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close this book Prevention and treatment of mold in library collections with an emphasis on tropical climates: A RAMP study
View the document Preface
View the document Acknowledgements
close this folder 1. Introduction
View the document 1.1 Climate
View the document 1.2 Materials
View the document 1.3 Modifying the environment
View the document Literature cited
close this folder 2. Mold
View the document 2.1 Structure of mold
close this folder 2.2 Environmental and nutritional factors in growth and survival
View the document 2.2.1 Temperature
View the document 2.2.2 Moisture
View the document 2.2.3 Nutrients
View the document Literature cited
close this folder 3. Implications for library materials
close this folder 3.1 Vulnerability of materials
View the document 3.1.1 Paper - cellulose, sizes, coatings
View the document 3.1.2 Bookcloth
View the document 3.1.3 Leather
View the document 3.1.4 Adhesives
View the document 3.1.5 Film and related materials
close this folder 3.2 Environmental factors
View the document 3.2.1 Circulation
View the document 3.2.2 Relative humidity
View the document 3.2.3 Temperature
View the document Literature cited
close this folder 4. Prevention
close this folder 4.1 Building design and modification
View the document 4.1.1 Location
View the document 4.1.2 Structural considerations in environmental modification
close this folder 4.2 Interior modifications in existing facilities
View the document 4.2.1 Location of stack and storage areas
View the document 4.2.2 Stack arrangement
View the document 4.2.3 Localized environmental modification
View the document 4.2.4 Creating microclimates in cabinets and cases
View the document 4.3 Stack maintenance
View the document Literature cited
close this folder 5. Fungicides and fumigation
View the document 5.1 Fungicides
View the document 5.2 Fumigation
View the document 5.3 Toxicity of fumigants
View the document Literature cited
close this folder 6. Treatment
close this folder 6.1 Small outbreaks - localized high relative humidity
View the document 6.1.1 Books
View the document 6.1.2 Unbound materials (documents, maps, works of art on paper)
View the document 6.1.3 Photographs, negatives and microfilm
View the document 6.1.4 General area
close this folder 6.2 Moderate outbreaks - Major and prolonged periods of high humidity or minor flooding
View the document 6.2.1 Books
View the document 6.2.2 Unbound materials
View the document 6.2.3 Photographs, negatives and microfilm
View the document 6.2.4 General area
close this folder 6.3 Major outbreaks - Major flooding and prolonged exposure
View the document 6.3.1 Priorities and planning
View the document 6.3.2 Prevention of mold growth on site
View the document 6.3.3 Freezing
View the document 6.3.4 Drying
View the document Literature cited
close this folder 7. Equipment and supplies
View the document 7.1 Monitoring equipment
View the document 7.2 Prevention
View the document 7.3 Treatment
View the document 7.4 Emergency treatment
View the document 8. Selected bibliography

1.1 Climate

There are five major climatic groups, based on annual rainfall and temperature, with sub-groups based on variations within these parameters. Alphabetic formulas have been developed which constitute a short description of the chief characteristics of specific climates. As defined by Trewartha1 the capital letter A identifies all humid tropical climates. In Type A climates, rainfall is in excess of 60 inches per year, and is usually over 100. In some places rainfall exceeds 400 inches per year. Temperatures average 70-85 F. rarely rising over 90 F and rarely falling below 64 F. The largest of any of the principal climatic groups, Type A climates account for approximately 36% of the earth's surface. Lying in an irregular band extending from the Tropic of Cancer in the northern hemisphere to below the Tropic of Capricorn in the southern hemisphere, the humid tropics include both continental land masses and islands. In most areas, relative humidity is high year round, and mold growth in library and archival collections is a recurring problem.

Within the humid tropics (Type A), several distinct climatic types exist. These include the tropical rainforest (Af), the monsoon rainforest (Am), and the tropical savannah (As or Aw). Each climatic type requires a different approach in the modification of the library environment if damage to the collections as a result of mold growth is to be prevented.

The tropical rainforest (Af) climate has no distinctly dry season. Heavy rainfall is evenly distributed throughout the year. The yearly temperature average is between 77 and 80 F. Although the temperature average is not exceedingly high, it is quite constant, with seasonal variations of approximately 5 degrees, and daily variations of about 10 to 25 degrees. The lower night temperatures are sufficient to cause condensation of the humid air, and fog and dew are common. Winds in Af climates are light or non-existent, as these areas are usually located in the belts of calm between the tradewind latitudes. Minimal air movement, intense light and high humidity result in very little natural cooling.

In the monsoon rainforest (Am) climate, the annual rainfall, though heavy, is seasonally distributed, with definate wet and dry seasons. Am climates usually occur on a coastline, and part of the precipitation is due to the thermal effects of the coastal mountains. This is true of many tropical islands as well. Winds are stronger and more regular than those in Af regions, and the yearly temperature ranges are greater, from 12 to 14 degrees.

In the tropical savanna (As or Aw), three temperature seasons are recognizable: a cooler dry season (temperatures averaging about 80 F); a hotter dry season (temperatures sometimes exceeding 100 F) just before the rains; and a hot, wet season during the rains. The use of s or w in the designation depends on whether the dry season occurs in the summer or the winter. Wind, temperature and rainfall are all transitional, varying with the season.

The best general guide to understanding the climate of a particular area is a good atlas, which will contain numerous specialized maps of the world's climatic regions, with detailed charts on temperature and relative humidity at different seasons. More specific information is available from national and local meteorological agencies.

In tropical climates, the environmental standards so widely recommended in Europe and the United States (temperatures of 68 to 72 F and a relative humidity of 50% 5%) are difficult, if not impossible, to achieve and maintain. Due to existing building design, high energy costs, difficulties in acquiring and maintaining equipment, and the extreme year round conditions, temperature and relative humidity cannot easily be kept within these limits. In most cases, complete environmental control, which includes the regulation of temperature, humidity, air quality, and light, is possible only if included as part of the design of a new building, and if the commitment to maintain the systems is assured.

Garry Thomson, one of the foremost authorities on environmental control in museums, in a paper presented at the Asia-Pacific Seminar on Conservation of Cultural Property held in New Delhi in 1972, said: "We are told that museums cannot afford air conditioning. For important museums this is nonsense in any country where we see springing up hotels and business offices which are expensively air conditioned."2 Certainly with regard to long term goals and planning, this is true. Full control of the environment should be the long-term goal of all library and archive administrators. However, it fails to acknowledge the economic and political realities with which the museums and libraries in developing countries must deal. Until complete environmental control is possible, less comprehensive methods of modifying the existing environments must be employed.