~ ) Pergamon Energy Convers. Mgmt Vol. 35, No. 5, pp. 385 394, 1994 Copyright ;~ 1994 Elsevier Science Ltd

Printed in Great Britain. All rights reserved 0196-8904/94 $7.00 + 0.00

O N T H E E N E R G Y C O N S U M P T I O N A N D I N D O O R A I R

Q U A L I T Y I N O F F I C E A N D H O S P I T A L B U I L D I N G S I N

A T H E N S , H E L L A S

A. ARGIRIOU, I D. ASIMAKOPOULOS, ~ C. BALARAS, 1 E. DASCALAKI, 1 A. LAGOUDI, z M. LOIZIDOU, 3 M. SANTAMOURIS2t and I. TSELEPIDAKI 2 ~PROTECHNA Ltd, Themistokleous 87, GR 106 83 Athens, 2Department of Physics, University of Athens, Ippokratous 33, GR 106 80 Athens and 3Chemical Engineering Department, National Technical

University, Athens, Greece

(Received I8 December 1992; received ~ r publication 2.? September 199.?)

A~t rae t - -Ene rgy audits and a parallel investigation of indoor air quality in 30 air-conditioned and naturally ventilated office buildings in Athens, as well as a hospital building, have been underway since 1990. These audits have been conducted for the first time in Hellas and include information on the buildings' energy consumption, indoor and outdoor air quality, employee health symptoms and comfort conditions. The results indicate that there are serious IAQ problems in office buildings, which have been found to be the direct cause for a number of employee health problems related to the working environment. Preliminary measurements of NO 2 and SO, in the indoor environment of a hospital show that the concentrations do not exceed the W HO limit values.

Energy audits Indoor air quality phur dioxide measurements

Health symptoms Comfort Nitrogen dioxide and sul-

I N T R O D U C T I O N

Energy consumption in buildings is a major parameter having a direct impact on the thermal comfort and indoor air quality of a building. However, very few studies demonstrating the relationship of energy with indoor air quality are available. In addition, over the past few years, the so-called "sick building" syndrome has attracted a lot of attention. It has been observed in old and new buildings, as a result of the contamination of indoor air from building materials, human activities, outdoor pollutants, ineffective ventilation and malfunction of heating and cooling systems due to inadequate maintenance. This is a major problem due to the health effects of indoor air on the buildings' occupants.

In particular, health symptoms exhibited by employees in office buildings indicate that there is a direct relation between indoor air quality and human health. This is primarily due to the fiact that office employees are exposed to the building's indoor conditions for long periods.

To overcome this kind of problem in the future and to resolve the existing ones, we must first identify the sick buildings, pinpoint the sources of the problem and then proceed with the necessary actions. Questionnaire studies, as well as short and long period monitoring, are used to evaluate the sick building syndrome in buildings.

Questionnaires help to understand and identify the problems. They are designed to deal either with health symptoms [1] or with energy [2] and pollution aspects [3]. Monitoring of a building can provide accurate information regarding concentration of specific pollutants from which, therefore, to proceed taking the necessary actions.

This paper deals with questionnaire surveys in office buildings, as well as with indoor air quality monitoring in hospitals. These buildings exhibit the more important indoor air quality problems due to the relatively high number of employees in office buildings and the specific conditions presented in hospitals. Surveys of office buildings have been underway since 1990. The audits which have been conducted and results presented herein are for 30 air-conditioned and naturally ventilated

*To whom all correspondence should be addressed.

385

386 ARGIRIOU et al.: ENERGY CONSUMPTION AND AIR QUALITY IN ATHENS

buildings located in the Athens greater metropoli tan area. The city o f Athens was selected because it exhibits a very impor tant air pollution problem having a direct impact on indoor air quality.

The objective of this work is to investigate indoor air quality (IAQ) problems in office and hospital buildings and also to examine the impact o f the building's energy consumption. The collected data are analysed in order to develop correlations between the various parameters, which will then provide useful information on the behaviour o f naturally and mechanically ventilated office buildings and their effects on IAQ. The obtained results provide a representative picture of I A Q in existing office and hospital buildings and can be used as guidelines for possible interventions and improvements in new buildings.

