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Abstract Two multidisciplinary field surveys, one in winter and the other in summer, have monitored the indoor microclimate, the air pollution, the deposition and origin of the suspended particulate matter and the microorganisms of the Kunsthistorisches Museum, Vienna. These surveys were part of a European project aimed at identifying potential environmental risks for conservation in museums. Experimental methodologies were refined within this study. The project underscores pros and cons of the heating ventilating and air conditioning system, proposing a more effective filtration, since the system seemed to worsen indoor pollution. The impact of mass tourism during a special exhibition was investigated, showing that even a good ventilation is unable to deal with the heat and moisture released by huge crowds. The sources of gaseous and particulate pollution were discussed. Microbiological investigations identified a considerable load of bacteria. The cleaning of paintings by brush is shown to resuspend a considerable amount of particles, which are free to deposit again on the paintings.
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JOURNAL OF TRACE AND MICROPROBE TECHNIQUES
Vol. 21, No. 2, pp. 273–294, 2003
ARCHAEOLOGY AND WORKS OF ART
Multidisciplinary Environmental Monitoring
at the Kunsthistorisches Museum, Vienna
Giovanni Sturaro,
1,
*Dario Camuffo,
1
Peter Brimblecombe,
2
Rene
´Van Grieken,
3
Hans-Ju
¨rgen Busse,
4,5
Adriana Bernardi,
1
Antonio Valentino,
1
Nigel Blades,
6
Kristin Gysels,
3
Felix Deutsch,
3
Monika Wieser,
5
and Sandra Buczolits
5
1
National Research Council, Institute for Atmospheric Sciences and
Climate, Climate and Microclimate Unit, Padova, Italy
2
School of Environmental Sciences,
University of East Anglia, Norwich, UK
3
Micro & Trace Analysis Centre, University of Antwerp,
Antwerp, Belgium
4
Institut fu
¨r Bakteriologie Mykologie und Hygiene,
Veterina
¨rmedizinsche Universita
¨t, Vienna, Austria
5
Institut fu
¨r Mikrobiologie und Genetik,
Universita
¨t Wien, Vienna, Austria
6
The UCL Centre for Sustainable Heritage, Bartlett School of
Graduate Studies (Torrington Place Site),
University College London, London, UK
ABSTRACT
Two multidisciplinary field surveys, one in winter and the other in summer,
have monitored the indoor microclimate, the air pollution, the deposition and
origin of the suspended particulate matter and the microorganisms of the
*Correspondence: Giovanni Sturaro, National Research Council, Institute for Atmospheric
Sciences and Climate, Climate and Microclimate Unit, Corso Stati Uniti 4, 35127 Padova,
Italy; E-mail: g.sturaro@icis.cnr.it.
273
DOI: 10.1081/TMA-120020262 0733-4680 (Print); 1532-2270 (Online)
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Kunsthistorisches Museum, Vienna. These surveys were part of a European pro-
ject aimed at identifying potential environmental risks for conservation in
museums. Experimental methodologies were refined within this study. The project
underscores pros and cons of the heating ventilating and air conditioning system,
proposing a more effective filtration, since the system seemed to worsen indoor
pollution. The impact of mass tourism during a special exhibition was investi-
gated, showing that even a good ventilation is unable to deal with the heat and
moisture released by huge crowds. The sources of gaseous and particulate pollu-
tion were discussed. Microbiological investigations identified a considerable load
of bacteria. The cleaning of paintings by brush is shown to resuspend a consider-
able amount of particles, which are free to deposit again on the paintings.
Key Words: Indoor air quality; Museum environment; Microclimate; Air
pollution; Microbiological contamination; Mass tourism.
INTRODUCTION
Manifold are the contributions given by the various scientific disciplines to
conservation science. Causes of artwork damage and decay have been identified
and discussed and museum conservators can now base their decisions about
museum management on this knowledge. The scientific community working in this
field is now facing the next challenge, i.e., to study the linkages between the various
decay factors.
The European multidisciplinary project, called AER (Assessment of
Environmental Risk Related to Unsound Use of Technologies and Mass
Tourism), was aimed at identifying the environmental risk factors related to an
unsound use of technologies (e.g., heating, ventilating and air conditioning
systems—HVACs), to mass tourism and to inappropriate environmental manage-
ment (e.g., use of noxious substances). The basic approach was to look at micro-
climate, gaseous pollution, physico-chemical properties of particles, microbiological
contamination. The research project refined methodologies for field surveys and
subsequent laboratory tests to detect the environmental risks for the works of art.
AER main objective was to stress the importance of a multidisciplinary approach in
dealing with artwork conservation. For this reason it relied on common surveys in
the museum studied and group discussion during the periodic meeting to share the
results of the surveys. Even if the links between the various disciplines involved could
have been further exploited, the project stressed the need for contemporaneous
presence of the various experts in different disciplines for a through assessment of
the environmental risks in museums.
Four museums were studied within the AER project
[1]
: the Correr Museum
(MCV) in Venice, I
[2]
; the Sainsbury Centre for Visual Arts (SCVA) in Norwich,
UK
[3]
; the Koninklijk Museum voor Schone Kunsten (KMSK) in Antwerp, B
[4]
; the
Kunsthistorisches Museum (KHM) in Vienna, A, for which the results are presented
here. KHM is an enormous historical building, erected for this purpose in the years
1871–1891 by Gottfried Semper and Karl Hasenauer, as part of the development of
the Ringstrasse. Following the ideas of the 19th century historicism, the Renaissance
274 Sturaro et al.
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style was chosen for the exterior and the interior design of the palatial building
(Fig. 1). According to the Emperor style of that time the building was a synthesis
of architecture, pictorial and plastic decoration. It has thick walls, big exposition
rooms with tall ceiling, two internal courtyards and a wide central honour staircase
which allows air exchanges between the two floors.
The museum, like the other museums studied within the project, had conserva-
tion standards that were good compared with the average quality of other European
collections. The good standards allowed the team to concentrate on those risks,
which are less evident and for this reason less discussed in the literature, in order
to assist the Museum staff in further improving the conservation standards.
METHODS FOR MULTIDISCIPLINARY
ENVIRONMENTAL MONITORING
Multidisciplinary field tests were carried out with a synergy between the teams.
The key periods for the common surveys were the middle of the summer when the
solar forcing is at a maximum and air conditioning systems are in use at maximum
power, and the middle of the winter when the heating system determines a new arti-
ficial situation. The campaigns were carried out in Bruegel (Room X), Rubens (Room
XIII) and Mannerism (Room XXVII) rooms. Bruegel and Rubens rooms, where oil
paintings are displayed, are both in the 1st floor (Picture Gallery) and are quite similar.
They are equipped with heating, ventilating and air-conditioning (HVAC) units
Figure 1. Rubens room (XIII) in the painting gallery (first floor). The HVAC equipment is
hidden behind couches.
Environmental Monitoring at Kunsthistorisches Museum, Vienna 275
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placed in the middle of the room and hidden by couches (Fig. 1); only one side is an
external wall and there are no windows; the walls are covered with tissue tapestry. The
Mannerism room is on the ground floor (Collection of Sculptures and Decorative
Arts) and is equipped only with a heating system with radiators under the six windows,
no humidification is present. In the room bronze and stone sculptures and metal
objects of the Italian Mannerism are displayed.
