An Approach to Management of Critical Indoor Air Problems in School Buildings 

Ulla Haverinen,l Tuula Human,' Mika Toivola,l Jommi Suonketo? Matti Pentti? Ralf Lindberg? Jouni Leinonen 3 Anne Hyvarinen,l Teija Meklin,l and Aino Nevalainenl 

'National Public Health Institute, Laboratory of Environmental Microbiology and Unit of Epidemiology, Kuopio, Finland ; 2Tampere 

University of Technology, Laboratory of Structural Engineering, Tampere, Finland ; 3Korpilahti Town, Korpilahti, Finland 

This study was conducted in a school center that had been the focus of intense public concern 

over 2 years because of suspected mold and health problems . Because several attempts to find 

solutions to the problem within the community were not satisfactory, outside specialists were 

needed for support in solving the problem. The study group consisted of experts in civil 

engineering, indoor mycology, and epidemiology. The studies were conducted in close 

cooperation with the city administration . Structures at risk were opened, moisture and 

temperature were measured, and the causes of damage were analyzed . Microbial samples 

were taken from the air, surfaces, and materials . Health questionnaires were sent to the 

schoolchildren and personnel . Information on the measurements and their results was released 

regularly to school employees, students and their parents, and to the media. Repairs were 

designed on the basis of this information . Moisture damage was caused mainly by difficult 

moisture conditions at the building site, poor ventilation, and water leaks . Fungal genera 

(concentrations <200 colony-forming units (cfu)/m3, <3000 cfu/cmz) typical to buildings with 

mold problems (e .g ., Aspergiqus versicolor, Eurotium) were collected from the indoor air and 

surfaces of the school buildings. Where moisture-prone structures were identified and visible 

signs of damage or elevated moisture content were recorded, the numbers of microbes also 

were high ; thus microbial results from material samples supported the conclusions made in the 

structural studies . Several irritative and recurrent symptoms were common among the upper 

secondary and high school students . The prevalence of asthma was high (13%) among the 

upper secondary school students . During the last 4 years, the incidence of asthma was 3-fold 

that of the previous 4-year period . Key words: asthma, health effects, moisture damages, mold, 

questionnaire, respiratory symptoms . - Environ Health Perspect 107(suppl 3) :509-514 (1999) . 

http://ehpnetl .niehs.nih.gov/docs/1999/suppl-3/509-514haverinen/abstract .html 

Indoor air problems caused by the moisture and mold occur not only in residential 

but also in public buildings (1) . Microbial 

growth and building moisture is associated 

with adverse health effects such as respiratory symptoms and the increased prevalence of respiratory infections (2) . In many 

cases, however, there is not sufficient local 

experience to recognize a building-associated disease, to determine the documentation needed for correct conclusions, and to 

manage the overall case . This study concerns a school center in a small town in 

southern Finland, where the occupants had 

symptoms associated with the buildings. As 

experience with indoor air problems was 

insufficient among the health authorities, 

the town administration turned to a group 

of outside experts . The aims of the study 

were to assess the moisture and microbial 

status of the school buildings and the 

health situation of the school occupants, 

and to establish a strategy to deal with this 

type of problem. 

We report an approach to managing 

indoor air problems associated with moisture and mold in a practical situation . The 

investigations and analyses required to 

obtain the necessary information, as well as 

the essential findings, are briefly described . 

Material and Methods 

The school center contained three buildings . The upper secondary and high 

schools were located mainly in building 

complex A, called stone school, which has 

three parts : part A1 (built in 1954), part 

A2 (built in 1951), and part A3 (built in 

1961). Building B, the elementary school, 

is a brick building built in 1955. In addition, the upper secondary and high schools 

use facilities from building C-the wooden 

school, a log building constructed in 1888. 

The study included structural, microbial, and health effects studies . Each part of 

the study was supervised by experts in the 

field . All studies were done in close cooperation with the town administration . The 

studies advanced hierarchically and the 

results of each step were discussed in meetings . The overall design of the study is 

presented in Figure 1 . 

