Deterioration of the physical condition of art objects

Art objects: sculpture, architecture and paintings deteriorate naturally with the passage of time. This deterioration is considerably aggravated by air pollution, particularly in modern cities. Inappropriate air-conditioning and heating, prolonged dampness, mould, insects, rough handling and transportation (to exhibitions), together with the effects of natural disasters (such as fire or flood) and bombardment in time of war, all lead to a diminution in the quality of extant works of art.