ABSTRACT
Weathering in action: the decay of historic buildings
The Parthenon is a temple dedicated to the goddess Athena that was built 447-32 BC on the Acropolis of Athens, Greece. During its 2,500-year history, the Parthenon has suffered damage. The Elgin Marbles, for example, once formed an outside frieze. Firm evidence now suggests that continuous damage is being caused by air pollution and that substantial harm has already been inflicted in this way. For example, the inward-facing carbonate stone surfaces of the columns and the column capitals bear black crusts or coatings. These damaged areas are not significantly wetted by rain or rain runoff, although acid precipitation may do some harm. The coatings seem to be caused by sulphur dioxide uptake, in the presence of moisture, on the stone surface. Once on the moist surface, the sulphur dioxide is converted to sulphuric acid, which in turn results in the formation of a layer of gypsum. Researchers are undecided about the best way of retarding and remedying this type of air pollution damage.