$tructural Survey 

This section of the study analyzes the 

moisture status of the structures and the 

causes of the moisture accumulation . On 

the basis of the results of the investigations, 

advice was given on the removal and 

replacement of the damaged structures and 

improving the moisture capacity, i .e ., the 

resistance of the structures against moisture . The project started in June 1996, 

after the schools were closed for summer 

vacation, and the repairs were to be completed before the new semester started in 

August of the same year . Because of the 

schedule, the study was conducted parallel 

with the construction work. 

All available building documents, e .g., 

drawings, structural designs, and information about repair history of the buildings, 

were collected and the buildings were first 

examined visually (3) . The most serious 

problems were registered in the base floors 

of the buildings . For on-site investigations, 

20-mm holes were drilled throughout 

ground slab at 15 sites and through the wall 

structures at 2 sites (Figure 2) . Building 

material layers and thickness were observed 

from cuttings and drill ability . If the 

drilling was successful, the holes were 

obstructed and the conditions were allowed 

to stabilize before moisture and temperature was measured . A bar was driven into 

the holes until the resistance became too 

great, to define soil type and moisture condition . To obtain more information, the 

structures were later opened (e .g ., areas of 

approximately 0.2-1 mz were dismantled at 

10 sites) (Figure 2) . The ventilation in the 

This article is based on a presentation at the 

International Conference on Indoor Mold and Children 

held 21-24 April 1998 in Alexandria, Virginia, 

Address correspondence to U. Haverinen, National 

Public Health Institute, POB 95, FIN-70701 Kuopio, 

Finland. Telephone: 358 17 201 211. Fax: 358 17 201 

155. E-mail : ulla .haverinenCktl .fi 

The authors thank U . Kolehmainen, M. Vahteristo, 

and J . Chelelgo for their excellent technical assistance, and the students and teachers of the school 

center for cooperation during the study. The study 

was supported financially by the Finnish Ministry of 

Education. 

Received 3 September 1998 ; accepted 2 February 

1999. 

Environmental Health Perspectives " Vol 107, Supplement 3 " June 1999 509 
p. 2 

HAVERINEN ET AL. 

crawl spaces under the ground floors was 

tested with a thermohygrograph . 

Microbial Study 

Microbial samples were taken to locate the 

sources of microbial growth and to characterize the fungal genera of the buildings for 

;i1'"ri :-"'i .~ al 

Basic data 

Collect 0~ 

i 

` 

i As : essiTlent . Anaip<;es 

i d r d of of rsR 

~ ir~ r { structures 

;,3m~r ~ r:=as~ns 

mprehe : 

Qet~ : ; the principles o# repai 

---_ 

"f-- ---_ . 

J 

exposure assessment (4). Basic data from 

the microbiologic indoor air quality were 

obtained before construction started . 

Airborne samples were collected with sixstage impactors . Surface samples were collected by swabs, diluted, and plated onto 

culture medium. Material samples were 

5upervslon 

ot 

iistrtrctian 

Figure 1 . Flow chart of the study design . 

led techni(I-c 

Fc1~ .°~ L J-_ s`- .d "s, 

Figure 2 Site map of structural measures. See Table 1 . 

Part Al Basement 

Heat distribution 

OOG 

- I e© e 

i 

Teaching 

equipment 

O 

Classroom 

Teaching 

equipment 

Classroom 

Li 

taken from various layers of the moistureprone structures (such as surfaces, insulation, frames) when they were dismantled 

for structure investigations . One to five 

grams of material was used for extraction 

of the microbes, and the suspension was 

plated onto culture medium . 

Two percent malt extract and dichloranglyserol-18 agars were used for mesophilic 

fungi, and tryptone glucose yeast agar was 

used for bacteria. After 7 days of incubation 

at 25°C, the colonies were counted and the 

fungal flora was determined. The bacterial 

samples were incubated at 20°C for 14 

days . Concentrations of viable fungi were 

regarded as elevated according to the guidelines given by Finnish Ministry of Social 

Affairs and Health (S) : air samples > 100 

colony-forming units (cfu)/m3 if the finding 

was supported by the unusual genera, surface samples > 1,000 cfu/cm2, and material 

samples > 10,000 cfu/g . The fungal colonies 

were identified morphologically. The occurrence of the genera, which indicated moisture as well as an unusual rank order of the 

genera (4,6), was recorded. 