The experimental methods were chosen and refined according with the project
objectives of identifying potential risks for conservation. For this reason a justifica-
tion of the choice of method is here presented together with each description of the
experimental apparatus.
Microclimate
Indoor microclimate is often monitored with a thermohygrograph placed in a
corner of a room, limiting the knowledge to only one spatial point where the instru-
ment was placed. In recent decades, the scientific interest for a more detailed analysis
of indoor microclimate has considerably increased, recognising its importance in
assessing many deterioration processes of different nature, i.e., physical, chemical
and biological (e.g.,
[5–8]
).
At KHM, the main thermo-hygrometric parameters, i.e., air temperature (T),
relative humidity (RH), specific humidity (SH) and dew point (DP) were automati-
cally measured every 15 min with thermistors (accuracy of 0.1C) and with capacitive
sensors (accuracy of 2% RH). The sensors were placed at different heights in order
to get detailed monitoring of atmospheric stability and time trends. The external air
was monitored at the level of the first floor in the internal courtyard, to compare
outdoor and indoor variations.
The space distribution of these parameters was also observed every three hours
on a horizontal plane at 1.5 m above the floor in order to obtain detailed micro
mapping of T and humidity in the room and to evidence the risk areas. A risk area is
defined as a part of the room where T and RH fluctuations are not sustainable by
artworks (e.g., for wood see
[9]
). The micromapping was based on a grid composed
approximately of 40 sampling points. Observations were taken manually by moving
the same fast psychrometer from each grid point to the next. This method detects
space patterns, horizontal gradients and time changes as extensively discussed else-
where.
[2,8,10,11]
The use of the same instruments avoids errors that may arise from the
intercomparison of different sensors which might have slightly different responses or
calibration. The psychrometer used is an electronic prototype developed by CNR
and built by Tecno.El with thermistors (accuracy 0.1C) having a response time of a
few seconds.
Gaseous Pollutants
This part of the project was concerned with the effects and occurrence of three of
the most important of the gaseous pollutants: sulfur dioxide (SO
2
), nitrogen dioxide
(NO
2
) and hydrogen sulfide (H
2
S). Regrettably, equipment failures occurred in the
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analysis of SO
2
at KHM, resulting in the loss of these data and limiting the study to
NO
2
and H
2
S.
NO
2
can cause fading in dyes and colorants, for instance in textiles.
[12]
It may
also attack textile fibres.
[13]
Whilst such effects can be readily demonstrated in the
laboratory, (e.g.,
[12,14]
) there are rather fewer accounts of actual damage occurring in
museums, which suggests that this pollutant may be less important than the other
gases in this study. Nonetheless, it is sensible to take account of its potential effects
on objects. The principal sources of NO
2
are today related to traffic, mostly in towns
and cities.
The corrosive effects of H
2
S were also recognised quite early on, in the 19th
century, if not before. The main material damage caused by H
2
S is the tarnishing of
metals (e.g.,
[15,16]
) occurring even at the very low background concentrations (<1 ppb).
Unlike SO
2
or NO
2
,H
2
S, although acutely toxic, is not a risk to public health at the
concentrations found in the ambient environment, and has not been extensively
studied. Whilst it has anthropogenic sources such as industrial emissions, it also
has a wider range of natural sources, than the other pollutants; these include vegeta-
tion, wetlands, geothermal systems and volcanic activity. H
2
S can be emitted from
the construction materials used in showcases, and will also occur as a bioeffluent.
Long term average concentrations of gaseous pollutants in museum air are
conveniently determined through the use of diffusion tubes which integrate the con-
centration over the length of the exposure time (1–4 weeks). This means that they
collect data as time weighted-averages, rather than peak readings giving a more
realistic indication of the likely exposure of museum objects. Because of their ease
of construction and cheapness, many tubes can be deployed simultaneously,
throughout a building. Hence it is possible to map the distribution of a pollutant
inside and outside a building, to gain information on how well it is excluded; which
locations may have their own sources, etc. The diffusion sampler used in this project
comprises a plastic tube with internal diameter 1.1 cm, and length 7.1 cm. During
sampling, one end of the tube is open to the atmosphere. The other end is fitted with
a cap containing two stainless steel meshes, coated with an absorbing compound
appropriate for the pollutant of interest. Polluted air diffuses down the tube, and the
pollutant reacts with the trapping agent to form an in volatile compound, which is
retained on the meshes, and can be analysed on retrieval of the tube. The amount of
pollutant collected is related to the average concentration it was exposed to by Fick’s
Law of diffusion.
The analytical methodologies used to determine the pollutants concentrations
are described in detail elsewhere (NO
2
:
[17]
;H
2
S:
[18,19]
).
Suspended Particulate Matter
Soiling of paintings and art objects occurs because of deposition of airborne
particles. The suspended particulate matter is often studied by sampling air with a
pump and collecting the large particles on a filter; the matter deposited is then
dissolved and analysed. This method has a major drawback: the coarse particles,
which may be few in number, as a proportion of the particles deposited on a surface,
will determine the character of the bulk sample chemical analysis, whereas the fine
Environmental Monitoring at Kunsthistorisches Museum, Vienna 277
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particles, which may be much more important in terms of total surface coverage,
appear as negligible traces. For this reason, bulk chemical analysis is not the pre-
ferred technique, but with automated electron probe microanalysis (EPMA) a single
particle analysis technique was chosen. The University of Antwerp group possesses
some EPMA-units, which have been highly automated for single particle analysis
and equipped with special software and hardware for imaging of elemental distribu-
tions in microscopic samples. This method allows one to analyse more than 2000
particles per day, so that in a few weeks a very large number of particles is analysed.
Subsequently, they are classified according to their size and their elemental composi-
tion, so that it is easy to recognise their origin and their potential aggressivity.
[20]
The EPMA data were processed by Hierarchical Cluster Analysis (HCA), pro-
ducing a classification into groups of particles with a similar chemical composi-
tion.
[21]
In this way, the particle types present in the museum environment can be
identified, along with their relative abundances. Information about the absolute
elemental concentrations of the indoor particulate matter could be obtained from
the EDXRF (Energy Dispersive X-ray Fluorescence) analysis of the bulk aerosol
samples. They were collected overnight on Nuclepore filters without size-segregation.
Also dry deposition samples were collected by leaving Nuclepore filters attached to
the museum walls for a period of 6–9 months. A more detailed description of these
sampling and analysis techniques is given in.
[22]
Outdoor sampling took place in one of the windows overlooking the courtyard,
where construction work was carried out during both sampling campaigns. In
addition, in winter, a new elevator was being constructed in the wing of the
museum where the indoor samples were collected.
The size of the suspended particles, a fundamental parameter to predict the fate
of the particles and the mechanisms involved in their deposition, was determined
with an optical instrument (Passive Cavity Aerosol Spectrometer Probe), as already
performed in other museums.
[2,11]
To quantify the absolute levels of particulates in the atmosphere electret dust
samplers were employed. These samplers rely on the diffusion of particulate matter
into a passive sampling device, approximately 3 cm in diameter and 1 cm deep,
where the particles are retained by an electrically charged surface. The amount of
particulate matter collected over a few days can then be determined by weighing.
[23]
Microbiological Investigations
Microorganisms are well known for their potential in biodecay of works of art.
