博物館等の収蔵空間における汚染ガスの簡易な特定法とその除去の構築
Storage Spaces in Museums and Libraries: Designing Simple Alternative Methods for the Source
Determination and Mitigation of Gaseous Pollutants

アルセ ヒュットマン イメ
Arce Hüttmann Imme
1. Introduction

and apply these methods.

“Preventive conservation” refers to the attempt of

The purpose of this research is to help preserve cultural

mitigating the inevitable damage that occurs to stored

heritage by investigating gaseous pollutants in museum

cultural objects in museums, libraries and the like byand library spaces as well as by developing pollutant

controllingdetection and mitigation methods for local and small

theenvironmental

conditions

andimplementing countermeasures for predictable damage

museum and library spaces.

sources.
The damage causes that are considered for preventive

2. The environmental Conditions of Costa Rican

conservation vary, but the nine common agents ofdeterioration factors according to ICOM are: 1-direct

Museums
As a case study of museums in developing countries, thephysical forces 2-thieves, vandals, and displacers 3-fireenvironmental conditions of Costa Rican museums and4-water 5-pests 6-contaminants 7-radiation 8-incorrect

their storage rooms was evaluated.

1

temperature 9-incorrect relative humidity.

Temperature

andrelativehumidity,Museums and libraries should deal with these main

UV-radiation as well as gaseous pollutants were measured

factors to ensure the preservation of their collections.

in the Costa Rican National Museum and the Costa Rican

However, not all institutions have the necessary staff andArt Museum (figures 1 and 2).

budget to do this. This is especially the case in small

The measurements were performed in two phases (phasemuseums and libraries, as well as in museums and1 from March 19th to April 2nd 2012 and phase 2 fromlibraries in developing countries. With limited resources,

August 21st to September 5th 2013).

some damage factors tend to be prioritized. For example,
simple and cost-effective alternative methods have beendeveloped to aid in the control of temperature and relative
humidity.2
Since contaminants and their detrimental effects are notdirectly perceived, they are not usually the priority forsmall museums and libraries.
However, gaseous pollutants are a serious threat to
cultural heritage, and as pollution increases and newmaterials are introduced, there is a need to revise theeffects of pollutants today up to the smallest library ormuseum.
Various countermeasures have been designed to tackle
contaminants in museums. They are divided into
detection and mitigation methods.
However, Museums and libraries with little resources(both professional and economic) cannot easily acquire
学位論文梗概集 2013

Figure 1 Costa Rican National Museum

visibleandstreet in front of the museum to enter.
Hydrogen sulphide, acetic acid, ammonia and nitrogendioxide passive dositubes were used. The results of thefound specific pollutant amounts measured with passive
dositubes in the Costa Rican Art Museum are shown intable 1.

Table 1 Passive Dositube results
Passive Dositubes 2012
Figure 2 Costa Rican Art MuseumGasMuseum Hall

Storage Room

The measurement places for the Costa Rican National

Ammonia Amount0.04 ppm

0.08 ppm

NO2 Amount0.00652 to 0.01

-Museum were 1-the Museum Hall, 2-the Textile Storage
Room and 3-the Painting and Sculpture Storage Room.
For the Costa Rican Art Museum they were 1-Outside,

All dositubes were places
ppmMarch 19th 2012
The "-" Sign signifies that these measurements were not

2-the Golden Hall(second floor), 3- the Storage Room,taken
Passive Dositubes 2013

4-the Museum Hall (first floor) and 5-Drawer#26 in theGas

Storage Room

Drawer # 26

storage room.

Ammonia Amount

0.1 ppm

0.03 ppm

From the gathered data it was observed that in general,

All dositubes were placed September 2nd 2013

the temperature conditions in these two museums are
relatively stable, ranging averages from 20°C to 24°C.

The presence of nitrogen dioxide was discovered, but

Humidity, however, was high, averaging 65-75% for alllevels do not surpass the recommended standards 3 .

measured places and reaching very extreme minimum

However, ammonia gas almost doubles these standards.

and maximum levels. Both museums have been making

While the presence of ammonia gas in the Costa Rican

efforts to install air conditioning in the storage rooms, but

Art Museum was confirmed, the source of this pollutant

it is questionable whether conditions actually improve,

can only be supposed. Concrete, persons, some sealants

since short-term fluctuations are heavier and there haveand paints are known ammonia gas sources.4

been reports of air conditioning failures.

