Adverse effects arising from conservation treatments on archaeological sites: theory, practice and review

Abstract

Conservation and restoration of archaeological sites developed significantly in the second half of the twentieth century, with greater emphasis in recent decades, which has led to a considerable number of interventions. Methodology of intervention has changed significantly since more interventionist measures are performed against the current criteria of minimum intervention, although what actually occurs today is a difficult balance between innovation (experimental application of new techniques and products) and minimum intervention. The debate, in the case of archaeological sites, has focused on the actions traditionally more aggressive: cleaning, consolidation or reintegration, as this is where most notable has been the restorative action throughout history. The restoration, like everything else, has been subject of trends, in relation to the appearance of new products and technologies, and today remains a discipline that widely develops experimental practice. It certainly brings great benefits and constant renewal of criteria and methodologies, but also risks by introducing new compounds that may interact negatively with original substrate, although their effects cannot be checked in the short or medium term. The lack of knowledge of the causes of decay arising from previous interventions has generated a series of continuous protection and consolidation treatments at different periods. Restorers currently must deal with decayed areas where the products, methodology or techniques used, have caused a negative effect on the original material. This paper attempts to explore the general study of effects and alterations arising from restoration treatments, as well as reviewing of scientific publications related to this issue.series of continuous protection and consolidation treatments at different periods. Restorers currently must deal with decayed areas where the products, methodology or techniques used, have caused a negative effect on the original material. This paper attempts to explore the general study of effects and alterations arising from restoration treatments, as well as reviewing of scientific publications related to this issue.