Surveyors were advised to wear respiration filters and protective clothing during 

those stages of the investigations when 

mold or dusty materials were handled. 

Problematic rooms were not used and were 

isolated before they were repaired to avoid 

air change between other facilities . Some 

repairs were performed using dust techniques similar to those used in asbestos 

abatement . Recommendations were made 

for cleaning of the rooms (working methods, chemical types, etc .) after the removal 

of materials contaminated by microbes . 

These included wiping all surfaces and disinfecting materials prone to contamination, 

e.g ., chlorine treatment of concrete (7) . In 

addition, to protect wooden parts that 

could not be replaced, disinfection with 

boron substances was recommended . 

Symptom Survey 

Questionnaires on respiratory disorders 

and other irritative and general symptoms 

were delivered to the occupants of the 

buildings before any technical investigations began. The questionnaires for the 

students were delivered by the teachers of 

each school level . The upper secondary and 

high school students filled in the questionnaires themselves (with help from their 

parents if needed) . The questionnaires of 

the elementary school students were completed by the parents together with the 

child . The students returned the questionnaires to the schools, where they were 

510 Environmental Health Perspectives " Vol 107, Supplement 3 " June 1999 
p. 3 

MANAGEMENT OF INDOOR AIR PROBLEMS IN SCHOOLS 

collected by the teacher . Questionnaires for 

school personnel were sent to their homes 

with return instructions and prepaid 

envelopes . About 1 month later, letters of 

inquiry were sent to the homes of both students and personnel who had not returned 

the questionnaire . 

The questionnaires used were developed 

on the basis of earlier studies on air pollution and respiratory health (8,9) ; they had 

been used for mold-related designs in several studies (10,11) . The questionnaire for 

students included 44 questions on respiratory and general health, and allergies of the 

subject ; 12 questions on housing and 

sociodemographics of the families ; and 16 

questions about the school. Asthma was 

included: Has a doctor ever said that you 

have/your child has asthma? (No/Yes, diagnosed year 19_.) The questionnaire for the 

employees was more specific and consisted 

of a section on working conditions with 31 

questions and a section on health information with 91 questions . In the section on 

working conditions, there were questions 

about the work, employee position and 

length of service, working motivation and 

atmosphere, and causes and sites of inconveniences experienced by the work. The 

section on health information documented 

symptoms and diseases such as respiratory 

infections and factors that were related to 

them according to the respondent . General 

information, such as housing, living habits 

(smoking, free-time activities), and education, was also recorded in this section of the 

employee questionnaire . 

The extent of symptoms of the students and personnel working in buildings 

A and C were compared with those in 

building B, which was assumed to be a 

nondamaged reference building . The data 

were analyzed with the SPSS program 

(SPSS 6 z .0 for Windows) by using x 

and >rtests, adjusting for age, sex, smoking, 

and atopy with logistic regression model 

(12) . The accepted level of statistical 

significance wasp < 0.05 . 

Risk Communication 

Because suspected indoor air problems had 

hitherto remained unsolved and caused 

public concern for over 2 years, there was 

little confidence among school personnel, 

parents, and the general public that the 

authorities would find a solution . Special 

attention was paid to communication in 

overcoming this problem . During the 

study, information about the investigations 

and the results was released to school 

employees, students and their parents, the 

general public, and the media. 

Results 

Causes and Comprehension 

of Moisture Damages 

One of the main reasons for problems in the 

wooden school (C) was poor ventilation of 

the base floor structures. During the 1970s, 

the ventilation holes had been obstructed in 

an attempt to save energy. The ground was 

graded toward the building, which directed 

the flow of rainwater under the building . 

Depart from the drawings of the buildings, 

the surface of the ground was partly level 

with the wooden frame. Some incorrect 

construction methods are used . The building lacked mechanical ventilation as well. 