This study has been carried out for and partly supported by The Hellenic Ministry o f Research, Energy and Technology, The Hellenic Ministry o f Heal th and Social Services, and the Hellenic Productivity Centre.

M E T H O D O L O G Y

The auditing o f the office buildings was conducted by a trained panel o f engineers and scientists, on average four auditors per building. The investigation was based on a carefully constructed s tandard questionnaire for evaluating ou tdoor and indoor air-quality conditions, employees ' health symptoms, and comfor t condit ions inside the building.

The procedure was based on a questionnaire which the auditors had to complete and then a questionnaire that the employees in each office building had to complete. For the first one, the responses o f the auditors were recorded upon their arrival at the site, for the air quality outside and inside the building, as described in Ref. [3]. For the second questionnaire, female and male employees, were requested to respond on whether they exhibit any health symptoms from a list containing 31 symptoms [1], shown in Table 1. On average, four employees were interviewed by each auditor.

Table 1. Number of total health symptoms and percent of occurrences reported by employees in office buildings in Athens and Z scores. Values in parentheses are in

percent

Type of ventilation

Mechanical Natural Z Symptom (312 employees) (164 employees) score

Eye irritation 182 (58.3) 102 (61.4) 0.657 Eye infection 41 (13.1) 30 (18.1) 1.463 Dry/sore throat 60 (19.2) 31 (18.7) 0.133 Cough 58 (18.6) 35 (21.1) 0.657 Excessive phlegm 20 (6.4) 8 (4.6) 0.798 Runny nose 45 (14.4) 14 (8.4) 1.899 Sinus infection 7 (2.2) 1 (0.6) 1.298 Bronchial pneumonia 6 (1.9) 0 (0.0) 1.776 Shortness of breath 59 (18.3) 40 (24.1) 1.50 I Wheezing 5 (1.6) 0 (0.0) 1.637 Asthmatic attacks 6 (I .9) 0 (0.0) 1.776 Bronchitis 15 (4.8) 6 (3.6) 0.609 Headaches 195 (62.5) 79 (47.6) 3.136 Disturbed concentration 103 (33.0) 69 (41.6) 1.865 Dizziness 89 (28.5) 50 (30. l) 0.367 Unusual fatigue 97 (31.1) 41 (24.7) 1.470 Drowsiness 98 (31.4) 47 (28.3) 0.702 Difficulty in sleeping 34 (10.9) 9 (5.4) 2.001 Rashes 14 (4.5) 10 (6.0) 0.715 Nasal irritation 37 (11.9) 11 (6.6) 1.835 Nosebleed 7 (2.2) 1 (0.6) 1.298 Nasal sores 6 (1.9) 2 (1.2) 0.568 Nausea 12 (3.8) 5 (3.0) 0.450 Vomiting 6 (I .9) 2 (1.2) 0.568 Diarrhoea/loose stool 2 (0.6) 0 (0.0) 0.968 Chest pain 16 (5.1) 6 (3.6) 0.745 Abdominal pain 10 (3.2) I (0.6) 1.805 Menstrual problems 7 (2.2) 2 (1.2) 0.766 Unusual thirst 34 (10.9) 19 (11.4) 0.166 Whole body ache 15 (4.8) 12 (7.2) 1.082 Fever 6 (1.9) 5 (3.0) 0.164

A R G I R I O U et al.: E N E R G Y C O N S U M P T I O N A N D AIR Q U A L I T Y IN ATHENS 387

The questionnaire for thermal comfort included a general question for one employee on each floor of the audited building, in order to classify the building for comfort, based on the Predicted Mean Vote (PMV) scale [3]. Their responses were recorded on a scale ranging between extremely hot and extremely cold for the summer and winter periods.

The selection of the buildings was made in such a way as to cover various locations in the extended Athens metropolitan area, variable size and year of construction of buildings, private or public ownership, and different cooling/heating systems. A total of 18 mechanically ventilated (M/V) and 12 naturally ventilated (N/V) buildings have been audited.

Additional information on the buildings was also collected including the energy consumption of the audited buildings, and for completeness, all major mechanical and electrical information on the building and its construction (building materials, orientation, etc). This information is available in Ref. [4].