Overall, it was found that Costa Rican museum

Visible light and UV-radiation were only measured in theconditions were stable but could be improved with theCosta Rican National Museum Hall and in the Costa

required

Rican Art Museum Storage Room. They were considered

importance of tackling gaseous pollutants is very

high for the Costa Rican Art Museum Storage Room,

important to prevent damage from happening even inconsidering that it is not an exhibition space and that

small museums. Other factors can easily be controlled, forcertain pigments and materials can be very sensitive.

example by lowering light brightness in storage rooms.

However, further research on light and UV radiation isThe great need of cooperation between museums wasneeded in this area.

discovered. While the Costa Rican National Museum

Gaseous Pollutants were measured in the Costa Rican Art

employs two conservation professionals, the Costa Rican

Museum only, using pH-strips, passive dositubes andArt Museum does not. Overall conditions could bedetection tubes.

improved by professional sharing. Besides knowledge,

It was found that while the storage room is generally
alkaline and has ammonia, the museum in the firstfloor is neutral-alkaline and in the second highly acidic.
The windows of the second floor of the museum
remain open for the day, allowing pollutants from themethods and materials have to be more easily available soknowledge.

Raising

conscienceonthethat cultural assets can be protected appropriatelyanywhere.

Summaries of Academic Theses 2013

Figure 3 The safe at the Central Library

3. Gaseous Pollutant Source Determination for
the Safe of the Central Library of the University

In a preliminary investigation, the overall presence ofof Tsukuba

ammonia in the safe was confirmed, and no organic acids

While the Central Library of the University of Tsukuba

were detected. The contrary happened inside of the box ofholds books, journals, magazines, etc., it also counts with

document ル 218-21: ammonia was not detected but

a rare books collection that includes works from variousorganic acids were. This indicated that within adifferent eras. This collection is stored in a safe located in

microspace "sub-microspaces" with completely different

the first floor.

characteristics could exist.

Former investigations had shown high amounts of organic

For these specific investigations, each selected material

acids and ammonia there. While the organic acids

was separated from its corresponding box or cover for

decreased

sampling.

withtheuse of chemical adsorption

sheets(based on activated carbon), the ammonia levels

The materials were placed in gas-barrier-bags. Then,remained high.

nitrogen gas was inserted with a pump and the bags wereThis led to an investigation aimed to detect the source ofleft for two weeks to allow off-gassing.

ammonia gases, divided into two surveys (first survey

Next, air samples were taken using ultra pure-waterfrom October 2012 to December 2012 and second survey

impingers and Tenax® tubes that were subsequently sentfrom January 2013 to February 2013). A method to selectto the Nippon Muki Company for analysis. The impinger

probable pollutants sources was developed, called thesamples were analysed with Ion Chromatography (IC)"Targeted Pollutant Source Detection Method". It would

while the Tenax® tubes were analysed with Mass

not only involve the material of the objects, but theirSpectrometry-Gas Chromatography (GC-MS).

history and context as well.

Off-gassing can be measured with other methods such as
the "Gasbag-Gastube Method" that is described in part 4.
The "Targeted Pollutant Source Detection Method" only
intends to aid in the selection of materials for sampling.
Tables 2 and 3 show the results of both surveys.
For the first survey, the previously mentioned ル 218-21
was selected for sampling. ル 120-352 was also selected
as it was a book that contained various pigments. As ル
218-21 showed extremely high amounts of acetic acid(over four times the recommended levels), this material
was wrapped in an ammonia chemical adsorption sheet
and placed in a gas-barrier-bag as a tentative
countermeasure.

Table 2: Results of the first survey(μg/m3)
Organic Gases
SampleAcetic Acid
Formic AcidBlank
28
6ル-120-352 Book50
<6ル-120-352 Cover41<6ル-218-21 Book
1,250
124
ル-218-21 Box
23537*based on toluene calibration

学位論文梗概集 2013

(CL<1)<1<1<1<1

Inorganic Acids(NO2(NO3<2<2))<2<2<2<2<2<2<2<2(SO42) <22-)<2<2<2<2Alkali(NH4+)
596
102
672

TOC*
900
49
91
5,609
1,964

Naphthalene*<640555,464
1,827

*based on toluene calibration(μTable 3: Results of the second survey
Organic Gases
SampleAcetic Acid
Formic AcidBlank
65
44
ル-120-364 Scrolls
204
48
ル-120-386 Book
89
37
ル-120-386 Cover
75
28
ル-120-364 Box
191
51(CL<1)
1<1<1<3

ル-218-21 Book

<1651

106

Inorganic Acids(NO2(NO3<2<2))<2<2<2<2<2<2<2<2<2<2(SO42) <42-)<4<4<4<4Alkali(NH4+)<179827258g/m3)
TOC*
4,643
1,208285731
2,240

Naphthalene*<8425
5060593<442,794

1,777

The fact that not the box, which was new and made out of

pollutant can be done in different ways. For thesewood, but that the book was the main source of acetic

particular experiments, GC-MS and IC was used. Theacid was remarkable. Wood is a known acetic acid

“Gasbag-Gastube Method” that is explained in chapter 4source.