These conditions led to the growth of rot 

fungi, causing decay of the base floor structures and lower wall logs, and creating a risk 

for the collapse of the floor structures (13) . 

After a fire in 1984, large areas had been 

covered with water . High concentrations of 

fungi and bacteria were found in upper 

floor insulation materials, indicating that 

some wet materials may have been left in 

the building . All contaminated materials 

were destroyed at the time of the study at 

this phase. 

Various structure layers were observed 

from different sites in the stone school (A) 

and assumed to be results of earlier repairs . 

In general, structures could be categorized 

into two types : structures with layers of 

wooden materials and structures consisting 

mainly of concrete materials (Figure 3) . 

Results from the structural measurements 

in the building are presented in Table 1 . 

Moisture conditions in the site were problematic . The base floor was built mostly on 

a thick level of capillary clay, partly without 

Structure type 1 : wooden materials 

° o 00 0 

Relative humidry, 

temperature 1 

.9- 

1 . Surface material 

2.15 mm Chipboard 

3. 21 mm Timber boarding 

4.100 mm Mineral wood r supporting beam 5.50-BOmm Secondary support 

6. Bitumen coat 

7 . >120 mm Ground slab 

+ temperature 2 

h meter below layer 1) 

Structure type 2 : concrete 

----°r -9- 

Relative humidity, 

temperature 1 

0 1) o 

1 . Surface material (plastic mat etc .l 2.68-80 Reinforced surface slab 3. Double plastic sheet 

4. Leveling course 

5 . Bitumen coat 

6 .50 mm Concrete slab 

7 . Bitumen coat 8 . >300 mm Ground slab + temperature 2 

(1 meter below layer 1) 

Figure 3. Examples of base floor structures in the 

stone school (A), categorized as wooden structures 

(type 1) and concrete structures (type 2). See Table 1 . 

Table 1 . Results of the structural measures . 

Drill hole Structure Relative 

number opening number humidity (%) 

Room Temperature 1 a Temperature 2a 

temperature (°C) (°C) (1C 

Type of the Microbial Microbial 

structures sample taken growth recorded 

1 - 

1 - 90 

2 2 90 

3 - 88 

4 3 d 

5 4 88 

6 5 80 

6 - 20 

7 - 93 

8 - 94 

- 54 

10 - 94 

19 - _ 

19 17 16° 

19 15 - 

19 20 -

19 - -

- - 1 

20 16 13e 

20 19 17r 

20 18 14r 

20 19 16c 

2 Yes Yesb 

2 Yes No 

1 Yes No 

1 Yes No 

1 Yes Yes 

2 No -

2 Yes No 

Yes Yes 

1 No -

2 No -

2 No -

2 No - 

'According 

around slab

to 

. 

Figure 3 . 'Microbial growth recorded under the topping slab . °Water does not flow below the ground slab aWood sample moisture content 12% by weight . 'Water flows below the 

Environmental Health Perspectives " Vol 107, Supplement 3 " June 1999 S11 
HAVERINEN ET AL. 

capillary break. A groundwater monitoring 

tube showed that the groundwater was at 

the level of the concrete slab lower surface . 

Before the underdrain, rainwater sewer, and 

cellar walls outside the water barrier were 

built in the fall of 1995 as part of the repair 

process, surface water could seep under the 

building . Changes in this type of soil occur 

slowly, but it may also be impossible to 

stop the water penetration. All wooden 

structures (structure type 1) of the floor of 

the basement store had to be replaced by 

structures with better moisture resistance 

(14) and with surfaces through which 

possible moisture would evaporate . 

In the elementary school (B) basement 

classroom, damaged floor structures were 

observed . Although the measurements did 

not indicate unusual moisture, the structure was opened. Under the chipboard 

layer an area of approximately 1 square 

meter was filled with water from a leak in 

the plumbing. 