Monitoring of a hospital building was performed in order to determine nitrogen dioxide and sulphur dioxide levels which were measured near the entrance of the surgery room. Concentration of pollutants in this area should be quite low in order to avoid contamination and to minimize health risks to the patients. The hospital is located in the centre of the Athens area near a central avenue with heavy traffic. Mechanical and natural ventilation systems were used in order to satisfy the necessary ventilation standards.

Nitrogen dioxide measurements were taken on a 24-h basis, covering a period of 4 months (March, June, September and December 1990). The NO2 determination was based on the Griess- Saltzntan method, while the sulphur dioxide was monitored for 3 months (March, June, December) on a 24-h basis using the TCM-pararozaniline method [5].

A N A L Y S I S OF T H E R E S U L T S

Office buildings A total of 30 office buildings were audited in the Athens greater metropolitan area, including

18 M/V and 12 N/V buildings. The number of employees which were questioned in this study include 312 in mechanically ventilated buildings and 166 in naturally ventilated buildings.

The results for the number of health symptoms reported by the employees in each type of building are given in Table 1. For each symptom, the first number gives the total number of occurrences reported by all the employees questioned and in the parentheses is the percentage number of employees reporting that symptom.

The symptoms with the highest reporting rates were for the mechanically ventilated buildings: Headaches (62.5%), Eye irritation (58.3%), and Disturbed concentration (33.0%), while in naturally ventilated buildings, the most common symptoms were: Eye irritation (61.4%), Headaches (47.6%), and Disturbed concentration (41.6%).

Natural ly vent i la ted office bui ld ings

D ~ ~ C

Symptoms:

A: Eye irritation B: Headaches

D: Dizziness E: Drowsiness

Mechanica l ly venti lated office bui ld ings

F t B E B

D ~ C

C: Disturbed concentration

F: Unusual fatigue

Fig. 1. Percent of reported symptoms by employees in office buildings.

388 ARGIRIOU et al.: ENERGY CONSUMPTION AND AIR QUALITY IN ATHENS

/

S at u r all y ven t. ~ , , , / / ' , / ' , / " / / ' / / / / / / 1

Mechanically vent. / / " / / / / / / / / / / / . ~

I I I L 1 0 l 2 3 4 5

No. of symptoms/person

Fig. 2. Number of symptoms per person reported by the employees in naturally and mechanically ventilated office buildings.

The percentages of the six most commonly reported symptoms by the employees, in the two types of buildings, are shown in Fig. 1. Naturally ventilated buildings exhibit a higher percentage of symptoms in eye irritation, mainly because most of the N/V buildings which have been audited are located in the downtown area where the outside air quality is poor. Employees in N/V buildings also reported higher percentages of disturbed concentration. This is probably caused again by the fact that these buildings are located in areas with high rates of traffic. Open windows, which are required for ventilation purposes, limit the ability for noise control.

On average, the number of symptoms in mechanically ventilated buildings is slightly higher than in naturally ventilated buildings (Fig. 2). Similarly, the percent of employees with at least one symptom in M/V buildings (89.53%) is higher than the corresponding percentage in N/V buildings (87.8%), with an average of 88.86% for all buildings (Fig. 3).

The statistical significance between the observed frequency of occurrence of a health symptom as reported by the employees (Table 1) and the expected frequency on non-occurrence has been quantified by the X 2-test of significance with 1 d.f., calculated as follows:

Z 2 _ (Obs.frequency - 0.5 No. of employees) 0.25 No. of employees (l)

The expected frequencies are computed on the basis of a null hypothesis H0. In this case, the null hypothesis to be tested was that the frequency of occurrence of one health symptom does not

N/V office buildings

M/V office buildings

"////////////////////~

/////////////,////////~

All office buildings "////////'////////////II

1 l I l I l I I I I 0 lO 20 30 40 50 60 70 80 90 lOO

Employees with at least one symptom (%)

Fig. 3. Percent of employees in office buildings with at least one health symptom.