5The book is in very good condition. Thecan also be used, as well as any other analysis method

possibility that it had adsorbed the acetic acid wasavailable.

considered.

Each microspace can be different, conditioning the needs

For the second survey, ル 218-21 was analysed again,and effectiveness of this method. The main contribution

showing that acetic acid off-gassing decreased to almostof it, however, is to not only consider the material, but all

half the original values. ル 120-364 was chosen for

the information regarding the stored collections, including

sampling because it was heavily deteriorated. ル 218-386

storage and restoration history.

was analysed as it had very similar characteristics to ル

From these investigations the source of ammonia gas was

120-352, except that it had not been restored. Leads on

not determined. However, important leads were provided.

the off-gassing of restoration material were expected but

Also, it was understood that the possibility that a material

not acquired.

might adsorb contaminants to desorb them later on has toThis method is useful when looking for the source of abe taken into account. Not only the material an object is

contaminant detected after a general air pollution

made of is a determining factor.

investigation.

The possibility of "sub-microspaces" within microspaces

It is based on the following five steps:

with completely different characteristics was discovered
as well.

1) Once the presence of the pollutant is confirmed,
consider the possibility of sub-microspaces with different

4. Designing an alternative Methodology forcharacteristics and analyse them apart.

determining the Presence of Gaseous Pollutants

Check boxes, packages, etc.

and finding Alternative sorbents

2) Perform an inventory of the objects considering theThe study cases of Costa Rican museums and the Central

following factors: 1- Material the objects and their

Library of the University of Tsukuba show that gaseous

respective covers/boxes are made of 2- Date of eachpollutants still exist in museum and library spaces.

object and its box or cover 3-General appearance of theIn order to help small and local museums and libraries toobjects (deterioration state, smell, etc.) 4-Storage History

deal with gaseous pollutants, their sources and mitigation(when the object entered the collection) 5- Restoration

methods, an alternative gaseous pollutant detection

History. Besides checking the records, perform visual

method using gas-barrier-bags and detection tubes, called

observation 6- Any additional information of the staff

the “Gasbag-Gastube Method” was designed.

3) With the gathered information, look for probableThis method was tested by investigating the ammonia gas

contaminant sources. Separate the objects from theirsorbing capabilities of paper material. Paper was chosen

containers (boxes or covers) when considering sources.

for two main reasons: first, to explore the possibility ofAlso, consider the possibility of adsorption.

using paper material as an alternative sorbent, as paper is4) Separate the materials using Gas-barrier-bags. Always

accessible almost everywhere and inexpensive. It has

prepare a blank when performing analysis. Analysis of the

been suggested that natural fibres (such as cellulose-based
Summaries of Academic Theses 2013

fibres) may have greater sorption capacities than othermaterial6. Understanding the sorption characteristics ofpaper material may aid local or small museums andlibraries that are in need of accessible sorbents but cannot
afford them or get to them.
Second, there was a need to understand the sorption
ability of cultural assets made out of paper. There was anindication that assets such as ル 218-21 could adsorb
acetic acid. Thus, even though a material does notnaturally off-gas a contaminant, it could adsorb anddesorb it.
Understanding the gas sorption phenomena that may
occur in an exhibition or storage space can improve thepreservation of movable heritage.
Fabriano Rosaspina, Filter Paper, Kozoshi and Usuyoshi
were the four types of paper chosen for these experiments.
A quarter of the medium-sized Japanese print standard
was selected as the target size, which was roughly
rounded to 130x100 mm. An extra set of samples wasdeteriorated with a Xenon instrument to compare new anddeteriorated paper sorption rates, considering that cultural
assets have usually undergone some deterioration.
Ammonia was selected as the pollutant gas, as it wasFigure 4 Gasbag-Gastube Method

found both in the Costa Rican Museum of Art Storage
Room and in the Rare Books Collection safe of theThe paper and ammonia experiments were divided as

University of Tsukuba. Central Library.

follows:

The “Gasbag-Gastube Method” uses gas-barrier-bags

and gas detection tubes to determine the presence andamount of pollutants of targeted objects or material.

