Average value over the whole two-week exposure period.
b Floor material in living room: W e wooden flooring, cork or linoleum; P e parquets; C e carpet.
c Experimental period: W e Winter (NovembereFebruary), S e Spring (FebruaryeMay).
d Average value over two-week exposure period.
e Average value over 24-h measurement. Measurement in dwelling no 3. was terminated and excluded from analyses.
f Missing data due to failure of measuring device.