Due to the limited access to samples, knowledge about the abundance of microor-
ganisms in the air and their biochemical properties can serve as an indirect measure
for the microbiological load to the works of art. This information may lead to the
decision whether the microclimate should be changed in order to suppress microbial
growth.
The microbiological load was analysed as described in Ref.
[3]
Microbial counts
were determined after growth on different media, including Casein MM agar,
[24]
Biotest Total Count agar and Biotest Yeast Mould Agar, from different volumes of air
(500 L and 100 L). For control also outdoor measurements were done. For detection
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of colony forming units (cfu), agar stripes were incubated at room temperature for at
least four days. Their capability for degradation of casein and Tween 80 was inves-
tigated to determine their potential for destruction of works of art which contains
proteins and/or oil. Casein hydrolysis was analysed on casein agar (5% skim milk
powder, 15% agar agar). Hydrolysis of Tween 80 was analysed as described
elsewhere.
[25]
RESULTS AND DISCUSSION
The above experimental apparatus and methods allowed the identification of
several risks for conservation; the main ones are discussed in the following sections:
(a) HVAC management; (b) mass tourism; (c) sources of pollutants; (d) microbio-
logical load; (e) cleaning activities by brush.
HVAC Management
The thermal inertia of the thick walls of this historical building helped to reduce
the fluctuations in Tand RH indoor and to establish a microclimate naturally
suitable for conservation. The HVAC system operating on the 1st floor did not
disturb this reasonably stable microclimate. The outdoor daily temperature cycle
spanned more than 10C, while indoor it was reduced to 2C in summer (average
T
i
¼25.5C, where T
i
refers to indoor T) and 1C in winter (average T
i
¼19.0C).
Similar ranges were observed on the ground floor, with a higher T
i
in summer
(27.5C) due to the absence of air conditioning. A comparison of the T
i
between
closing and opening days evidences the combined effect of visitors and museum
management: a smaller daily variability of 0.5C was measured during closing
days (Fig. 2 for the summer survey). The moisture content of the air (expressed in
terms of SH) on the first floor was found more sensitive to the presence of people and
to the operation of the HVAC than to external meteorological forcing. Indoor RH
oscillated very little in summer, and only during the closing day a greater variation
(5%) was measured, probably because the air conditioning system worked at a lower
power. Similar fluctuations in the range 55–60% RH were observed in winter. By
contrast, on the ground floor where no humidification was present, RH was much
lower and ranged between 30 and 40% (at 3 m above the floor). In summer,
perturbations occurred when windows were occasionally opened (sudden RH
variations of 10%).
The horizontal distributions of Tshowed a pattern with cool (in summer, Fig. 3)
or hot (in winter) areas in proximity of the HVAC outlets in the middle of the rooms.
The variations that occurred near the outlets, when the system was switched on or
off, did not affect the paintings on the walls: the distance was enough to smooth out
almost all the fluctuations. The same was true for the variations in the humidifying
regime, either due to moisture supply or absorption (for the response of paintings on
canvas or panels to changes in RH see e.g.,
[9,26]
). Thus, the HVAC outlets resulted
appropriately located.
Environmental Monitoring at Kunsthistorisches Museum, Vienna 279
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HVAC unbalances were observed between adjacent rooms, so that air with
different Tand RH travelled through the doors conflicting with the HVAC manage-
ment. The air inflow is visible in Fig. 3, as a cold area in Bruegel room near the door
in communication with the adjacent colder room. More complete surveys were
Figure 2. Vertical profile of the indoor air temperature at two levels (0.1 and 4 m) in the
Bruegel room during the summer survey. Notice the lower Trange when the Museum was
closed.
Figure 3. Horizontal cross-section of the air temperature, relative and specific humidity
distributions in the Bruegel room, 25 August 1997 at 14:30 h.
280 Sturaro et al.
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performed with spot observations in every room of the 1st floor, following the
curators daily practice. During the summer, T
i
on the first floor ranged from 22 to
28C. The discontinuities between rooms always showed the same pattern: warmer
near the coffee-shop area, colder in the smaller rooms, where the volume of air to
treat was much less, and the HVAC lowered too much the air temperature. The RH
pattern was chiefly determined by the temperature distribution. During the winter, T
i
ranged from 17 to 22C. RH values, apart from the coffee area where the humidifiers
were not present, ranged generally from 45% to 60%. Some rooms, where the
heaters had a lower power, remained always cooler around 17C. The higher tem-
peratures were found in the afternoon in the rooms which temporarily held a special
exhibition (Fig. 4). On the whole, it looks like the HVAC unbalances might be
corrected with a more accurate control of the heat and moisture emission, taking
into better consideration, per each room, the volume of the air to be treated.
Other weaknesses of the HVAC system were connected with the transport of
gaseous pollutants and particles. The galleries on the ground floor had lower NO
2
-
levels (18.0–20.0 ppb in winter and 21.0–23.1 ppb in summer; Table 1) than the air-
conditioned paintings galleries on the first floor (22.7–24.9 ppb in winter and
30.1–30.7 in summer). It is quite unusual to find such discrepancies within a building
(e.g.,
[2]
). It seems in this instance that the higher ventilation rate resulting from the
air-conditioning system, which lacks chemical filtration, may serve to transport NO
2
in fresh outside air to these galleries, resulting is a significantly higher concentration
than the naturally ventilated galleries.
During the winter survey refurnishing of the museum for the construction of a
new elevator was observed to disperse in the air a large quantity of particles.
Concentrations of total suspended particulate collected overnight were lower
during the weekend (Saturday 7-2-98 and Sunday 8-2-98), when there were many
visitors, than the two following days, with ongoing construction works.
Figure 4. Horizontal cross-section of air temperature in the first floor, 6 February 1998 at
16:30 h. The room number at the temperature are given for each room. In rooms VIII, IX, X,
14 and 15 the Bruegel special exhibition was held.
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Table 1. Summary of pollution measurements at the Kunsthistorisches Museum, Vienna.
Location
Winter NO
2
(ppb)
Summer NO
2
(ppb)
Winter H
2
S
(ppt)
Summer H
2
S
(ppt)
Winter
dust (10
9
mg/s cm
2
)
Summer dust
(10
9
mg/s cm
2
)
Gnd. floor (range) 18.0–20.0 21.0–23.1 6–29 50–161 1.2 2.1
1st floor (range) 22.7–24.9 30.1–30.7 11–108 83–139 0.8–5.1 1.8–3.7
Indoor (average) 21.4 26.4 39 100 2.2 2.4
Outdoor (range) 31.2–36.5 37.5–44.8 129–182 26–261 21.5 14.2
Outdoor (average) 33.8 41.1 155 143 21.5 14.2
Indoor/outdoor ratio (average) 63% 64% 25% 70% 10% 17%
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Construction works can generate many particles, especially Ca-rich (limestone) and
Ca–Si (cement and concrete) particles. These particles served as ‘tracer’ to study how
the particulate matter entered in the museum air, by comparison of the indoor and
outdoor aerosol composition. In the largest size range (>1 mm), all particle types
identified indoors, were also encountered in the outdoor samples, in comparable
abundances (Tables 2 and 3). This indicates that there are no significant indoor
aerosol sources, and that in this size range, the outdoor influence is large. In the
smallest size range (0.5–1 mm) however, the indoor and outdoor aerosol composi-
tions did not match. For instance, the S-rich and K–S-rich particles (combustion or
biological aerosols) were not encountered in the indoor samples. As air exchange is
most efficient for small particles, because of their high mobility and low deposition
velocity, this indicates that the direct exchange with the outdoor environment is very
small. Other mechanisms might be responsible for the intrusion of large outdoor
particles in the indoor environment. They could be brought in by visitors and later
resuspended or they could enter the 1st floor through the ventilation system. In
winter, the indoor and outdoor correspondence is even better due to the elevator
construction, which released even more particles (Fig. 5). Dry deposition samplers
show that the concentration of the particle types found outdoor appears to be much
lower on the naturally ventilated ground floor than on the air-conditioned first floor.