1- Adsorption 1 (2013.8.13-2013.8.14)

Figure 4 shows an overview of the method:measured.

① The sample is placed in a gas-barrier-bag.

2-Adsorption② Nitrogen gas or pollutant gas is inserted according toRe-adsorption (2013.10.24-2013.10.25)

the experiment needs (nitrogen gas for off-gassing orThe adsorption rates of the four types of paper weredesorption and pollutant gas for adsorption experiments)

measured. After this, ammonia gas was reinserted to③ The amount of the targeted gas can be read at thesaturate the samples.

desired time with a diffusion tube or a detection tube.

3-Desorption (2013.11.1-2013.12.6)

The adsorption rates of the four paper types were2(2013.10.22-2013.10.23)

and

its

The used samples were placed in gas-barrier-bags andThis method can be used with other materials and gases

filled with nitrogen gas for desorption. Only two samples

besides paper and ammonia gas. It can also be used to seewere chosen.

if a specific object or a part of it is off-gassing pollutants

4-Adsorption of damaged paper (2013.11.5 -2013.11.6)

in small and local museums. There is a need to further

The adsorption experiments were repeated with damaged

research on the possibility of using regular air instead of

paper samples. Only two samples were chosen.

nitrogen as well as an alternative gas insertion method
instead of a pump, possibly another gas-barrier bag.

学位論文梗概集 2013

Figure 5 The results of the adsorption 2 experiment

5. Conclusions
A blank was always used when performing these

Two methods were presented in this research: Theexperiments to check if the gasbags themselves adsorbed“Targeted Pollutant Source Detection Method” wasammonia gas and to subtract any extra-adsorbed gas fromproposed to determine the source of gaseous pollutants inthe final results

microenvironments, such as cabinets, safes, etc. The

The “Gasbag-Gastube Method” provided reliable data on“Gasbag-Gastube

adsorption rates. The different paper types showedalternative method

different adsorption rates and velocities. Figure 5 shows

to easily detect the presence and amount of a contaminant.

the results of the adsorption 2 experiments. The different

This method was tested with four types of paper, and it

adsorption rates can be observed there.

was determined that paper does have adsorbing

Ammonia concentrations were measured after determinedcapabilities, although further research is necessary toamounts of time. While the concentration of ammonia gas

understand whether paper material can actually be used.

in the blank bag decreased somewhat, it did more so in

Practical application of these methods in museum andthe bag containing usuyoshi paper. Fabriano, Filter andlibrary spaces are the next steps for this research.

Kozosamples

showedevengreater

Method”

waspresented

asanadsorption

capabilities.

“Care and Preservation of Collections”. In: Running a Museum: A
Practical Handbook, Michalsky, S., ICOM – International Council ofMuseums (publ.), p.52, 2004
2 "「Climate Controls in a Historic House Museum in the Tropics: A
Case Study of Collection Care and Human Comfort」, Maekawa S. In
International Preservation News 54, pp. 11-16, 20113
「Tools for consevation: Monitoring for Gaseous Pollutants in Museum
Environments」, Grzywacz, C.M., California:Getty Publications, p.109,
2006
4「Key Airborne Pollutants」 Tétreault, J. In: Airborne Pollutants inMuseums, Galleries, and Archives: Risk Assessment, Control Strategies,and Preservation Management. p. 8, 2003
1

Desorption was only tested with kozo and fabriano, andno more than 1 ppm was desorbed.
This means that after paper adsorbs ammonia gas, it does
not easilt desorb it. Damaged kozo and fabriano samples
had much higher and faster adsorption rates than newones. This means that a cultural object containing papermaterial can adsorb more ammonia than new papermaterial.
Overall, the effectiveness of the “Gasbag-GastubeMethod” was proven, as was the capability of papermaterial of adsorbing gaseous pollutants without
desorbing them.

「Volatile organic compounds from wood and their influences on
museum artifact materials I. Differences in wood species and analyses of
causal substances of deterioration」Oikawa T. et al. In: Journal of Wood
Science 52 pp 363-369, 2005
6
「Indoor air quality: solutions and strategies」, (Hays et al, New York:
McGraw-Hill, 1995
5

Summaries of Academic Theses 2013