so long a legacy of post industrial revolution cities have, in many cases, been cleaned. Atmospheric pollution, dominated by sulphur dioxide (SO2) from industry and domestic fuel burning – long known to be the cause of the darkness – has been dramatically reduced. This does not mean that urban environments are clean, however. Researchers now have new questions to answer – why are buildings still getting dirty? Are they still being degraded at a faster rate than natural weathering would act? Are the same sources to blame or does policy need to target different emissions?