Abstract In response to symptom complaints of unionized workers, a government labour department ordered a symptoms survey of occupants at a large courthouse building contaminated with mold. The analysis and results of the survey were time sensitive in order to decide whether the building should remain open or closed during remediation. The English version of the Swedish MM-040-EA Indoor Climate Work Environment questionnaire along with four item asthma screening questionnaire developed by Venable et at., were selected as investigation instruments. A one page, two sided survey was distributed to 288 occupants and 82.9% responded within a one week deadline. Relative risk rations were calculated comparing respondents’ symptom prevalence with published data for buildings without air quality problems. Relative risk ratios exceeded 5.00 for cough, throat and skin symptoms experienced on at least a weekly basis. One third (76) of the respondents satisfied a NIOSH “sick building syndrome” symptom case definition. Even more (94) screened positive to the asthma screening questions, 60 of whom reported never having been diagnosed with asthma. Comments written on the survey form indicated aggravation of pre-existing asthma and recent diagnosis of new onset asthma. The results presented within 8 days of the survey response deadline. These survey instruments performed very well and were easily analysed in a very short time frame. It is an effective tool for validating building occupants’ concerns and supplements the traditional technical aspects of an IAQ evaluation. These surveys are recommended to hygienists in similar situations facing tight deadlines.

Questions: 1.How symptomatic are the occupants? 2.How does this building compare to others? 3.Can we identify any problem areas?

Survey Instruments & Methodology: used Swedish “MM-Questionnaire” 1 compared with data for building without air quality problems (206 respondents) 2 used validated asthma screening questions 3

Survey Distribution: 293 individually addressed surveys sent 5 returned blank –3 on maternity leave –2 no longer working in building 239 completed surveys returned 15 completed surveys returned after deadline (not included in this analysis; but retained for follow-up)

Response Rate: 239 completed responses received of a possible 288 for a 82.9% response rate a response rate of greater than 80% is needed to ensure the effect of a response bias (symptomatic more likely to respond) is negligible

Relative Risk Calculations: cough +cough -total Bldg X ref total /239 (26.8%) of respondents have weekly cough 6/206 (2.9%) of reference group have weekly cough Relative Risk = 26.8%/2-9% = 9.2 Confidence Limits:

Results: ExposureBldg XreferenceRR stuffy air74.5%13.1%5.68* dry air53.1%11.7%4.56* dust & dirt56.5%15.0%3.75* odour31.0%8.3%3.75* temp variations38.1%16.0%2.38* lighting23.8%10.2%2.34* Relative Risk Ratios (RR) which are statistically significant are marked with an asterisk (*) and bolded

Results: ExposureBldg XreferenceRR low temp25.5%13.1%1.95* high temp19.7%10.2%1.93* draft16.3%10.7%1.53 second-hand smoke7.5%5.3%1.41 static electricity12.6%10.2%1.23 noise21.3%19.9%1.07 Relative Risk Ratios (RR) which are statistically significant are marked with an asterisk (*) and bolded

Results: Weekly Symptoms Bldg XReferenceRR other symptoms18.4%1.0%18.96* cough26.8%2.9%9.19* scalp & ears17.2%1.9%8.83* hoarse dry throat39.3%4.9%8.10* nausea17.2%2.9%5.89* difficulty conc.22.6%4.9%4.65* heavy-headed40.6%10.7%3.80* Relative Risk Ratios (RR) which are statistically significant are marked with an asterisk (*) and bolded

Results: Weekly Symptoms Bldg XReferenceRR nasal symptoms43.1%11.7%3.70* facial skin18.0%5.8%3.09* fatigue61.9%22.8%2.71* eye irritation33.5%12.6%2.65* headache47.7%18.9%2.52* hand skin irritation20.9%9.2%2.27* Relative Risk Ratios (RR) which are statistically significant are marked with an asterisk (*) and bolded

Results: Work Conditions (Stressors): freqRR interesting work 68.5%1.27* too much work17.9%0.79 influence over working cond45.1%0.82* help from co-workers34.2%1.01 (expected based on OHCOW IAQ investigations)

Results: Personal Health Conditions: freq expectedRR asthma21.2%12%1.76* hayfever27.8%29%0.96 eczema13.9%17%0.82 family history54.2%56%0.97 (expected based on OHCOW IAQ investigations)

Asthma Screening Questions Asthma Screening Questions: number of questions answered positively (80 respondents did not have any positive answers)

Asthma Screening Questions: 50 (21%, ref 12%) of the respondents reported ever having asthmatic problems 94 (39%) respondents answered 3 or more of the asthma screening questions positively 60 of those 94 did not report ever having had asthmatic problems and therefore, might benefit from medical follow-up (the other 34 of the 94 had already been diagnosed) 42 (70%) of these 60 requested follow-up from OHCOW

Findings: Findings: Asthma Screening: - asthma rate 76% higher than expected - recommend medical follow-up for 60 others - 42 (70%) of these 60 requested follow-up from OHCOW

Due to the asthma results, this building fits into the BRI category (this should be reversible):

Survey Comments: 76 (32%) of the respondents provided written comments asthma and allergy problems were the most commonly reported comments: –recent new onset –exacerbation of pre-existing –gradual onset since working in building

SBS Case Definition: NIOSH investigators (App Occ Environ Hyg J 11: (1996)) devised a “Sick Building Syndrome” (SBS) case definition: 3 or more of the following symptoms on a weekly basis (improving away from work): dry or irritated eyes sore or dry throat stuffy or runny nose unusual tiredness or fatigue headache

“SBS” Cases: overall there were 98 respondents (41%) who reported symptoms which fit the MM IAQ survey case definition of the NIOSH SBS case definition (32%, if one includes the restriction that the symptoms must clear up away from the workplace) NIOSH investigators found an average of 18% of respondents fit the SBS case definition in buildings they were asked to investigate due to IAQ concerns

Summary of Findings: 1.Large number of symptomatic occupants; those screening positive for asthma symptoms warrant medical follow-up. 2.Much higher prevalence of symptoms than in “healthy buildings”; also worse than average NIOSH problematic building. 3.Basement the worst, 3rd & 4th floors also significant for upper respiratory irritation.

Health Implications: Symptoms and health conditions (asthma & allergy) seem to be getting worse. Symptomatic occupants should have their allergy and asthma symptoms assessed. If conditions continue as they have been, some health conditions may become chronic (e.g. asthma). The way this situation is being managed could have an effect on the prognosis of building- related conditions.

Follow-up Suggestions: Repeat survey in one year. Follow-up for those who screened positively for asthma Review graphs to answer specific questions (e.g. where are the odour & cough problems most prevalent?). Compare findings with other findings from IAQ reports, HVAC evaluations and mould identification/remediation work.

References 1.“Questionnaire as an Instrument when Evaluating Indoor Climate: Healthy Buildings ’88, Vol. 3, p (1988). 2.“Carbon Dioxide, Particulates & Subjective Human Responses in Office Buildings Without Histories of Indoor Air Quality Problems”. Appl Occup Environ Hyg J. Vol. 7: (192). 3.“Respiratory Symptoms Questionnaire for Asthma Epidemiology: Validity & Reproducibility”, Thorax. Vol 48: (1993).

Acknowledgements Andrew King, Executive Director OHCOW (Toronto) Ken Burgess, Physician OHCOW (Hamilton)