Microbial Status 

in the wooden school (C), rot fungi damages 

were obvious, as assessed by the deterioration 

of wooden structures . Airborne concentrations of viable fungi in the stone and elementary schools were at the level normally 

found in school buildings (15) . However, 

small concentrations of fungal genera typical 

to buildings with mold problems (Aspergzllus 

versicolor, Aspergillus fumigatus, Eurotium) 

were found in the stone school's (A) air 

samples (6) . (Data not shown.) 

In some surface samples of the stone 

school (A), concentrations were unusually 

high, and the genera present, e .g. A. versicolor, indicated problems with moisture 

and mold (6) . A. versicolar, which is often 

associated with damp buildings, was the 

most common genus detected in various 

damaged samples. The concentrations of 

A. versicolor are therefore presented here as 

an example (Table 2) . 

In general, microbial results from material 

samples supported the conclusions made in 

the structural studies (Table 3) . For example, high concentrations of fungi detected 

from the materials from wooden floor 

structures of the stone school (A) (sample 

1) indicated a high moisture content and 

the decision was made to remove the structures. Microbial concentrations in the concrete floor structures were relatively small 

(sample 2) . Sample 3 from the classroom 

in the elementary school (B) had high concentrations of fungi . In addition to rot 

fungi, mold was also found in the wooden 

school (C structures (sample 4) . 

Table 2 Occurrence of Aspergillus versicolor in various samples taken from school buildings. 

Concentration of A. versicolor 

in risk facilities and structures 

Building A 

Indoor air samples 0-180 cfu /m3 

Surface samples 0-2,230 cfu/cmz 

Material samples 0-10,500 cfu/g 

Building B 

Indoor air samples -

Surface samples -

Material samples -

Building C 

Indoor air samples 0-10 cfu/m3 

Material samples 0-222,000 cfu/g 

Concentration of A. versicolor 

in reference samples 

Outdoor air 

Reference surfaces 

Outdoor air 

Reference surfaces 

Outdoor air 

Table 3. Concentrations of viable fungi on building materials from some risk structures . 

Samples Total fungi range (cfu/g) Total bacteria range (cfu/g) 

1-Building A, base floor, wooden structures (type 1) 

2-Building A, base floor, concrete structures (type 2) 

3-Building B, classroom base floor, chipboard 

4-Building C, floor and lower wall log structures 

50-11,400 270-2,160 

0-150 0-950 

772,000 585,000 

0-527,000 1B0-830,000 

Health FHects 

The completed questionnaire was returned 

by 171 (81%) elementary school children, 

174 (91%) upper secondary school students, 

and 109 (89%) high school students . Forty 

teachers (91%; 15 elementary school teachers, 18 upper secondary school teachers, and 

7 high school teachers) and 15 (94%) other 

personnel returned the questionnaire . 

Some results are reported in Table 4. 

Several irritative and nonspecific symptoms 

such as nasal congestion, rhinitis, phlegm, 

shortness of breath, eye irritation, hoarseness, and fatigue, during the previous year 

of the study, were significantly more common among the upper secondary and high 

school students than among the elementary 

school children . After adjusting for age, sex, 

smoking, and atopy, the observed differences among the student groups remained 

significant in nasal congestion, rhinitis, 

phlegm, hoarseness, and fatigue (odds ratios 

not shown). The exposed students also had 

had more long-term and repetitive flu, 

cough, and eye symptoms . Asthma symptoms were common among upper secondary 

and high school students . 

The prevalence of asthma among 

the upper secondary school students was 

high (13%) compared to recently reported 

average prevalence of asthma among this 

age group (4-7% in different in regions of 

Finland) (16) . During the previous 4 

years, 18 new cases of asthma were diagnosed, whereas in earlier 4-year periods 

4-6 cases were diagnosed annually (Table 

4) . Use of health services and medication 

because of asthma was not any higher in 

this group than among youth of the same 

age on average. 

Discussion 

The types of moisture damages can be 

divided into four categories : 

" Incorrect methods of construction, 

maintenance, or repair, which are often 

easily found and solved, can cause damage . Most of the problems in the wooden 

school (C) belonged to this group. 

