INFS 423 Preservation of Information Resources Session 3 – Factors of Deterioration Lecturer: Mr. Michael Allotey , Dept. of Information Studies Contact Information: mallotey@ug.edu.gh College of Education School of Continuing and Distance Education 2015/2016 – 2017/2018
Session Overview In this Session, I will be introducing you to very critical factors that exist in the environment and for that matter the storage environment of documents which are responsible for document deterioration. After the general introduction to the factors we, will concentrate on temperature and humidity, indicating to you how they can cause damage to information resources and how they can influence the longevity of documents. I will finally introduce you to the various steps you can take to provide congenial storage and use environments for your information resources. Slide 2
Learning Objectives By the end of this section, you should have learned: • The environmental factors that cause document deterioration. • How temperature and humidity cause damage to documents. • How to monitor temperature and humidity in your storage area. • How to control temperature and humidity. Slide 3
Session Outline The key topics to be covered in the session are as follows: • Topic One: Deterioration of Documents • Topic Two: Factors of Document deterioration (Rate of Document Deterioration) • Topic Three: Environmental Factors of Deterioration (Types of Deterioration) • Topic Four: Chemical Deterioration Slide 4
Reading List Akussah, H. (2011). Preservation of Documents. Department of Information Studies, Legon, NAB Superior Services. Gorman, G. E., & Shep, S. J. (2006). Preservation management for libraries, archives and museums. London: Facet Pub. Adcock, E.P. (2000). Principles for the care of handling of Library Materials. Washington, D.C., IFAPAC. Swartburg , S. G. (1983). “Conservation Library.” A Handbook of use and care of traditional materials. Connecticut: Greenwood Press, 1983. Feather, J. (2004). Managing preservation for libraries and archives: current practice and future developments. Aldershot, Hants, England, Ashgate Publishing. Slide 5
Topic One DETERIORATION OF DOCUMENTS Slide 6
Deterioration of Documents • Deterioration can simply be defined as the degradation of the quality of documentary materials. • It can also be defined as any activity that results in degradation of the quality of documentary materials. • Documentary materials are made up of organic substances. Examples are paper, audio-visuals, etc. These organic substances undergo natural aging and will ultimately deteriorate no matter the protection given to them. Natural aging is an evitable process. Slide 7
Topic Two FACTORS OF DOCUMENT DETERIORATION Slide 8
Factors of Document Deterioration The rate of document deterioration is dependent on the following factors: INTERNAL FACTORS EXTERNAL FACTORS Inherent stability • Environmental factors of the medium • Storage Conditions (quality of medium. • Handling Procedures Slide 9
Inherent stability of the medium Inherent stability refers to the quality of the medium and the method of documentation. Some organic materials whose chemical make ups are inherently unstable, will age more quickly than others stored in exactly the same environment. Slide 10
Topic Three ENVIRONMENTAL FACTORS OF DOCUMENT DETERIORATION Slide 11
Environmental Factors of Document Deterioration • Temperature • Biological Agents – Fungi • Humidity – Insects • Light (Radiant – Rodents Energy) • Human beings • Pollution • Disasters Slide 12
Types of Deterioration Type of Deterioration Environmental Factors Responsible Chemical Deterioration Temperature, Humidity, Light and Pollution. Biological Deterioration Rodents, fungus and Insects Physical Human beings /MechanicalDeterioration Deterioration through Disasters Natural and Man-made Disasters Slide 13
Activity 3.1 Visit a public library or a public archives close to you. Describe the storage environment, indicating the probable factors that can shorten the lifespan of the documents stored in them. Slide 14
Topic Four CHEMICAL DETERIORATION Slide 15
Chemical Deterioration Chemical deterioration is document degradation which emanates from chemical activities ( reactions) which result in the introduction of various forms of acidic compounds into the fabric of a document – particularly paper documents. Chemical Deterioration can result mainly from the following elements: Temperature | Humidity | Light | Pollution Slide 16
Deterioration Caused by Temperature Temperature can be defined as the level of heat in a substance, body or environment. That is, the degree of hotness or coldness of the environment and for that matter the storage environment. High temperatures speed up chemical reactions in documents whiles low temperatures slow it down. It is estimated that the useful life of paper is reduced by half for every 10 degrees Celsius increase in temperature and doubled for every 10 degrees Celsius decrease. Slide 17
Impact of Temperature on Documentary Materials • At high temperatures, chemical reactions are speeded up ( For every 18 o F increase in temperature, chemical activity in most substances double). Acid is introduced at a faster rate, hydrolysis takes place and documents get decomposed – they become brittle, cracky and easily break at a touch. Slide 18
Impact of Temperature on Documentary Materials • Estimated that the useful life of a paper document is reduced appreciably with a constantly high temperature. • At high temperature, film documents buckle at the edges, plastic base documents warp. • At high temperature, desiccation takes place. Slide 19
Impact of Temperature on Documentary Materials • Fluctuating temperatures (cycling) are the most dangerous for documents. They result in expansion and contraction – documents disintegrate more easily. Fluctuations should be prevented by controlling the use of air conditioners. In the absence of air conditioners, windows should be opened for air circulation. Slide 20
Recommended Temperatures • For Paper Documents – 20 0 C ± 2 0 C • For Film and Electronic Documents – 18 0 C ± 2 0 c • These must be kept as close to constant as possible. Slide 21
Control of Temperature • Temperature can be controlled through the following: – Air Conditioning – Good Ventilation Slide 22
Monitoring Temperature • Daily readings must be taken using a thermometer. • Readings must be recorded and consolidated to determine trends. Slide 23
Deterioration Caused by Humidity Humidity can be defined as the amount of water vapour in the air. There are three types of humidity of concern to information managers: • absolute humidity • ambient humidity, and • relative humidity. Slide 24
Absolute Humidity • This is the amount of water vapour or moisture in a given volume of air at a given temperature at a particular time. Slide 25
Ambient Humidity This is the amount of moisture in the immediate vicinity of an object. As ambient conditions change, the temperature and moisture content of collections change as well. Slide 26
Relative Humidity (RH) • This is defined as the amount of water vapour in a volume of air at a given temperature expressed as a percentage of the maximum amount that air can hold at the same temperature. • Relative humidity is crucial because of its relationship with temperature and chemical activity and the consequent physical effect on organic materials. It also changes with some factors in the environment. The warmer the air, the more water vapour it is capable of holding and as a result RH decreases. Slide 27
Damage Caused by Temperature and Humidity Temperature and humidity in an information centre must be considered together. They are bedfellows and therefore work together to preserve or destroy documentary materials: • At high humidity, paper documents absorb moisture and therefore get stuck to each other. • At high humidity levels and in combination with high temperatures, fungus growth and insect infestation are encouraged. Slide 28
Damage Caused by Temperature and Humidity • A low temperature in itself does little damage to books, but a high temperature coupled with a low humidity will dry out paper, adhesives and leather bindings. Desiccated paper becomes brittle and can break and crumble as it is handled. • Under conditions of high humidity, water soluble inks can smudge, feather or run and coated papers gets stuck to each other. • Fluctuation in temperature and humidity (Cycling) must be avoided. It causes internal stress and instability of the fibres of paper due to the contraction and expansion, thus breaking the bond to bond holding of the paper. Slide 29
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