Continued Low Symptom Prevalence One Year and Three Years after a Costly Restoration of an Apartment Building with Severe Indoor Climate Problems

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1 Continued Low Symptom Prevalence One Year and Three Years after a Costly Restoration of an Apartment Building with Severe Indoor Climate Problems Göran Stridh 1,*, Kjell Andersson 2 and Inger Fagerlund 3. 1 LGS Environmental AB, Malmö, 2 Environmental Medicine KA, Örebro, 3 Department of Occupational and Environmental Medicine, Örebro, Sweden *Corresponding goran.stridh@gmail.com SUMMARY Due to extensive indoor climate problems in a domestic area with apartments in 14 multifamily buildings, a basic questionnaire survey was initiated showing high prevalence of complaints and symptoms in all buildings. A large restoration program was instigated. The building with the highest symptom prevalence (referred to here as the target building) was restored two years later. Questionnaire surveys for this building using the same questionnaire (MM 050 NA) were performed initially one year before, and one year and three years after the restoration. The results of the surveys before restorative actions were taken showed similar high prevalence of complaints and symptoms and much higher than in the control area located in the same metropolitan area. One year after the restoration, a dramatic decrease in prevalence was observed showing almost identical prevalence values as in the control area. The follow up survey two years later showed similar results. Additional analyses in the last survey showed small differences in symptom prevalence between those who moved in before and after the restoration. These results support the conclusion of a successful restoration and also show that the outcome can be followed effectively by using standardized and tested questionnaires. IMPLICATIONS Standardized and tested questionnaires are cost effective instruments to follow the results of restoration activities over time. It is valuable to extend the follow up period to ensure persistent changes. KEYWORDS SBS symptoms, MM Questionnaire, indoor climate problems, restoration, apartment buildings INTRODUCTION A domestic area in the Stockholm metropolitan area with apartments in 14 apartment buildings was built between 1978 and From the very outset, the tenants complained about indoor climate problems, including ventilation deficiencies and odours, and reported symptoms from the mucous membranes in their upper airways, skin symptoms, fatigue and headache; all symptoms usually included in the SBS concept (sick building syndrome). A self levelling screed containing casein was used in many buildings in Sweden at this time, and roughly 20 million m 2 floor area was constructed in this way during 1977 to In wet conditions and high ph value (concrete has a ph value of 12 to 14) the casein decomposes and ammonia is emitted under the floor covering causing discoloration of the oak parquet floor and break down of plasticizers from the floor coverings emitting, among other chemicals, 2 ethyl hexanol and orto amino acetophenone with an intense odour.

2 The indoor air concentration of these chemicals was, however, low in this domestic area with a mean TVOC value of 127 µg/m 3 and ammonia concentrations usually below 1 ppm (Bornehag, 1995). In spite of this, it was obvious that the tenants were affected. After some basic technical investigations a questionnaire survey was initiated in 1989 covering all adult tenants and children living in the problem area (area A). A neighbourhood domestic area built without this self levelling screed but otherwise judged to be of similar socio economical status was selected as a control area (area B). A large restoration program was initiated with financial support from the government based on the prerequisite that the restoration program should be evaluated. Several studies were initiated, also among those some methodological studies. A nasal histamine provocation test with registration of the swelling of the nasal mucosa by rhinostereometric technique showed that tenants from area A reacted more than tenants in area B (Ohm et al. 1997). It was also shown that tenants moving from area A within two years no longer reported more symptoms than was observed in the nationwide Swedish ELIB study, covering a large sample of the whole domestic stock from the same period (Norlén and Andersson, 1993). A nasal histamine provocation test on a small sample of non allergic persons who had moved from area A but still lived in Stockholm, showed a persistent increased reactivity comparable to those who still lived in the domestic area, in spite of no claimed SBS symptoms (Ohm et al. 1995). In this paper, we report the outcome of multiple questionnaire surveys of the target building, defined as the building with highest symptom prevalence. We also discuss some methodological issues. MATERIAL AND METHODS In all surveys, the MM Questionnaire for dwellings was used (MM050 NA). The MM Questionnaires were developed between 1986 and 1989 and have been used in many specific environments such as offices, hospitals, schools and day care centres as well as dwellings (Andersson, 1998, Reijula and Sundman Digert, 2004, Sundell and Lindvall, 1993). The MM050 NA includes 11 questions about disturbing indoor climate factors and 11 symptom questions. The outcome Yes, often (every week) is evaluated as a positive answer and the recall period is three months. The validity and reliability of the questionnaires have been tested elsewhere (Andersson, 1998, Sundell and Lindvall, 1993). The importance of different wording of the same symptom questions was studied in an area with similar problems and the results are discussed at this conference (Andersson, 2011). The basic survey in area A showed a similar high prevalence of complaints and symptoms in all 14 buildings (each containing roughly 100 apartments) and the tenants related most of their symptoms to the home environment. The response rate was 84 %. Both complaints and symptoms were prevalent and most symptoms were presumed related to the indoor environment. The tenants complained about stuffy, dry air and unpleasant smell besides dust and dirt and reported high symptom prevalence of general symptoms, mucous membrane irritation and skin problems The target building, defined as the building with the highest prevalence of symptoms, could not be restored at first for legal reasons. It was, therefore, possible to ask the tenants in this building twice; one year apart before the restoration activities were initiated. One year and three years after the restoration, follow up surveys were performed. All surveys were made at the same time of the year (March to April) to include the heating season (winter time). In this paper, the results of the two surveys before and the two surveys after the restoration are presented.