Table 2. The main particle types identified by HCA in the winter samples.
Size range
Major particle types (>10% relative abundance)
Indoor Outdoor
0.5–1 mm Ca-rich (27%) CaSO
4
(22%)
Ca–Si (22) S-rich (20%)
CaSO
4
(12) Ca-rich (12%)
Aluminosilicates (11%) K–S-rich (10%)
1–2 mm Ca-rich (29%) Ca-rich (26%)
NaCl (21%) Ca–Si (14%)
Ca–Si (11%) CaSO
4
(12%)
Aluminosilicates (11%) Aluminosilicates (12%)
Fe-rich (12%)
2–4 mm Ca-rich (34%) Ca-rich (29%)
Ca–Si (24%) Ca–Si (15%)
Aluminosilicates (14%) Aluminosilicates (13%)
4–8 mm Ca-rich (30%) Ca-rich (29%)
Ca–Si (22%) Ca–Si (20%)
Aluminosilicates (19%) Aluminosilicates (14%)
8–20 mm Ca-rich (28%) Ca-rich (37%)
Aluminosilicates (19%) Ca–Si (16%)
Ca–Si (15%) Aluminosilicates (14%)
>2 0 mm Organic-low Z (56%) Ca–Si (28%)
Si-rich (14%) Ca-rich (23%)
Aluminosilicates (12%)
Si-rich (11%)
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This supports, in agreement with the above findings, the hypothesis that the
indoor particles identified on the first floor enter the museum through the air-
conditioning system, instead of via direct air exchange. Of course, not all
outdoor particles are transported inside the museum. In fact electret dust samplers
showed that the absolute levels of particulate in the indoor atmosphere in winter
were ten times lower than outside and the summer indoor/outdoor ratio was at 0.17
(Table 1).
By contrast with gaseous and particulate pollution, HVAC on the first floor does
not increase bacterial counts, which are higher on the ground floor, as explained in
more detail in the microbiological section below.
Mass Tourism
KHM attracts a considerable number of visitors throughout the year, and espe-
cially during the holiday seasons, when tourists visit Vienna. Nevertheless the
museum has many rooms and only once in a while crowds fill the gallery. Such an
event occurred during the winter campaign when some rooms of the Picture Gallery
were dedicated to the special exhibition of the painters of the Bruegel family, with
masterpieces coming from famous collections and museums. During the Bruegel
exhibition, the central system was not able to compensate for the temperature and
Table 3. The main particle types identified by HCA in the summer samples.
Size range
Major particle types (>10% relative abundance)
Indoor Outdoor
0.5–1 mm Ca-rich (24.4%) K–S-rich (39%)
Aluminosilicates (19%) S-rich (36%)
Fe-rich (18%)
1–2 mm Ca-rich (29%) Ca-rich (22%)
Aluminosilicates (21%) Aluminosilicates (19%)
Fe-rich (15%) Fe-rich (19%)
2–4 mm Ca-rich (29%) Ca-rich (26%)
Aluminosilicates (23%) Aluminosilicates (24%)
Ca–Si (15%) Ca–Si (18%)
4–8 mm Aluminosilicates (26%) Ca-rich (30%)
Ca-rich (17%) Aluminosilicates (27%)
Ca–Si (16%) Ca–Si (20%)
8–20 mm Aluminosilicates (23%) Ca-rich (36%)
Ca-rich (21%) Aluminosilicates (27%)
Ca–Si (19%) Ca–Si (20%)
K–Cl (10%)
>20 mm Si-rich (21%) Si-rich (26%)
K–Cl (17%) Ca-rich (20%)
Ca–Si (15%) Aluminosilicates (19%)
Ca-rich (12%) Ca–Si (14%)
284 Sturaro et al.
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humidity increase due to the large number of people. When visitors were present T
i
generally increased from 19Cto24
C. The special exhibition rooms, in the after-
noons, had the highest temperature of the whole gallery (Fig. 4). The expected drop
in RH was compensated by the moisture released both by people and by the humi-
difying system (SH increase of 3 g kg
1
), and the result was a RH that remained
within the interval 55–65% but with continuous fluctuations (Fig. 6). These effects
pose a question whether the number of visitors during special exhibitions should be
limited according to the power of the HVAC plant.
People can also be considered a source of pollution. For example, the NaCl
particles found in the indoor samples collected during the winter campaign can be
Figure 5. Comparison of the indoor and outdoor relative abundances (averaged over all size
ranges) of Ca-rich, Ca–Si and CaSO particles, for the winter and summer sampling campaigns.
Environmental Monitoring at Kunsthistorisches Museum, Vienna 285
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attributed to salt used to defrost the roads. These particles had a much higher indoor
abundance, so they were probably brought in by visitors, and resuspended later.
Also bioeffluents were measured in their contribution to H
2
S concentration.
However, H
2
S in the special exhibition was lower than in other rooms: a value of
54 ppt was measured, half that of Room XI. Thus, other internal sources played a
greater role than visitors, in polluting the environment with H
2
S.
Sources of Pollutants
It was apparent from the measurements, that the only significant sources of NO
2
were external ones. This gas infiltrated the museum interior and distributed
itself homogeneously within each floor. At KHM the internal ranges were
somewhat higher (Table 1), than in the other museums of the project, i.e., MCV
and SCVA.
The NO
2
indoor/outdoor average ratio 0.64 (I/O) in the KHM was similar to the
values measured in the MCV and SCVA. It has been shown that a museum with a
large reactive surface area of walls, floors, etc in relation to its interior volume can be
more effective at removing atmospheric pollutants by process of surface adsorption,
than a museum with a lesser surface to volume ratio.
[27]
From the data collected it is
apparent that the KHM, with its traditional layout of large, open-plan interlinked
galleries is not very effective in this respect, being comparable with the MCV and
slightly better than the SCVA. It is notable that the air conditioning system, without
chemical filtration at the KHM, served to heighten the NO
2
concentration in the
conditioned galleries compared with the naturally ventilated ones.
Figure 6. Temperature and relative humidity measured in the Bruegel special exhibition
during days of mass tourism. For comparison the values measured during a closing day are
also shown (16 February 1998).
286 Sturaro et al.
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H
2
S behaved in a much less predictable way. Unlike NO
2
, it showed consider-
able variation within the building. The I/O ratio was 0.70 in the winter, and only 0.25
in the summer (Table 1). Yet in both campaigns high concentrations of over 100 ppt
were found in some rooms, indicating the presence of internal sources, but it is
difficult to say specifically what these might be.
