ABSTRACT
There is often a geographical dimension. The source of damaging factors such as pollutants may be located some distance away from where damage is first detected. Some of the many factors to consider may be contradictory (e.g. access versus preservation), or synergistic in the case of increased rates of chemical degradation caused by a combination of pollution and high relative humidity. There may also be a lengthy time lag between an event and the moment when its impact is detected.