Damage in the stone school (A) was 

caused by moisture penetrating from 

the ground. Resolution of this type 

of moisture damage is difficult and can 

be expensive . 

Moisture load from ordinary use was 

high in some facilities . The kitchens of 

the school center belonged to this group. 

Water was poured onto the floors on a 

. 

. 

daily basis while washing surfaces, and 

large-scale cooking appliances produced 

steam. Ventilation was not sufficient to 

remove the humidity. This type of moisture load creates a situation with high 

risk of damage. 

The water used in firefighting and 

water leaks were examples of cases in 

which even a well-functioning structure 

became moldy because of an external 

factor . The seasonal climate variation in 

Finland may also cause moist conditions in structures that are suitable for 

microbial growth. 

Success in making correct conclusions on 

. 

the basis of the structural survey depends on 

512 Environmental Health Perspectives " Vol 107, Supplement 3 " June 1999 
p. 5 

MANAGEMENT OF INDOOR AIR PROBLEMS IN SCHOOLS 

Table 4. Comparison of some recurrent symptoms, asthma symptoms, and allergic diseases in the students in elementary, upper secondary, and high schools and reported asthma detection years among the students of the 

school center. 

Elementary 

school students,a 

n l%) 

Upper secondary High 

school students,° school students,° 

n(%) n (%I P 

Nasal congestion 89(48) 

Rhinitis 92(50) 

Phlegm 37(20) 

Shortness of breath 16(9) 

Eye irritation 30(16) 

Hoarseness 40(22) 

Fatigue 48(26) 

Difficulties in exhalation 

Occasionally 2705) 

At school 1 (1) 

Wheezing 

Occasionally 29(16) 

At school 1 (1) 

Allergic rhinitis 22(24) 

Allergic conjunctivitis 26114) 

Asthma 19(5) 

Year 

1980-1984 

1985-1988 

1989-1992 

1993-1996 

125(74) 79(73) 

130(77) 76(70) 

69(40) 36(33) 

34(20) 1706) 

56(33) 39136) 

74(44) 32(30) 

135(79) 85(78) 

60(35) 42(39) 

21 (12) 10(9) 

69(41) 41 (38) 

9(5) 2(2) 

54(32) 36133) 

27116) 20(18) 

22113) 8(7) 

Number of students di agnosed with asthma 

6 

4 

4 

18 

$Use facilities from building B. bUse facilities from buildings A and C. *p< 0.05. **p< 0.01 ; ***p< 0.001 calculated from crude rates . the surveyor's expertise. In the case of moisture problems, knowledge of the structure's 

moisture physics is essential . Buildings must 

be examined systematically, and observations 

may need support from measurements and 

other study methods. It is important to realize that even if damage is small from a structural point of view, it may still lead to 

microbial growth and cause adverse health 

effects . The mitigation of mold problems is 

therefore multidimensional. 

In the microbial study, air and surface 

samples provided basic data for the structural survey and helped locate the moisture 

sites . The conclusions made on the basis of 

the structural survey were supported by the 

microbiological results of the material samples, which verified the presence of microbial growth in the sites considered high risk 

for moisture damage from a technical point 

of view. It was informative to carry out 

these two studies in parallel . Microbial 

growth in structures is caused by excessive 

moisture . By understanding the structure's 

moisture physics and microbiology, the 

origin of the problem often can be found 

and removed. 

Microbial results vary with time, place, 

circumstances of sampling, and methods 

used, and the determinants of total exposure 

to microbes are poorly known so far. Viable 

or culturable microorganisms comprise 

1-10% of the total number of microbial 

cells ; on the basis of our present understanding, the numbers and genera of viable 

microorganisms reflect the microbial status 

of the building and are satisfactory surrogates of the exposure once the sampling has 

been properly focused (4,G15). A microbial 

or structural study alone may not lead to 

independent conclusions, but both are 

needed in evaluating the situation . 

Information obtained from the questionnaire about the facilities where the 

users had experienced problems helped to 

identify the structural problems . The 

unusually high prevalence of respiratory 

symptoms, their association with school 

buildings A and C, and the increased incidence of asthma indicated that a comprehensive investigation of the condition of 

the buildings was necessary. 