3 HOME ENVIRONMENT (often bothered) % SYMPTOMS (yes, often) % Noise Dust and dirt Other Draft Room temperature too high Hands dry, itching, red skin Other Fatigue Feeling heavy headed Headache Scaling/itching scalp or ears Passive smoking 40% 80% Varying room temperature 20% 40% Nausea/dizziness Static electricity, often causing shocks Room temperature too low Dry or flushed facial skin Cough Difficulties concentrating Unpleasant odor Dry air Stuffy "bad" air Itching, burning or Hoarse, dry throat irritation of the eyes Irritated, stuffy or runny nose Target building (n=155) Target building (n=155) Building related Figure 1. The three month prevalence of often disturbing indoor climate factors and symptoms for the target building at the basic questionnaire survey. The result for reference area B is shown as a shadowed area in the graph. RESULTS The perceived indoor climate and reported symptoms for the target building at the basic survey is presented in Figure 1. The outcome at all four occasions is presented in Tables 1 and 2. In the tables, the external reference values are presented. The difference between the prevalence figures at the four occasions and the reference data are tested using Chi 2 technique for differences between proportions. The response rates varied between 84% and 73%. The outcome of the two surveys before the restoration was made is similar and they both deviate strongly from the results one year and three years after the restoration. After the restoration, the prevalence of both disturbing indoor climate factors and symptoms are almost identical to those of the reference area. No significant differences in symptom prevalence were seen between those who moved in after the restoration (n=62) and those who stayed (n=51) in the last survey three years after the restoration (Table 3) Table 1. The prevalence of often disturbing indoor climate factors in the target area at four occasions (one and two years before and one and three years after the restoration). The figures are given in percentage. Target building Control reference n=155 n=132 n=145 n=116 n=292 Draft 31*** 31*** High temperature Variable temperature 15** Low temperature 21** 30*** Stuffy bad air quality 50*** 51*** Dry air 69*** 66*** Unpleasant smell 28*** 26*** Static electricity Tobacco smoke Noise Dust and dirt 52*** 51*** 24 34* 23 *p<0.05, **p<0.01, ***p<0.001 (compared to reference)

4 Table 2. The prevalence of symptoms in the target area at four occasions (one and two years before and one and three years after the restoration). The figures are given in percentage. Target building Control reference n=155 n=132 n=145 n=116 n=292 Fatigue 57*** 50*** Heavy headedness 29*** 27*** Headache 28*** 21*** Dizziness 12*** 7* Concentration difficulties 8* Eye irritation 34*** 31*** Nasal irritation 41*** 34*** Dry throat 35*** 33*** Cough 18** 20*** Dry facial skin 27*** 22*** Scalp 25*** 24*** Dry hands *p<0.05, **p<0.01, ***p<0.001(compared to reference) Table 3. The prevalence of symptoms in the 1994 investigation among those who moved in before or after the restoration of the target building. The figures are given in percentage. Target building Control Moved in before Moved in after reference n=51 n=62 n=292 Fatigue Heavy headedness Headache Dizziness Concentration difficulties Eye irritation Nasal irritation Dry throat Cough Dry facial skin Scalp Dry hands DISCUSSION The results of the restoration were extraordinary, with a dramatic drop in both complaints and reported symptoms to the same level as for the control domestic area. Even more interesting was that this situation persisted for years which must indicate a real improvement and is, due to the relatively long time passed between questionnaires, not explained by a placebo effect. This conclusion was further supported by similar results from the other buildings which were all followed up with questionnaire surveys after the restoration activities were made. It was possible to study the reactivity of the nasal mucosa among several small samples of tenants in both area A and control area B. There was clear evidence of increased nasal reactivity among those living in area A (Ohm et al. 1997). Further support of a real impact on the nasal mucosal membranes of those living in area A was the study which showed persistent increased reactivity among those who had moved from area A although they did not report more SBS symptoms (Ohm et al. 1995).

