Table 5 Comparison of factors affecting exposure levels in the underestimation and overestimation groups
From: Misclassification and characterization of exposure to humidifier disinfectants using a questionnaire
Variables | Overestimation group | Underestimation group | Others (true-assumed group) | |||
|---|---|---|---|---|---|---|
Mean | S.D. | Mean | S.D. | Mean | S.D. | |
Period (month) | 69.8 | 40.1 | 15.4 | 14.3 | 25.0 | 21.6 |
Amount of use (mL) | 27.5 | 32.2 | 14.8 | 8.7 | 14.6 | 12.2 |
Daily usage time (hr) | 18.4 | 5.8 | 12.8 | 5.1 | 12.2 | 5.7 |
Usage time for sleeping (hr) | 9.0 | 3.3 | 7.7 | 1.7 | 7.8 | 3.2 |
Indoor concentration (μg/m3) | 1914.1 | 2401.2 | 771.6 | 665.5 | 647.0 | 690.7 |
Cumulative exposure time (hr) | 34,548.6 | 22,997.0 | 5191.7 | 5667.3 | 7702.4 | 8185.3 |
Exposure level (μg/m3·hr) | 49,483,924 | 74,191,015 | 3,552,275 | 3,657,695 | 4,473,117 | 5,260,741 |