Environmental Factors Affecting the Permanence of Library Materials

Protecting library materials against the dangers of environment is a critical problem. Inadvertent misguidance on the subject could hasten damage to valuable library materials. Most librarians realize this and agree on the need for deep study of the protection of library collections against deteriorative environments. One of the more encouraging signs in the recent past is the Library of Congress brittle book project [1]. The recognition of the importance of the library materials deterioration problem at the level of the Library of Congress, the Association of Research Libraries, and the Council on Library Resources, places the matter at the echelon where adequate attention may be brought to it and the required national effort made to provide the restoration, conservation, and preventive measures required if we are to leave behind us library collections usable in the distant future. This discussion will attempt to investigate environmental factors affecting the permanence of library materials and will try to draw some concepts from the information developed that will lengthen the life and usefulness of library collections. It is the objective of this paper to emphasize that deterioration of library materials can arise from inferior operating and storage conditions over both short-term and prolonged periods. It will review some pertinent evidence relating to deterioration originating with air pollution, heat and humidity, light, and biological agents. Focusing for the most part on the environments encountered in American urban research libraries, it will emphasize the effects of temperature, humidity, and such air pollutants as ozone, sulfur dioxide, and the nitrogen oxides. Since biological attack is not usually a widespread danger in these libraries, it will be discussed briefly. These points will lead to suggestions regarding how librarians may lengthen the useful life of library materials through environmental controls including some of the details of modern airconditioning practices, criteria, and specifications.