We have already underscored how the construction works during the surveys
were a significant source of particles. In both seasons, similar particle types were
detected. In all size ranges, Ca-rich, Ca–Si and aluminosilicate particles dominated
the indoor aerosol. Fe-rich, Si-rich and CaSO
4
particles could be identified as minor
particle types. The Ca-containing particles (Ca-rich, Ca–Si and CaSO
4
) originated
from the construction works and erosion of the limestone building. Unlike in MCV,
the rooms where the indoor samples were collected, did not have plastered walls, so
degradation of wall plaster did not contribute to the abundance of Ca-rich particles.
Nevertheless, from dry deposition samplers, the Ca-content was highest on the filters
positioned in Rooms 14 and 15, which unlike the other rooms had plastered walls,
which can be held responsible for this higher deposition of Ca-containing particles.
The aluminosilicates can be identified as soil dust.
In comparison with the MCV and the SCVA, the indoor abundance of poten-
tially harmful particles was rather low. S-rich particles, which can cause fading of
dyes through oxidation to H
2
SO
4
, were only present in relative abundances <10%.
The absolute S-concentration was also low in comparison with other indoor
environments.
Microbiological Load
In agreement with the results from previous campaigns at MCV and SCVA
[2,3]
at both campaigns in the KHM, higher counts of bacteria were obtained on
caseinMM agar than on the Biotest total count agar. If not stated otherwise, only
bacterial counts obtained from 500 l of air collected on caseinMM medium are taken
into account for our considerations.
On both floors the bacterial counts in summer were significantly higher than in
winter (73% increase on the first floor and 130% increase on the ground floor).
In winter the counts of bacteria collected in the ground floor were 35% higher than
in first floor; in summer they were 75% higher (Table 4). In part, these differences
might be explained by the differing management in the two floors. Only in the
ground floor the windows were frequently opened. This results in direct exchange
with the air from outdoors where the bacterial load was in winter as well as in
summer significantly higher than indoors (2–5 fold higher). However, fungal
counts from corresponding measurements indicate that the frequent opening of
windows does not influence the indoor microbiological load as indicated from bac-
terial counts. Based on the hypothesis that airborne fungi and bacteria are similarly
exchanged between outdoors and indoors the bacterial counts should have been
40% (in winter) and 60% (in summer) lower than the measured values, since
outdoors the fungal load was 9 and 5 fold higher than indoors. Thus the relative
differences of fungal counts outdoors/indoors were significantly higher than counts
of bacteria from corresponding measurements. This observation strongly indicates
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Table 4. Bacteria and fungi collected during the summer and winter campaign in the Kunsthistorisches Museum, Vienna, expressed as colony
forming units (cfu).
Location
Sampling
volume Sampling medium
Room XIII
winter (cfu)
Room X
summer (cfu)
Room XXVII
winter (cfu)
Room XXVII
summer (cfu)
Indoor 100l CaseinMM agar 16 8 11 13
500l 42 73 56 129
Outdoor 100l 5 16 32 44
500l 28 199 292 264
Indoor 100l Biotest TC agar 2 24 7 26
500l 16 66 37 98
Outdoor 100l 3 12 10 13
500l 13 110 76 49
Indoor 100l Biotest yeast/mould agar 0 1 0 7
500l 3 3 2 25
Outdoor 100l 0 7 1 20
500l 0 50 18 129
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that one source of airborne bacteria was located within the room or that they
originated from visitors. Since the proportion of bacteria associated to human
beings was not significantly high as determined by fatty acid analysis (results not
shown), another source of these bacteria inside the museum can be assumed.
The higher bacterial counts indoors compared to outdoors measured in winter in
the first floor are not considered significant due to relatively low counts outdoors.
This result may be explained by a perturbation leading to low counts outdoors. This
assumption is supported by the values obtained from collection of airborne bacteria
on Biotest total count agar where the values indoors and outdoors were almost
identical (Table 4). However, the indicated direct exchange of air is a permanent
source of microbiological contamination. Since this contamination might also
include microorganisms which can be hazardous for certain exhibits it has to be
suggested to prevent the exchange of air without air filtering.
Isolates from both campaigns and floors were further investigated to obtain
knowledge about their potential for biodecay. The assessment of the potential for
biodecay to any works of art by investigation of the capability of the airborne
bacteria to hydrolyse casein (marker for protein degradation) and Tween 80
(marker for hydrolysation of oil) displayed opposite results for the two floors but
similar concerning the proportion of casein and Tween 80 hydrolysing bacteria. In
winter 51% and 36% of the bacteria collected on the first floor were able to hydro-
lyse casein and Tween 80, respectively, whereas in summer their proportion
decreased to 21% and 23%, respectively. In contrast, on the ground floor the pro-
portion of casein and Tween 80 hydrolysing bacteria in winter was only 35% and
22% but in summer it increased to 74% and 47%. These relative values demonstrate
that on the first floor in winter and summer the counts of casein or Tween 80
hydrolysing airborne bacteria were almost identical. In contrast, the counts of air-
borne bacteria collected on the ground floor, able to hydrolyse casein or Tween 80
was increased 6 and 4 fold, respectively. This increase can not be explained by the
overall increase observed in summer (see above) and may indicate that it is due to
protein and oil/fat containing sources in the museum which these bacteria use as a
source for carbon and energy. During the summer their growth might be supported
by higher Tand RH measured in room XXVII (26.5–28.5C and 45–5% RH) and
from this location they are suspended to the air in greater quantity. However, it can
not be unambiguously concluded that these bacteria originate from protein or oil
containing works of art exhibited on the ground floor of the KHM. On the other
hand, the proportion of casein and/or Tween 80 degrading bacteria collected in the
different rooms is too high to ignore their presence. Oil or protein containing works
of art should be carefully examined for bacterial contamination and signs of
biodecay.
Cleaning Activities by Brush
At the beginning of the winter campaign a cloud of dust from the construction
works, infiltrated the Rubens Room through some old ducts of the former ventilat-
ing system. This accounted for the huge number of coarse particles measured at the
beginning of the survey (Fig. 7). These coarse particles deposited during the night.
Environmental Monitoring at Kunsthistorisches Museum, Vienna 289
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In fact, the 5 and 10 mm particles, having density 1 g cm
3
, fall with a speed of 0.078
and 0.3 cm s
1
respectively, (the settling velocity increases proportionally to the
density) and in the absence of turbulence, they disappear in a short time.
[8]
On the
following day, the dust was cleaned from the paintings using brushes. It is interesting
to notice that this cleaning activity resuspended again the coarse particles in the air.
This result evidences how the brush removed only visible particles and dust, but it
was not able to remove coarse micrometric particles, which were resuspended and
ready to deposit again on the paintings. Submicronic particles were not particularly
affected.
CONCLUSIONS
The European project AER (Assessment of Environmental Risk Related to
Unsound Use of Technologies and Mass Tourism) developed methodologies to
investigate potential risks for conservation in buildings with a multidisciplinary
approach. The methods were positively applied to the KHM case, evidencing the
following results.
Thanks to the thick walls of this historical building, at KHM the HVAC system
operating in the 1st floor was able to maintain the microclimate within 2C and 5%
RH. However, the best situation (i.e., less perturbed microclimate) was found during
the closing days. The fact that the HVAC outlets are placed as far as possible from
the paintings avoids the fluctuations generated by the intermittent emission of
Figure 7. Trend of the suspended particle concentration for some selected diameters Dfrom
0.1 to 10 mm in the Rubens room (February, 1998). The arrow points the rise in suspended
particle concentration generated by brush-cleaning of paintings. The concentration of sus-
pended particle is expressed in terms of the number concentration density dN(D)/dlog D,
where Nis the integral size distribution and Dis the particle diameter.