The prevalence of asthma among the 

upper secondary school students was twice 

that of the general population prevalence 

of asthma among teenagers (8,16) . Among 

the students who returned the questionnaire, in the previous 4 years, the asthma 

incidence was 3-fold as compared to earlier 

4-year periods . Use of health services and 

medication because of asthma was not 

higher in these teenagers than in other 

teenagers on average, indicating relatively 

moderate or early-phase illnesses . 

Some moisture faults were also found in 

the elementary school (B), which was originally assumed to be a nondamaged reference 

building and was therefore studied only 

briefly. Naturally, the minor damages found 

may also have caused exposure and symptoms of the occupants . However, significant 

differences were found among the health status of the occupants of buildings A and C 

compared to those among occupants of this 

building (B) . Had the reference building 

been undamaged, the observed differences in 

health status of the student groups may have 

been even bigger . On the other hand, the 

degree of the damage depends on several 

variables such as age, use, maintenance, and 

repair of the building. Thus, a completely 

undamaged building may be as abstract a 

concept as is a totally healthy human being. 

The exposure in home environment 

may play a role in the development of respiratory symptoms and asthma, but in this 

study it was not possible to assess the 

domestic situation of each participant . It 

could be assumed that the possible exposure in the home environment was equally 

distributed among the occupants of the 

different buildings A, B, and C. 

The reporting of symptoms associated 

with the buildings may have increased as a 

result of common awareness and publicity 

about the study. Information collected in 

self-administered questionnaires is not 

always as valid as that collected in clinical 

studies (17,18) . The diagnoses of asthma 

were made by a physician and can be 

regarded as objective findings . Symptoms 

associated with mold exposure are otherwise 

nonspecific and difficult to measure. On the 

other hand, a questionnaire study is easy to 

carry out and cost effective, and provides 

direct information from the occupants. 

Special attention was paid to the 

communication with the occupants of the 

buildings during the study. Releasing 

information about the purpose of the 

studies, the measurements, and their results 

to the employees, authorities, schoolchildren, parents, and the media helped to 

open the situation to constructive discussion . Our experience confirmed the importance of public meetings to keep the 

atmosphere open. 

Although the condition of residential 

buildings is ultimately the owner's responsibility, the distribution of risk is more complicated in public buildings . Situations can 

result in which the responsibility is not clear 

but shared among different parties involved. 

To remedy this kind of situation, it may be 

necessary to use outside consultants . 

Environmental Health Perspectives " vol 107, Supplement 3 " June 1999 513 
HAVERINEN ET AL 

The overall purpose of the study was to 

find a useful management strategy to solve 

the critical indoor air situation . It was 

focused not only on supporting the repair of 

damages but also on carefully analyzing the 

original cause of the problem to understand 

the effects . Although it was not possible for 

each part of the study to cover the problem 

in its entirety, the different parts complemented one another. To connect the studies 

in order to construct a systems approach 

and to draw conclusions for use by the town 

administration, it was important to combine 

broad expertise in each part and link them 

by effective cooperation . 

Follow-up studies will be conducted to 

analyze construction solutions and their 

effects on moisture resistance in the structure . A microbial exposure follow-up will 

be done, and the questionnaire study will 

be repeated after the repairs are completed. 

The follow-up study will bring further 

information on the suggested connection 

between exposure and health findings . 

Thus it will be possible to assess the effect 

of elimination of the exposure on the 

decrease of the illness. 

Conclusions 

In buildings A and C, several serious 

moisture problems were identified . The 

conclusions based on the structural survey 

were supported by the results of the microbial study, as the sites of moisture damage 

proved to be sources of unusual microbial 

growth. Respiratory symptoms and general 

symptoms were more common among the 

students occupying these buildings . Each 

part of the study was needed in order to 

analyze and link together the reason for the 

moisture damage, the microbial status of 

the buildings, and the health disorders of 

the occupants. The multidisciplinary 

approach appeared to be a fruitful way to 

solve a critical situation such as this . 

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