Table 2.
Distributions of concentration and load of microbial agents in floor and chair dust.
| Concentration (per g or mg)a |
Load (per m2 floor or per chair)b |
||||
|---|---|---|---|---|---|
| Sample type, microbial agent analyzed | < LODc (n/total) | GM (GSD) | IQR | GM (GSD) | IQR |
| Floor dust | |||||
| Total fungi (CFU) | 3/328 | 7,700 (4.7) | 14,300 | 2,000 (5.5) | 4,700 |
| Fungi with Aw ≥ 0.8 | 12/328 | 4,800 (5.6) | 11,100 | 1,300 (6.6) | 3,900 |
| Hydrophilic fungi | 53/328 | 2,600 (7.0) | 7,700 | 700 (7.9) | 2,600 |
| Yeasts only | 78/328 | 1,700 (6.7) | 5,600 | 500 (8.1) | 1,600 |
| Hydrophilic (no yeasts) | 233/328 | 380 (4.2) | 170 | 100 (4.5) | 110 |
| Ergosterol (ng) | 0/334 | 0.5 (3.1) | 0.7 | 126.2 (3.9) | 231.8 |
| Endotoxin (EU) | 0/338 | 10.9 (4.1) | 28.1 | 2683.0 (4.8) | 7413.6 |
| Cat allergen (μg) | 3/314 | 2.5 (2.4) | 2.3 | 0.7 (2.9) | 0.9 |
| Dog allergen (μg) | 16/314 | 2.1 (2.8) | 2.6 | 0.6 (3.2) | 1.0 |
| Chair dust | |||||
| Total fungi (CFU) | 1/326 | 11,000 (5.4) | 31,200 | 4,900 (5.7) | 12,000 |
| Fungi with Aw ≥ 0.8 | 8/326 | 7,000 (6.2) | 15,700 | 3,100 (6.6) | 7,400 |
| Hydrophilic fungi | 56/326 | 2,600 (8.1) | 7,000 | 1,200 (8.5) | 3,800 |
| Yeasts only | 118/326 | 1,100 (6.5) | 3,400 | 500 (7.0) | 1,300 |
| Hydrophilic (no yeasts) | 181/326 | 610 (6.7) | 600 | 270 (7.1) | 330 |
| Ergosterol (ng) | 0/325 | 0.4 (2.5) | 0.5 | 173.6 (2.9) | 260.4 |
| Endotoxin (EU) | 0/327 | 2.1 (2.6) | 2.7 | 932.8 (3.0) | 1268.8 |
| Cat allergen (μg) | 0/318 | 12.5 (3.6) | 24.8 | 5.8 (4.1) | 9.8 |
| Dog allergen (μg) | 4/318 | 5.7 (3.7) | 12.2 | 2.6 (4.1) | 6.5 |
a
Units are ng/mg for ergosterol, EU/mg for endotoxin, CFU/g for fungi, and μg/g for allergens.
b
Computed by multiplying the concentration of the microbial agents by the total amount of dust collected in each floor (or chair) sample and then dividing by 2 m2 for floor samples.
c
LODs are 0.002 EU/mg for endotoxin, 350–400 CFU/g for total culturable fungi depending on the amount of samples analyzed, 0.5 μg/g for cat allergen, and 0.4 μg/g for dog allergen. For samples < LOD, we used LOD/2 for total fungi and 200 CFU/g for the subgroups of total culturable fungi.