S 0 2, N O , N 0 2 contents and suspended particles have been measured in the Environmental Monitoring Station installed in the Royal Palace of Madrid. The analysis of these major air pollutants has been carried out during 1994-1995. In addition, several parameters such as pressure, temperature, wind direction and speed, as well as rain were measured in the Meteorological Station emplaced at the roof of the Palace.
The main goal of this study is to evaluate the Importance of these environmental factors In order to ascertain their role in the degradation and blackening of the Palace materials. This will place a base for cleaning and other conservation tooks ofter a kinetics assessment of the behaviour of the several products involved in the restoration