asked the Minister for Finance what study, if any, has been made of the effect of atmospheric pollution on ancient stonework with particular reference to dangers to such monuments located near areas of heavy motor traffic and if he will make a statement on the matter.
Written Answers. - Atmospheric Pollution.
260.
The Commissioners of Public Works have made studies and are continuing to do so on various aspects of deterioration of ancient stonework due to weathering and atmospheric pollution. In addition they have available the results of many studies made by other people on the problem.
The principal effect of atmospheric pollution is surface deterioration from chemical attack. Each case has to be dealt with on its merits according to the nature of the stone and severity of the attack. A successful treatment involves using a chemical wash to bond the surface and harden the stone and then keeping the surface as clean possible.
However, the main danger to ancient stonework located near areas of heavy motor traffic is vibration, which causes the joints to open leading to the penetration of the interior of the stonework by water and harmful salts. The only way to prevent this is regular inspection followed by any maintenance works found necessary.