[28]
290 Sturaro et al.
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treated air, and this is a positive management. Some unbalances between adjacent
rooms were evidenced, so that air with different Tand RH travelled through the
doors conflicting with the HVAC management. The unbalances might be corrected
with a more correct control of the heat and moisture emission, taking into better
consideration, per each room, the volume of the air to be treated. During the Bruegel
special exhibition the effect of a huge concentration of people was evident: the
central HVAC system was not able to compensate for the increase of temperature
and every day a 5C variation was measured: the number of visitors during special
exhibitions should thus be limited according to the power of the plant. An accidental
pollution episode due to a cloud of particles caused by breaking mortar during
building renovation was measured by chance. These particles were transported by
some old ducts and deposited on paintings. In this circumstance, the negative aspects
of the cleaning activity made with brushes was evidenced: the cleaning resuspended
the coarse particles which were ready to deposit again on the paintings.
The KHM is in a highly polluted urban location, with, in particular, high NO
2
concentrations. The museum air-conditioning is not fitted with chemical filtration,
and seems to increase the internal concentration slightly over what is observed in the
naturally ventilated galleries. H
2
S occurs at variable concentrations throughout
the museum, consistent with it having internal sources, rather than coming from
the external environment, alone. Dust levels inside the museum were ten times lower
than outside.
Both in winter and in summer, mainly Ca-rich, Ca–Si and aluminosilicate
particles were identified in the Kunsthistorisches Museum. These were generated
by the construction works, and by resuspension of soil dust. Direct exchange with
the outdoor environment appears to be rather small. This is indicated by the poor
correspondence between the indoor and outdoor composition of the smallest aerosol
particles (<1 mm). The large particles, mainly generated by the construction works,
probably enter the first floor galleries through the old air-conditioning shafts. During
the winter, the elevator construction constituted an extra source of Ca-rich and
Ca–Si particles, leading to ten times higher concentrations in comparison with the
summer.
The microbiological studies have evidenced a possible problem on the ground
floor through the counts of airborne bacteria which were significantly higher than
expected. The analysis performed was able to exclude that the origin of these bacteria
was limited to the penetration of external air through the windows. The results from
the measurements strongly indicate that the source of these bacteria was on the
ground floor. After having recognised this situation, it will be possible to proceed
in identifying the exact location of the source, and suppress the bacterial growth.
One possibility is to perform detailed analyses over every surface. Another is to pay
attention at the early appearance of signs of deterioration on the artworks on this
area. Studying the air for early indications of microorganisms presence has proved to
be a useful tool for the preservation of works of art. In general, microbiological
studies are performed to characterize bacterial isolates, which are deteriorating
artworks, for their deteriorative potential after the restorers have recognized clear
sign of decay. Based on their information, directed microbiological methods can be
employed to investigate whether this problem can be related to the presence of
bacteria and/or fungi and if necessary suitable means to suppress their growth
Environmental Monitoring at Kunsthistorisches Museum, Vienna 291
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can be applied. However, periodical air monitoring is a useful preventive practice to
avoid any risk and even the early appearance of damage.
This study showed how the joint efforts of multidisciplinary teams can lead to
improvements in artworks conservation also in museums with good standards.
ABBREVIATIONS
AER Acronym of project ‘‘Assessment of Environmental Risk Related to
Unsound Use of Technologies and Mass Tourism’’
DP Dew point
EDXRF Energy dispersive X-ray fluorescence
EPMA Automated electron probe microanalysis
HCA Hierarchical cluster analysis
HVAC Heating ventilating and air-conditioning
KHM Kunsthistorisches museum, Vienna (A); KMSK, Koninklijk
Museum voor Schone Kunsten, Antwerp (B); MCV, Correr
museum Venice (I); NO
2
, nitrogen dioxide; RH, relative humidity;
SCVA, sainsbury centre for visual arts, Norwich (UK); SH, specific
humidity; SO
2
, sulfur dioxide; T, temperature.
ACKNOWLEDGMENTS
Thanks are due to the Director General of the Kunsthistorisches Museum,
Dr. Hofrat Seipel. The research was supported by the European Commission,
Programme Environment and Climate, contract ENV4-CT95-088 AER.
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... Particulate matter (PM) pose different risks for books and manuscripts such as soiling and darkening of the surface [1], abrasion [2], and/or chemical degradation such as discolouring [3] or bloom of varnish [4]. Beside that particles may serve as an adsorbent of gaseous pollutants [5] or cause moistening due to their hygroscopicity [6], Particles can also be used as nutrients for microorganisms, whose biological activities can cause discolouring and decomposition [7,8]. ...
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Indoor air pollution in archives can cause irreversible degradation of materials stored there. Thus, detailed information about indoor air quality is essential before control strategies could be investigated. In a period 2008–2019, the relationship between the indoor and outdoor pollution was investigated in four naturally ventilated archives located in historical buildings and situated in regions with different outdoor air quality. The indoor and outdoor particle number, mass, and chemical size distributions were measured during different seasons. Moreover, air change rates (a), penetration coefficients (P), and deposition velocities (Vd) were determined. The results revealed that the most important source of the indoor particulate matter was the outdoor air. The size-resolved data with no indoor sources were evaluated using the steady-state solution of the mass balance equation as the I/O ratio. The results showed that all parameters (a, P, and Vd) determined in archives were comparable with low seasonal variation, probably due to the similar building characteristics. Further, the typical average values of the I/O ratio for naturally ventilated historical buildings were estimated. Finally, the long-term indoor concentrations, for periods when no measurement was in place, were determined using data from the local monitoring network. The results showed that the higher level of pollution and therefore the higher degree of degradation is expected in depositories located in highly polluted regions.
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The calculation of pollution mass balances is explained with reference to the modelling of indoor air quality in museums, and the implication of pollution deposition indoors and on museum objects is discussed. A short overview of the key pollutants in the museum environment and their effect on materials is given. Case studies, comparing old and new buildings, with and without air-filtration, in both urban and rural areas, suggest that pollution mainly infiltrates buildings via free air movement and that passive control measures may be sufficient to exclude outdoor pollutants. What this means for the level of pollutants generated indoors is not clear. Other studies have shown benefits from the use of active air-filtration, especially in urban areas with high pollution levels. The use of dosimeters rather than concentration measurements is now a focus in conservation research. Different approaches to setting acceptable limits for air pollution are briefly discussed, including the establishment of 'adverse effect levels'.
... Fine particles can penetrate into books (Smolík et al., 2013), where they may cause chemical degradation or moistening due to their hygroscopicity (Hatchfield, 2002). Particles can also serve as nutrients for microorganisms, whose biological activities can cause discolouring and decomposition (Altenburger et al., 1996;Garg et al., 1995;Pangallo et al., 2007;Sanchez-Moral et al., 2005;Sturaro et al., 2003;Urzi et al., 2001). Detailed studies of the chemical composition of size resolved PM in the indoor environment of cultural heritage buildings are scarce. ...
