Model predicts 'shelf life' for library and archival collections

December 22, 2015

Heritage scientists at UCL have developed demographic models of decay and loss to predict when a large library or archival collection might age beyond repair.

Lead author, Professor Matija Strlic (UCL Institute for Sustainable Heritage) explained: "Although some library materials might easily survive thousands of years some have internal clocks triggering faster decay. Using the demographic models we can now easily predict how much more degradation will be induced by a hotter and more humid climate in the future, and perhaps more importantly, how this can be mitigated."

The three part report 'Damage Function for Historic Paper' published today in Heritage Science explores what makes an historical paper unfit for use, the degradation of historical documents due to handling, and how heritage resources can be managed and stored with more economical and environmental sustainability.

The team developed an equation describing how the length of cellulose, the dominant macromolecule in paper, decreases with time depending on the acidity of paper and the environmental conditions during storage. Another model described how wear and tear accumulates with instances of reading of a book or an archival folder.

The scientists looked at more than 600 historic documents from all over Europe to arrive at a general demographic model describing how ageing progresses and fitness is lost. Professor Strlic said: "We considered a heritage collection as a population of people and used census methods and ageing models to predict how a large library or archival collection might age beyond repair.

"In relation to the outcomes of the recent COP 21 climate change conference in Paris, the projected average increase of 2 degrees centigrade in the global climate will increase the rate of degradation of some heritage collections by around 50%, and a 4 degrees centigrade increase would halve their lifetime. We can either pump more energy into indoor climate control, which is evidently unsustainable, or use our demographic models to improve collection conservation and reduce energy use at the same time."

In addition to looking at the wear and tear of historic paper the reports also looked at the public's perception of the documents' fitness for use. Almost 800 members of the public in the UK, the Netherlands and the US were surveyed on what ageing and damage to heritage collections meant to them. Only 10% of those asked believe it is necessary for collection items to remain in a usable state for more than 500 years and about 50% think 100 years is enough. The level of acceptance of degradation was dependent on whether the object had an historical or personal value.

Professor Strlic added: "The public can be quite forgiving, and they often consider that if there are signs of degradation these are signs of the 'good life' the object has had."

Nancy Bell, Head of Collection Care for the National Archives, UK said: "We have shown that it is possible to optimise the preservation of a collection while reducing energy consumption, and meeting carbon reduction targets. Using the developed demography models we can manage heat and humidity more smartly during long-term storage."
-end-
The Collections Demography project was jointly funded by the UK Arts and Humanities Research Council and the Engineering and Physical Research Council through the Science and Heritage Programme. "This unique project has shown the significant benefits of support for cross-disciplinary research combining physics, social science, chemistry, conservation, environmental modelling and heritage management" said Professor May Cassar, Director of the Programme.

The project was a partnership of UCL, the UK National Archives, the US Library of Congress, the Dutch National Archives, English Heritage, and University of East Anglia.

Notes to editors:

For a copy of the paper or to speak to the researchers, please contact: The 3 part report Damage Function for Historic Paper. Part 1: Fitness for use, Part II: Wear and Tear and Part III: Isochrones and Demography of Collections are available for download on the journal Heritage Science.

About UCL (University College London)

UCL was founded in 1826. We were the first English university established after Oxford and Cambridge, the first to open up university education to those previously excluded from it, and the first to provide systematic teaching of law, architecture and medicine. We are among the world's top universities, as reflected by performance in a range of international rankings and tables. UCL currently has over 35,000 students from 150 countries and over 11,000 staff. Our annual income is more than £1 billion. http://www.ucl.ac.uk | Follow us on Twitter @uclnews | Watch our YouTube channel YouTube.com/UCLTV

University College London

Related Ageing Articles from Brightsurf:

Cell ageing can be slowed by oxidants
At high concentrations, reactive oxygen species - known as oxidants - are harmful to cells in all organisms and have been linked to ageing.

Identified a subgroup of stem cells that resists ageing and maintains muscle regeneration
For the first time the researchers have demonstrated in a study in mice that not all muscle stem cells age equally, and have identified a subgroup with greater regenerative capacity which is maintained until geriatric age.

Ultra-processed food consumption is associated with chromosomal changes linked to biological ageing
A new study has shed light on the link between the consumption of ultra-processed foods (UPF) and the shortening of telomeres; sections of chromosomes that can be used as a marker of biological age.

The CNIO pave the way for a future gene therapy to reverse pulmonary fibrosis associated with ageing
''Our results indicate that a new therapy may be developed to prevent the development of pulmonary fibrosis associated with ageing,'' says CNIO's Maria Blasco, principal investigator of the study * Lung tissue of patients with pulmonary fibrosis does not regenerate because the cells involved in lung generation have damaged telomeres, the ends of the chromosomes.

Blood iron levels could be key to slowing ageing, gene study shows
Genes linked to ageing that could help explain why some people age at different rates to others have been identified by scientists.

Circular RNA makes fruit flies live longer
The molecule influences the insulin signalling pathway and thus prolongs life

Age research: A low level of the stress hormone cortisol contributes to the ageing process
Why do we age? What exactly is happening in our bodies?

Otago research reveals how mating influences females' life history and ageing
New University of Otago research provides insight into how males influence their mates' health, growth and fertility.

How to slow down ageing?
Healthy ageing has become one of the priorities of research in Europe.

Newly confirmed biochemical mechanism in cells is key component of the anti-ageing program
Scientists from Russia, Germany and Switzerland now confirmed a mechanism in mouse, bat and naked mole rat cells -- a 'mild depolarization' of the inner mitochondrial membrane -- that is linked to ageing: Mild depolarization regulates the creation of mitochondrial reactive oxygen species (mROS) in cells and is therefore a mechanism of the anti-ageing program.

Read More: Ageing News and Ageing Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.