The enhanced deterioration of the cultural heritage monuments due to air pollution

Atmospheric pollution is an accelerating factor in the material deterioration of buildings and other structures as well as objects of cultural heritage; this is exemplified by three papers being published round about now in this journal (Chapoulie et al. 2008; Aulinas et al. 2009; Harrison et al. accepted for Environ Sci Pollut Res 2009) The study of the corrosive effects of gaseous SO2, NOx, O3, HNO3, particulate matter, and acid rainfall in combination with climatic parameters (the latter is influencing the carbonization rate) are of crucial importance, especially for mega-cities like Athens with unique historic monuments (Cartalis and Varotsos 1994). Greece (University of Athens, Faculty of Physics) has been involved in the European research project MULTIASSESS when exposure started at one test site in Athens in 2002 near the Acropolis which was formally proclaimed as the pre-eminent monument on the European Cultural Heritage list of monuments on 26 March 2007. One of the principal results obtained from the MULTIASSESS experimental campaign is the comparison of nitric acid concentration measured at the Athens station with that monitored at other historic cities in Europe (Ferm et al. 2005; Final Report 2005). This is presented in Fig. 1. Black columns and black and white columns denote, respectively, the cities and rural areas (background stations) where observation stations are located. The weathering (erosion) rate of stone types is determined by their compositional/physical properties. Figure 2 shows the surface recession rates for natural stone materials for 1and 2-year exposure. The surface recession differs from one stone type to another exposed to the same conditions depicting different weathering processes prevailing in each test site. As expected, the presence of air pollution increases the rate of natural weathering by about one to two times. Another important finding is that there is an increase in recession rates in the second year exposure at all test sites by one to two times, with exceptions for the weakest materials, Baumberger sandstone and Saaremaa dolomite, which showed three times increase, and moderately sensitive, namely Gotland sandstone, Portland limestone and Carrara marble (Final Report 2005; Ferm et al. 2006). The International Co-operative Programme on Effects on Materials including Historic and Cultural Monuments (ICP Materials) is being performed within the United Nations and the Economic Commission for Europe (UN/ECE) Convention in Geneva on Long-Range Transboundary Air Pollutants (LRTAP) with Greece as one of the signatories. The aim of the programme is to perform a quantitative evaluation of the effect of sulphur pollutants in combination with NOx and other pollutants as well as climatic parameters on the atmospheric corrosion of important materials and materials used in historical and cultural monuments. The two main objectives are the assessment of (a) dose–response functions (used for the calculation of deterioration rates) based on long-term exposures and (b) trend analysis based on repeated 1-year exposures (Kucera et al. 2005). This assessment is performed by statistical analysis of data on corrosion of materials and measurements of the environment. ATask Force is organising the programme with Sweden Environ Sci Pollut Res (2009) 16:590–592 DOI 10.1007/s11356-009-0114-8