ARGIRIOU et al.: ENERGY CONSUMPTION AND AIR QUALITY IN ATHENS 389

exhibit a statistically significant difference from its non-occurrence. The critical value is taken at the 0.05 significance level and for 1 d.f. equals 3.84. If, under this hypothesis, the computed value of Z 2 from equation (1) is greater than the critical value, one may conclude that the observed frequencies differ significantly from the expected frequencies, and the null hypothesis is rejected at the 0.05 level of significance. Otherwise, the null hypothesis is accepted.

The X 2-test values were calculated for every heatlh symptom using equation (1). Accordingly, there is a statistically significant difference between the occurrence of a symptom from its non-occurrence. However, for the symptom of Headaches in naturally ventilated buildings (where Z2= 0.386 < Z g.95 = 3.84) the null hypothesis is accepted. This means that the symptom of headaches exhibited by employees in N/V buildings is not related to the type of ventilation system in the building, but rather it is caused by the poor air quality of the outdoor air which is allowed into the building.

Based on the available sample information, the probabilities of occurrence of a health symptom by the employees in one of the two groups of buildings (mechanically or naturally ventilated buildings) p~ and P2, respectively, have also been compared with each other. For that purpose, the following two hypotheses were tested:

H,,: Pl = P2, there is no difference between the two probabilities H~: p~ :~ P2, there is a difference between the two probabilities

where H0 denotes the null hypothesis, and H~ denotes the alternative hypothesis. In order to decide between the two hypotheses, the following random variable (or Z score) is assumed to follow a normal distribution N (0,1)

t'l + v~ (p (1-- p))J'z \ r, t 2 /

where vt =number of audited employees in M/V buildings=312, r2=number of audited employees in N/V buildings= 166, 21 =observed frequency for M/V buildings, )-2 =observed frequency for N/V buildings. An estimate of the population proportion (p) is given by:

(2~ + 22) P - ( v , ~ v 2 ) " (3)

For a two-tailed test, the null hypothesis is rejected at a 0.05 level of significance if the Z score lies outside the critical region of - 1.96 to 1.96, otherwise the null hypothesis is accepted. The Z score for all the health symptoms is given in Table 1. Accordingly, the null hypothesis is rejected for the symptoms of Headaches and Difficulty in sleeping.

Similarly, one may examine the following two hypotheses,

H0: Pl = P2, and H~: Pt > P2.

For a one-tail test, the null hypothesis is rejected at a 0.05 level of significance if the Z score is greater than or equal to the critical value of 1.645, while the null hypothesis is accepted if Z < 1.645. Accordingly, the proportionality is statistically significantly greater in the case of M/V than in N/V buildings for the symptoms of Headaches, Difficulty in sleeping, Runny nose, Disturbed concentration, Nasal irritation, Abdominal pain, Asthmatic attacks, and Bronchial pneumonia.

The number of reported symptoms per person has been correlated with the number of employees in the building. The results, as shown in Fig. 4, do not indicate that there is a relationship between the two parameters. However, the number of symptoms per person increases with the number of occupants per square meter in naturally and mechanically ventilated buildings (Fig. 5). Overall, an increase of the number of employees occupying a certain space in the building influences the indoor air quality and increases the number of employees' health symptoms. It appears, according to Fig. 6, that, in mechanically ventilated buildings, the number of health symptoms reported by the employees is relatively higher than in naturally ventilated buildings.

With regard to thermal comfort, overall, the percent of dissatisfied people in naturally ventilated buildings is substantially higher than the corresponding percentage for the M/V buildings. In only

ECM 35/5 B

390 A R G I R I O U et al.: E N E R G Y C O N S U M P T I O N A N D AIR Q U A L I T Y IN ATHENS

All office bu i ld ings

8 -

6

~ u

2 4 e ~

E

6 2 Z

m

0 0 •

m

o ~

I I I L L I 1 I 50 100 150 200 250 300 350 400

Employees per bui ld ing

Fig. 4. Number of health symptoms per person related to the number of employees in the olfice building.

two M/V buildings, one case during the summer and one during the winter period, were the employees totally unsatisfied with the thermal comfort in the building. On the other hand, in N/V buildings, only two audited buildings were reported by 50% of their employees as providing thermal comfort. This is due to the fact that, in most N/V buildings, the prerequisites for correct natural ventilation (cross wide openings in rooms, at least two sides open to the outside environment) are non-existing. Consequently, to achieve thermal comfort, the building has to be designed according to the fundamental principles for natural ventilation in order to expect satisfactory results and provide thermal comfort.

