Subjective Indoor Air Quality in Geriatric Hospitals

Abstract

This investigation studied subjective indoor air quality (IAQ) in hospitals in relation to building dampness and the type of construction. Building dampness is known to be an important contributor to perception of the indoor environment. Dampness in floor construction is known to cause chemical degradation of polyvinyl chloride floor coatings, but few epidemiological studies on this topic have been published. Another topic of interest is the dif ferent IAQ in buildings constructed with different build ing materials and to different architectural designs. We looked at four geriatric hospital buildings of different age and design chosen without regard to the level of com plaints. The first was built in 1925 and redecorated in 1955. The second, built in 1985, had known dampness in the floor construction. The other two, built in 1993 and 1995, were constructed to conventional and 'alternative' building designs, respectively. Eighty-eight, from a total of 95 staff, answered a questionnaire on subjective IAQ. Indoor measurements of room temperature, relative air humidity, air flow rate, illumination, moulds, bacteria, formaldehyde and other volatile compounds, respirable dust, carbon monoxide, carbon dioxide, nitrogen dioxide and ozone were performed in all buildings. Statistical analysis was performed by multiple logistic regression, adjusting for a possible influence of building age, age of the subjects, gender, tobacco smoke and atopy. Damp ness in the upper concrete floor surface (75-84%), am monia under the floor (3 ppm), and 2-ethyl-1-hexanol in the air were detected in the two buildings built in 1985 and 1993. Complaints on air dryness and stuffy air were significantly commoner in these damp buildings. The subjects in the buildings constructed to an 'alternative' design had significantly fewer complaints about stuffy air, dry air and static electricity as compared to the other buildings. The average room temperature was similar (22.0-23.0°C) in all buildings. All buildings had low lev els of formaldehyde, moulds and bacteria. In conclusion, building dampness in the floor construction may in crease the sensation of air dryness and stuffy air. In con trast, the high proportion of satisfied inhabitants in the alternative-design building shows that it is possible to construct a new building with good subjective IAQ.