Article
To determine the composition of particulate matter (PM) in the indoor environments of four different types of archives (three naturally ventilated and one filtered), intensive size-resolved sampling was performed for four seasons of the year. For reconstituting indoor PM, nine aerosol components were considered. Organic matter was the dominant component of both fine and coarse fractions and represented approximately 50–80% of the PM. In the fine fraction, the next most abundant components were elemental carbon and sulphate, and in the coarse fraction the next most abundant were crustal matter, sulphate and nitrate. The resulting mass closure explained 95(±13)% and 115(±38)% of the gravimetric indoor PM in the fine and coarse size fractions, respectively. The results revealed that all the particles found indoors can be considered to be potentially threatening to the stored materials. The results also showed that the most important source of indoor PM in the naturally ventilated archives was penetration from the outdoor air, whereas in the filtered archive, the concentrations of particles were strongly reduced. In naturally ventilated archives the influence of domestic heating, road traffic and local sources (industrial pollution, camp fires) was observed. Furthermore, activities of the staff were identified as an indoor source of coarse particles in all archives.
... This research was performed in the framework of a European project that studied four museums, having different climate and pollution conditions: The Correr Museum, Venice, Italy [8]; Kunsthistorisches Museum, Vienna, Austria [9]; KMSK and Sainsbury Centre for Visual Arts, Norwich, UK [10]. The first three museums are of traditional design, housed in historic buildings; the last one has a modern design, with use of new materials (glass and metal). ...
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Indoor and outdoor atmospheres of the ‘Koninklijk Museum voor Schone Kunsten’ (KMSK, Royal Museum of Fine Arts) in Antwerp, Belgium, were thoroughly characterised to determine the air quality inside the museum and the factors controlling it. During a winter and a summer campaign aerosol particles, pollutant gases, bacteria and fungi were sampled and different indoors microclimatic parameters were measured. The chemical composition of particulates suspended in indoor and outdoor air was analysed, both with reference to bulk aerosol matter and to individual particles. Outdoor sources largely determined the composition of indoor aerosol. The main particle types identified in winter were Ca-rich, Ca–Si and sea salt particles. In summer, S-rich particles were most abundant. Dry deposition was sampled in order to determine the amount of particulate matter that could potentially deposit onto the works of art. The concentrations of NO2 and SO2 amounted to 12 and 5–6 ppb, respectively, both in winter and in the summer. The microclimates inside the exhibition rooms were affected by poorly balanced heating and air-conditioning, free-standing humidifiers, ventilating and lighting systems and the daily flux of visitors, which produced rapid changes and marked thermo-hygrometric gradients. Based on these results, suggestions for the improvement of the heating and air-conditioning system could be made. Microbial loads were higher in summer than in winter. However, the proportion of microorganisms capable of degrading proteins or hydrolysing fats, and thus pernicious to works of art, was not significantly increased inside the museum.
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Musical instruments which are part of our rich cultural heritage are unique and therefore strict rules of preservative conservation must be applied. Preservative conservation is understood as any measure that prevents damage or reduces the potential of it. Conservative preservation is characterized by three stages: revelation, investigation and preservation. In the conservation of musical instruments there is there is an increasing risk of damage introduced by the diversity of materials on which the musical instruments are built. Major degradations observed in materials used for musical instruments are: biological degradations produced by bacteria, fungi and insects; chemical reactions involving oxidation, hydrolysis reactions etc; thermal and photo degradations produced by environment light; interaction with air humidity producing cracks, corrosion, etc. We know that the violin and the harpsichord have had, and still have a leading position in Baroque musical performance. These instruments have had enormous significance in the history of music. In this chapter is analysed the mechanical behaviour of two remarkable instruments, the violin the “Cannone” made in Cremona by Guarnieri del Gesu in 1743 which has belonged to Paganini and the harpsichord made by Couchet in 1652 in Anvers. Three methods have been used, X – ray imaging, impulse near field acoustic holography and finite elements analysis. The deterioration rate of musical instruments should be substantially improved by cleaning and regular maintenance.
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The paper presents selected results from the EC 6FP "PICTURE" Project dealing with the Proactive management of the Impact of Cultural Tourism upon Urban Resources and Economies. The gathered knowledge about the impact of tourism upon built heritage is based on a scientific literature review and previous work, done by ITAM-ARCCHIP, with a focus on impacts and risks generated by large visitor numbers at sites and built objects of cultural heritage interest. This overview is accompanied by the results of some case studies from the sites which are monitored in detail, namely from the World Heritage City of Prague and Telč.
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This paper aims to assess the possible impact of air pollution on works of art kept in storage at the Museum of Modern and Contemporary Art. Soiling removed during the process of conservation-restoration was analysed for its ionic content, lead, soot and polynuclear aromatic hydrocarbons. The samples were taken from four paintings: two of them had been kept in the central store within the Museum's building since the mid-1970s or 1980s, while the other two had been stored in temporary storage in the city centre since the mid-1990s. The common characteristic of all the soiling was the predominance of sulphate and calcium. These two ions are dominant in the aerosol composition found indoors, their source being either plaster soiling and/or chemical reactions of sulphur dioxide with calcite. The excess of sulphate relative to calcium found in the two paintings kept in the central store when the outdoor air pollution was highest, suggests the air pollution impact. No excess of sulphate was found in the two paintings stored in the temporary store since the 1990s, when the outdoor air pollution of sulphur dioxide was substantionally reduced. In this case high levels of calcium were found, probably due to calcite soil and building materials.
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Indoor and outdoor atmospheres of the ‘Koninklijk Museum voor Schone Kunsten’ (KMSK, Royal Museum of Fine Arts) in Antwerp, Belgium, were thoroughly characterised to determine the air quality inside the museum and the factors controlling it. During a winter and a summer campaign aerosol particles, pollutant gases, bacteria and fungi were sampled and different indoors microclimatic parameters were measured. The chemical composition of particulates suspended in indoor and outdoor air was analysed, both with reference to bulk aerosol matter and to individual particles. Outdoor sources largely determined the composition of indoor aerosol. The main particle types identified in winter were Ca-rich, Ca–Si and sea salt particles. In summer, S-rich particles were most abundant. Dry deposition was sampled in order to determine the amount of particulate matter that could potentially deposit onto the works of art. The concentrations of NO2 and SO2 amounted to 12 and 5–6 ppb, respectively, both in winter and in the summer. The microclimates inside the exhibition rooms were affected by poorly balanced heating and air-conditioning, free-standing humidifiers, ventilating and lighting systems and the daily flux of visitors, which produced rapid changes and marked thermo-hygrometric gradients. Based on these results, suggestions for the improvement of the heating and air-conditioning system could be made. Microbial loads were higher in summer than in winter. However, the proportion of microorganisms capable of degrading proteins or hydrolysing fats, and thus pernicious to works of art, was not significantly increased inside the museum.