The results on the air quality inside the buildings, as judged by the auditors, are presented in Fig. 7. It appears that, for the N/V buildings, approximately half of the buildings exhibit over 50% of dissatisfaction. However, all of these buildings are located in areas with high outdoor air pollution.

It has been reported [6] that natural ventilation can be successfully utilized to reduce the energy consumption in office buildings. Overall, M/V buildings consume higher amounts of energy than the N/V buildings, as shown in Fig. 8. The average energy consumption per m 2 for the naturally ventilated buildings is 128.6 kWh/m 2, while for the mechanically ventilated buildings is 171 kWh/m 2.

• Naturally vent. + Mechanically vent.

* All buildings 1oo - . - ~ . . . _ _ - - . ~ .

80

20 • ~ ~ s ~

0 - - ~ T ' - - ~ ' ~ ' + I I I I I t 1 2 3 4 5 6 7 8

No. of s y m p t o m s per person

Fig. 5. Cumulative distribution of the number of health symptoms per person exhibited by the employees in otfice buildings. (Q) Naturally ventilated; ( + ) mechanically ventilated; ( , ) all buildings.

ARGIRIOU e t al.: ENERGY CONSUMPTION A N D AIR QUALITY IN ATHENS 391

8 --

7 - i .

~ 6 -

E 5 - - © ~, 4 - -

~3 2

6 I Z

o o

c-

o e~

N/V office buildings

++ +

+ ~ + + / +

- - +

I I I 0.06 0.12 0.18

Occupants/m 2

M/V office buildings 8 m

~ 7

j ~ 6 E 5 o ~ 4

~3 ~ 2 o

t I z I 0.24 0.30 0 0.18

- - +

__+ +++

- - +_ + _%----'--'+

+

I I 0.06 0.12

Occupants/m 2

Office buildings in Athens 8 - -

o 7 - -

6 -- + + ++

O E 5 -- + + + + ~ . . . . I / / " 4 + ++ ___~ +¥+ +

E ~ 4 - """ + +4_+ + ~ 3 +

~ 2 - - +

z ~ I I I I I 0 0.06 0.12 0.18 0.24 (t.30

Occupants/m 2

Fig. 6. Number of health symptoms per person exhibited to the number of occupants

N/V office buildings ~00 - 7 ~"

/ oHn 60 / /

40 / /

20 ~] H / / '.~, ~ ~ I / I I I

0 I 2 3 4 5 6 7 8 9 10 11 12

I 0.24

Building number

by the employees in office buildings in relation per square meter.

M / V o f f i c e b u i l d i n g s

100

6O

4°

,H,, R I I I I IAI I 0 1 2 3 4 5 6 7 8 9 101112 1314 151617 18

Building number

Fig. 7. Percent of dissatisfied people in office buildings (data for Nos 9 and l0 in the case of M/V buildings

500 --

400 --

300 --

N/V office buildings

2°° H A v e r a g e = 128.6

100

H N 0 1 2 3 4 5 6 7 8 9

Building number

is not available).

I 400

/ 300 - / / '"~ / ¢~

//////////.~ ~ r'~ ~'~ 200100 l

1 0 1 1 1 2 0 1

M/V office buildings

A v e r a g e = 171

2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8

Building number

Fig. 8. Annual energy consumption in audited office buildings in Athens (data for No. 4 in the case of M/V buildings is not available).

I 0.30

392 A R G I R I O U et al.: E N E R G Y C O N S U M P T I O N A N D A I R Q U A L I T Y IN A T H E N S

6 - -

e~

.~ 5 --

4 e.~

2 3 e ~

~, 2

• 1 o

Z

N/V o f f i c e b u i l d i n g s

• . "

50 I I [ I I I

100 150 200 250 300 350

E n e r g y c o n s u m p t i o n ( k W h / m 2)

E

o

6 Z

l 400

8 - -

7 - I .