5 Similar findings were seen from a study where teachers who had worked in a school with humidity problems for years showed increased nasal reactivity compared to teachers from a control school one year after a successful restoration (Rudblad et al. 2001). Follow up studies showed that the increased reactivity to histamine persisted for more than three years but at the 6 year follow up study no significant difference could be seen (Rudblad et al. 2005). Further support for a successful restoration in this specific case was the follow up investigations of students entering both this school and the control school during three years, which showed no difference in nasal histamine reactivity between students in the two schools or between the three annual investigations (Rudblad et al. 2004). It therefore seems obvious that the SBS symptoms can disappear, although an increased reactivity in the mucous membranes persists. This might also explain why there was no difference in symptom prevalence among those who moved into the target building after the restoration and those who had lived there for years. Although the tenants were obviously affected by the indoor climate, technical measurements showed emissions of different chemicals under the PVC floor covering but very low levels in the indoor air. In spite of many correlation studies, we still do not know any relation between specific agents and indoor related symptoms, mostly due to the fact that we still do not know the biological mechanism behind it (Andersson, 2008). The outcome from the two surveys before and the two after restoration activities give very stable results. These results support the conclusion of a successful restoration and also show that the outcome can be followed effectively by using standardized and tested questionnaires. CONCLUSIONS Follow up studies after restoration of buildings with indoor climate problems can be made in a cost effective way by using standardized and tested questionnaires. This case study shows stable and assessable questionnaire results, although the technical measurements only show low levels of indicator chemicals in an area with obvious health related problems.

6 REFERENCES Andersson K Epidemiological approach to indoor air problems. Indoor Air, 9 (Suppl. 4), Andersson K Indoor climate and health: what do we really know? Indoor air 2008, august 2008, Copenhagen, Denmark. Paper ID:We9K1 (9 pp). Andersson K, Stridh G, Fagerlund I The Significance of Wording in Indoor Climate Questionnaires. Indoor Air 2011 conference, Austin. Bornehag C G Pattern analysis of VOC in indoor air. Proceedings of Healthy Buildings 95, Vol.1, Ohm M, Juto J E, Andersson K, Bodin L Nasal Histamine Provocation of Tenants in a Sick Building Residential Area. Am J Rhinology, 11(2), Ohm M, Juto J E, Andersson K Does the nasal reactivity change after removal from SBS domestic area to areas without SBS problems? In Indoor Air: An Integrated Approach. Morawska L, Bofinger ND, Maroni M (eds), Elsevier, Norlén U, Andersson K Indoor climate in Swedish dwellings. Proceedings of Healthy Buildings 95, Vol.1, Reijula K, Sundman Digert Assessment of indoor air problems at work with a questionnaire. Occup Environ Med, 61, Rudblad S, Andersson K, Stridh G, Bodin L, Juto J E Nasal Hyperreactivity among Teachers in a School with a Long History of Moisture Problems. Am J of Rhinol 15, Rudblad S, Andersson K, Stridh G, Bodin L, Juto J E Nasal histamine reactivity among adolescents in a remediated moisture damaged school a longitudinal study. Indoor Air, 14, Rudblad S, Andersson K, Stridh G, Bodin L, Juto JE Nasal mucosal histamine reactivity among teachers six years after working in a moisture damaged school. Scand J Occup Environ Health, 31(1), Sundell J, Lindvall T Indoor air humidity and the sensation of dryness as risk indicators of SBS. Indoor Air, 3,