INFS 423 Preservation of Information Resources Lecture 3 Factors - - PowerPoint PPT Presentation

School of Information and Communication Studies Department of Information Studies

2018/2019

INFS 423 Preservation of Information Resources

Lecture 3 – Factors of Deterioration

Lecturer(s): Prof. Harry Akussah & Mr. Michael Allotey Contact Information: mallotey@ug.edu.gh, hakussah@ug.edu.gh

Lecture Overview

In this lecture, I will be introducing you to some critical factors in the storage environment of documents that are responsible for document deterioration. After the general introduction to these factors, we will concentrate on temperature and humidity, indicating to you how they can cause damage to documents 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 documents.

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Learning Objectives

By the end of this lecture, 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.

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Lecture Outline

The key topics to be covered in the lecture 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

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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.

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DETERIORATION OF DOCUMENTS

Topic One

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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
• f 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.

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Deterioration of Documents

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FACTORS OF DOCUMENT DETERIORATION

Topic Two

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Factors of Document Deterioration

The rate of document deterioration is dependent on the following factors:

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INTERNAL FACTORS

Inherent stability

• f the medium

(quality of medium.

EXTERNAL FACTORS

• Environmental

factors

• Storage Conditions
• Handling

Procedures

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.

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ENVIRONMENTAL FACTORS OF DOCUMENT DETERIORATION

Topic Three

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Environmental Factors of Document Deterioration

• Temperature
• Humidity
• Light (Radiant

Energy)

• Pollution
• Biological Agents

–Fungi –Insects –Rodents

• Human beings
• Disasters

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Types of Deterioration

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Type of Deterioration Environmental Factors Responsible Chemical Deterioration Temperature, Humidity, Light and Pollution. Biological Deterioration Rodents, fungus and Insects Physical /Mechanical Deterioration Human beings Deterioration through Disasters Natural and Man-made Disasters

Activity 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.

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CHEMICAL DETERIORATION

Topic Four

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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

• f a document – particularly paper documents.

Chemical Deterioration can result mainly from the following elements: Temperature | Humidity | Light | Pollution

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Deterioration Caused by Temperature

Temperature can be defined as the level of heat in a substance, body

• r environment. That is,

the degree of hotness or coldness of the environment and for that matter the storage environment.

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Deterioration Caused by Temperature

• 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.

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Impact of Temperature on Documentary Materials

• At high temperatures, chemical reactions are

speeded up ( For every 18oF 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.

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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.

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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
• pened for air circulation.

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Recommended Temperatures

• For Paper Documents – 200C ± 20C
• For Film and Electronic Documents – 180C ±

20c

• These must be kept as close to constant as

possible.

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Control of Temperature

• Temperature can be controlled through the

following:

–Air Conditioning –Good Ventilation

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Monitoring Temperature

• Daily readings must be taken using a

thermometer.

• Readings must be recorded and consolidated to

determine trends.

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Deterioration Caused by Humidity

Humidity can be defined as the amount of water vapour in the air. There are three types of humidity

• f concern to information managers:
• absolute humidity
• ambient humidity, and
• relative humidity.

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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.

• Absolute humidity has a direct relationship

with temperature

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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.

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Relative Humidity (RH)

• This is defined as the amount of water vapour/ moisture

in a volume of air at a given temperature expressed as a percentage of the maximum amount of moisture 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.

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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.

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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

• ther.
• Fluctuation in temperature and humidity (Cycling) must be
• avoided. It causes internal stress and instability of the fibres
• f paper due to the contraction and expansion, thus breaking

the bond to bond holding of the paper.

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Motoring Humidity

• Temperature and relative humidity can be measured by a

thermometer and a hygrometer respectively.

• One way to monitor temperature and relative humidity

simultaneously is to use a hygro-thermograph: an instrument that records both temperature and humidity whiles plotting a graph. This is widely used, however, unless it is regularly maintained by a trained professional, it can give false results.

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Motoring Humidity

• Another method is to use newly available electronic

testing equipment, such as data logger. This method is expensive.

• A cost effective option for monitoring is to use a

whirling hygrometer. This is usually sufficiently accurate and less expensive than the other methods.

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Control of Temperature and Humidity

• No easy solution. Because of the varied range of

documentary materials which respond differently to humidity and temperature.

• Ideally, separate storage area should be used. This is

not always the case because of the cost involved.

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Ideal Control

Control both temperature and humidity through air conditioning for 24hrs a day.

• Paper Documents 45% ±2% and 200C ± 2)
• Film + Digital Documents 35% ± 2% (180C ± 2)

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In The Absence of Air Conditioning Facilities

• Use Humidifiers and Dehumidifiers (Electronic/

Chemical).

• Windows should be widely opened to allow free

circulation of air.

• Wooden furniture should be used as this absorbs excess

moisture and gives out moisture when necessary.

• Documents should not be packed too tightly into boxes,
• n shelves or in cabinets.
• Water dripping from air conditioners should be guided

away from the storage area.

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Activity 2

Select and visit two information centres -

• ne with air-conditioning facility and the
• ther without air-conditioning facility.

Describe briefly the difference in the state

• f documents in the two centres hold.

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Summary

Having successfully completed this Session, you have learned:

• The factors that cause document deterioration
• Damages caused by temperature and humidity
• The control of temperature and humidity
• The monitoring of temperature and humidity

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References

Akussah, H. (2011). Preservation of Documents. Department

• f Information Studies, Legon, NAB Superior Services.

Gorman, G. E., & Shep, S. J. (2006). Preservation management for libraries, archives and museums. London: Facet Pub.

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