6 - -

e-~ 5 --

4 --

3 --

2 - -

1 - -

M/V o f f i ce b u i l d i n g s

I I I I I I t 50 100 150 200 250 300 350

E n e r g y c o n s u m p t i o n ( k W h / m 2)

I 400 45O

8

0 u~

"~ 6

m .

~ 4

2

6 Z

A l l o f f i c e b u i l d i n g s

I I I I I ] I t I 50 100 150 200 250 300 350 400 450

E n e r g y c o n s u m p t i o n ( k W h / m 2)

Fig. 9. N u m b e r of heal th s y m p t o m s per person exhibi ted by the employees in office bui ld ings in re la t ion to the bui ld ings ' energy consumpt ion .

The number of symptoms per person do not exhibit any relation with the building's energy consumption, Fig. 9. In particular, for the N/V buildings, the small positive slope of the regression line and, for the M/V buildings, the small negative slope, can not be considered significant, since there are not enough available data and they also exhibit a great scatter.

20 --

15 --

1 0 - -

5 n.HH 34 36 38 40 42

M e a s u r e d NO 2 c o n c e n t r a t i o n s in a h o s p i t a l b u i l d i n g in A t h e n s

7"7/ / /

/ /

/ / / /

,.--, / / / / z / / / / /

/ /

/ /

Z . 44 46 48 50

Y,

52 54 56 58 60 62 64 66 68 70

NO 2 c o n c e n t r a t i o n s (I.tg/m 3)

Fig. I0. Frequency d i s t r ibu t ion of measured N O 2 concen t ra t ion in a hospi ta l in Athens.

ARGIRIOU et al.: ENERGY CONSUMPTION AND AIR QUALITY IN ATHENS 393

Z

Measured SO 2 concen t ra t ions in a hospi ta l bu i ld ing in A thens

14

12

10

8

6

4

2

0

I

15 16 17 18 19 20 21

7~

/ /

/ / Z Z

22 23 24 25 26 35 36

I 27 28 29 31) 31 32 33 34

S O 2 c o n c e n t r a t i o n s (I.tg/m 3)

Fig. 11. F r e q u e n c y d i s t r i bu t ion o f m e a s u r e d SO 2 c o n c e n t r a t i o n in a hosp i ta l in A t h e n s

Hospital building

Regarding the quantitative assessment of air pollutants in the hospital, the measured values of NO~ and SO2 are given in Figs 10 and 11. The mean measured 24-hr NO~ indoor concentrations during the 4 months of the study were in the range of 33 67/~g/m 3. Figure 10 refers to the frequency distribution of the NO2 concentrations for the sampling period. It shows that 82% of the values were above 40/~g/m 3, 36% were above 50/~g/m 3 and 8.3% exceeded the level of 60 #g/'m 3. These values are quite lower than the WHO maximum guideline value (150/~g/m3), but they are significantly higher than the reported concentrations for buildings without a known indoor source [7 9].

Measurements of NO2 levels at a monitoring station near the hospital showed that the outdoor concentrations were significantly higher than the corresponding indoor values, very often exceeding the health standards. Measured values on an hourly base were in the range of 12 500 i tg/m 3, while the 24-h average values ranged between 50 and 200 ~tg/m 3 [10].

No significant seasonal variation was observed in the NO: concentrations, although the levels of NO2 in March and June were slightly higher than in September and December. The mean concentrations for these months were 52.2, 51.2, 44.7 and 44. I/~g/m 3, respectively. For the outdoor environment, the respective NO 2 values were 123.3, 139.6, 127.6 and 104.4 # g/m 3. This indicates that the indoor-to-outdoor ratio (I/O) is less than unity, the range being 0.35 0.42. Accordingly, one may conclude that there are no indoor NO2 sources. The outdoor polluted environment is the primary NO2 source, and the indoor NO,, levels are directly related to the infiltration and the decay rates.