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To save energy and comply with the IAQ procedure in ASHRAE Standard 62-1999 or to add protection to occupants and contents in a building, more building owners and facility managers are using gas-phase filtration (GPAFE) in their buildings. However; GPAFE is fraught with questions about changeout schedules, lifetimes, and capture efficiencies, particularly during episodic events. To save money, facility managers try to minimize filter changeout and sometime eliminate the GPAFE filter banks entirely. Facility managers need to truly understand the service life and capture efficiency of GPAFE systems to effectively (both for protection and cost) use this type of filtration in buildings. To meet these needs ASHRAE initiated a research project in two phases: Field Test Methods to Measure Contaminant Removal Effectiveness of Gas Phase Air Filtration Equipment: Phase I, Search of Literature and Prior Art, 791-RP and Phase II: Field Test Methods to Measure Contaminant Removal Effectiveness of Gas Phase Air Filtration Equipment, 791-RP (1098-TRP). This paper reports on the findings of Phase II, which was charged with the development ofa field test method that would provide building managers and maintenance staff with a procedure to determine GPFAE filter removal efficiencies and lifetimes in their buildings and to provide data on the lifetime and removal efficiency of GPAFE filters in a variety of building types. The research project collected a large quantity of data from six buildings, which indicated that measuring low concentrations of individual VOCs upstream and downstream of the filter bank does not provide information that will allow a building manager to determine the optimum time for GPAFE filters changeout due to the very low levels of individual VOCs and the constantly changing environment Measuring TVOCs may yield better data, since the level of TVOCs will be at higher concentrations than any of the individual VOCs. The use of active or passive samples may provide a tool to build up a profile of the general operation of the GPAFE filters in a specific facility; this, with a combination of other data, such as odor complaints or activities, can provide a database of knowledge that will assist facility managers with predicting imminent filter exhaustion and an "action point" of when to change the GPAFE filters.
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This is a useful microphysics handbook for conservators and specialists in physics, chemistry, architecture, engineering, geology and biology dealing with the environment and works of art. A rigourous treatment and a background familiarity with the underlying physics behind mathematics are covered, giving a detailed description and interpretation of the main microphysical phenomena, removing unsound popular beliefs. The basis are given for non-destructive diagnostics to evaluate causes of damage determined by atmoshpheric factors, as well as negative consequences of the unsound use of technology and mass tourism. To this aim, suggestions are given on the fundamental principles in designing heating, air conditioning, lighting and in reducing the deposition of pollutants on works of art. Theory and experience are coupled to describe the complex condensation mechanisms and the fundamental role played by water in the stone deterioration and the formation of crusts on monuments. Urban meteorology, air-surface interactions, atmospheric stability, dispersion and deposition of airborne pollutants are also key topics of this book, for which the main aim has been to make comprehensible to a wider audience a matter that is only familiar to a few specialists. This book combines a theoretical background with many years of accurate laboratory research, field surveys and practice. The first part, devoted to applied theory, is a concise treatise on microphysics, which includes a survey on the basic ideas which are necessary for environmental diagnostic and conservation. The second part of the book focuses on the practical utilisation and shows in detail how field surveys should be performed, with many suggestions and examples and the indication of some common errors that should be avoided.
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The study of the microclimate of the Sistine Chapel, Rome, is an instructive example of several general problems, either in the methodology used for environmental testing or in the philosophy of conservation. In recent years the Sistine Chapel, as may other historical buildings, has been subject to new microclimatic conditions due to the massive flux of visitors to the monument. At the beginning cf this study, the main new risk factors were: artificial lighting, heating, airborne pollutants and release of heat and moisture by the visitors. A long and accurate study of the microclimate and deposition processes of airborne particles has been carried aut in the Sistine Chapel. Experimental surveys were carried aut in arder to measure the main environmental parameters, their gradients and rates and show the seasonal and diurnal dynamics of the microclimate and the lactors which may cause dangerous microphysical processes affecting the frescoes, i.e. deposition cf pollutants, mechanical stresses, microfractures, condensation and evaporation cycles in the micropores. Maps of observed data (thermo-hygrometric parameters on the horizontal cross section of the Chapel, atmospheric stability etc.) and theory are extensively discussed in order to point out the microphysical processes responsible far the deterioration of the monument. The trajectories of solar beams on the frescoes have been reconstructed using a computer. The conditions existing in the undisturbed environment are suitable for the conservation of the frescoes, although critical periods over the day and the calendar year were found. The main causes of the perturbations include: the presence of visitors, the heating and lighting systems and the cleaning methods. The last part of the paper is devoted to comments and suggestions about what has been made or should be done in order to reduce, as far as possible, the deterioration of the monument. After analysis of the problem, some suggestions were made (with science supporting technology and management) in order to reduce, as far as possible, changes in the natural microclimate but, at the same time, making the Chapel comfortable for visitors and allowing for the maximum exploitation of the artwork without imposing too many restrictions and without exposing the artwork to excessive risk or damage.
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The activity concentration and the size distribution of the ⁷Be in atmospheric aerosol were measured in ground-level air. Aerosol sampling was performed with a cascade impactor covering the size range from 0.49 to 7.2 μm and simultaneously with a high-volume sampler. Activity of ⁷Be was measured by gamma spectrometry. During sampling period, the concentration mean of the ⁷Be is 7.29 mBq/m³ and it is high in spring. It is found that ⁷Be almost cannot be detected on aerosols above 3.0 μm in diameter. Aerosols larger than 0.95 μm are attached by about 10% of total ⁷Be. The most ⁷Be activity is associated with aerosols smaller than 0.95 μm.
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A rapid five-step sequential leaching procedure was developed for speciation of S, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn and Pb in the certified reference material, NIST (NBS) 1648 Urban Particulate Matter applying centrifugation, stepwise tip-filtration or continuous-flow filtration to separate the leachate fractions. The element concentrations were determined by TXRF spectrometry in the range of 80 μg g-1 to 50 mg g-1, investigating 1 to 20 mg aerosol samples. The leaching time was reduced to 20 min for each step and a further reduction to l min was proved to be sufficient for extraction of the environmentally available fraction. The exchangable (water soluble) fraction of Ca, Ni, S, Zn and Cu, K, Mn, V amounted to 50 to 80% and 20 to 40%, respectively. In hydrochloric acid nearly the total amount of Pb, 70% of Cu, 30 to 40% of V, Mn, Fe, Ni and Zn were dissolved. A total recovery of 89 to 114% was found for all elements investigated with exception of K, Ti and Cr which gave a deficit from 30 to 70%.
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The silver nitrate/fluorescein mercuric acetate fluorimetric method for the measurement of atmospheric hydrogen sulfide has been adapted to passive sampling. Standard samplers have been tested and used in both indoor and outdoor environments. Sampler performance was not dependent on construction materials or sunlight intensity and gave similar results to active sampling. Two case studies were carried out, one in the Horniman Museum and its associated storage and study building, London, UK, and the other in the vicinity of a pulp and paper mill and geothermal area North Island, New Zealand. The detection limit of the samplers (50 ppt average for a one-week exposure) provides the opportunity to make measurements in a variety of locations provided exposure times are sufficiently long, i.e., up to one month in areas of low hydrogen sulfide concentration.
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Typical stratospheric aerosol size distributions so far proposed are examined on the basis of data on lidar backscattering and on small ion density. It is shown that power law distribution can account for both lidar backscattering coefficient and small ion density if Aitken particles are taken into account. Bimodal size distribution is the result of both sulfuric acid nucleation and increased outer particle injection such as meteor particles or volcanic eruption. Aerosol size distribution is calculated for meteor particles undergoing sedimentation, eddy diffusion, and growth by attachment of tiny sulfuric acid particles under the assumption of power law size distribution. Meteor particle size distribution is found to be lognormal. Bimodal size distribution is formed both by the lognormal size distribution and the preexisting Aitken size sulfuric acid particles.