The mean 24-h SO, concentrations, taken for 3 months, ranged between 15 and 35 I~ g/m~, and they were substantially lower than the WHO 24-h maximum limit (100 1501~g/m~). The frequency distribution is shown in Fig. 11. The mean monthly concentrations were found to be 26.0, 20.2, 23.6/ag/m 3 for March, June and December, respectively, and they did not show any seasonal variation.

These results imply that the high outdoor 24-h SO2 concentrations, which were approximately in the range of 25 350/,tg/m 3 [10], are not reflected in the indoor environment. This must be due to the high reactivity of SO2 in the indoor surfaces, reducing its indoor levels. Additional measurements of the indoor air quality have been performed in various buildings in the Athens area, and the results are available elsewhere [I 1].

C O N C L U S I O N S

For the first time in Hellas, a survey of office and hospital buildings has been underway since 1990 in order to investigate the sick building syndrome. This phase of the investigation covered 30 naturally and mechanically ventilated buildings in the Athens greater metropolitan area, which

394 ARGIRIOU et al.: ENERGY CONSUMPTION AND AIR QUALITY IN ATHENS

was conducted based on questionnaires (for the employees) and on-site visits of a trained panel of engineers and scientists. Monitoring of specific pollutants has been performed for a central hospital in Athens.

It appears from this investigation that the office buildings clearly exhibit an indoor air quality problem, which is the direct cause of a number of employees' health symptoms. The highest percent of reported symptoms were the following: eye irritation, headaches, dizziness, drowsiness and unusual fatigue. The indoor air quality problem in most of the N/V buildings is also influenced by the poor outdoor air quality, which is a major problem in the area of Athens. A significant number of employees also complained for disturbed concentration, which is directly related to the location of the audited buildings in areas of heavy traffic and high outdoor noise levels.

A number of other correlations which were attempted between the reported employee health symptoms and the buildings' energy consumption and thermal comfort did not prove significant. It appears, that the information one may collect from conducting a study based on standard questionnaires has been exhausted.

For the next stage of the investigation, the study will include on-site measurements of the air pollutants in office buildings in Athens, which will then be extended to other major Hellenic cities.

Monitoring of the NO2 and SOz levels in a hospital building did not exceed the WHO limit values for ambient air. However, the NO2 concentrations found in this study were higher than the corresponding concentrations measured in buildings without known indoor sources. This is primarily due to the high concentration of pollutants in the outdoor environment.

Acknowledgements--This work was funded by The Hellenic Ministry of Research, Energy and Technology, The Hellenic Ministry of Health and Social Services, and the Hellenic Productivity Centre.

R E F E R E N C E S

1. A. Hedge, E. M. Sterling and T. D. Sterling, Proc. o fASHRAE IAQ 88 Conference, Atlanta, Georgia, p. 31 (1988). 2. O. Valbjorn, H. Hagen, E. Kukkonen and J. Sundell, SBI Report 212, Danish Building Research Institute (1990). 3. P. O. Fanger, J. Lauridsen, P. Bluyssen and G. Clausen, Energy Bldgs 12, 7 (1988). 4. Energy Conservation in Public/Commercial Buildings, 2nd Progress Report, Submitted to Hellenic Ministry of Industry

and Research, and ELKEPA by Protechna Ltd, Athens (1991). 5. M. Katz, American Public Health Association, 1015 Eighteen Street N.W., Washington, DC 20036, APHA Intersociety

Committee (1978). 6. A. Argiriou, C. Balaras, E. Dascalaki, A. Gaglia, G. Goudelas, K. Moustris, M. Santamouris and M. Vallindras, Int.

Conference Quality of the Indoor Environment, Athens, Hellas (1992). 7. B. Leaderer, R. Zagraniski, M. Berwick and J. Stolwijk, Am. J. Epidemiol. 124, No. 2 (1986). 8. E. Palmes, C. Tomczyk and A. March, JAPCA 30, 392 (1979). 9. COST Project 613, European Concerted Action, Indoor Air Quality and its Impact on Man (1989).

10. PERPA, Atmospheric Pollution Organization of Athens, monthly published data (1990). 11. M. Loizidou, D. Asimakopoulos, A. Lagoudi and M. Petrakis, Int. Conference Quality of the Indoor Environment,

Athens, Hellas (1992).