Table 4.
Associations of microbial agents in floor and chair dust with respiratory, epi-asthma, or current postoccupancy asthma cases in single environmental variable models adjusted for age, sex, race, smoking status, and building occupancy time.
| OR (95% CI) for different outcome models
|
||||||
|---|---|---|---|---|---|---|
| Respiratory
|
Epi-asthma
|
Postoccupancy asthma
|
||||
| Environmental variable | Floor dust | Chair dust | Floor dust | Chair dust | Floor dust | Chair dust |
| Total culturable fungi | 1.66** (1.19–2.33) | 1.37** (1.02–1.85) | 1.72** (1.21–2.46) | 1.58** (1.13–2.20) | 1.56* (0.96–2.53) | 1.67** (1.07–2.60) |
| Aw ≥ 0.8 fungia | 1.66** (1.17–2.38) | 1.31** (1.00–1.72) | 1.69** (1.15–2.47) | 1.46** (1.09–1.97) | 1.72** (1.03–2.88) | 1.56** (1.05–2.30) |
| Fungi not classified as Aw ≥ 0.8 fungi | 1.11 (0.80–1.54) | 1.09 (0.76–1.56) | 1.21 (0.84–1.72) | 1.11 (0.75–1.64) | 0.80 (0.47–1.37) | 1.20 (0.67–2.18) |
| Hydrophilic fungi | 1.73** (1.20–2.51) | 1.45** (1.07–1.97) | 1.80** (1.20–2.69) | 1.63** (1.16–2.28) | 2.19** (1.23–3.89) | 1.85** (1.19–2.89) |
| Fungi not classified as hydrophilic | 1.08 (0.79–1.50) | 1.25* (0.96–1.62) | 1.12 (0.79–1.59) | 1.31* (0.99–1.74) | 0.71 (0.42–1.19) | 1.31 (0.88–1.96) |
| Yeasts only | 1.37* (0.97–1.93) | 1.46** (1.06–2.01) | 1.46* (1.00–2.13) | 1.42** (1.01–1.99) | 1.77** (1.05–3.01) | 1.55* (1.00–2.41) |
| Hydrophilic fungi without yeasts | 1.50** (1.18–1.91) | 1.21* (0.97–1.51) | 1.47** (1.13–1.91) | 1.36** (1.06–1.74) | 1.43* (0.99–2.05) | 1.44** (1.05–1.98) |
| Ergosterol | 1.56** (1.13–2.16) | 1.38* (0.98–1.93) | 1.60** (1.13–2.28) | 1.54** (1.05–2.26) | 1.37 (0.87–2.17) | 1.63* (0.95–2.81) |
| Endotoxin | 1.60** (1.09–2.37) | 1.10 (0.82–1.48) | 1.54** (1.01–2.34) | 1.09 (0.79–1.52) | 1.40 (0.79–2.50) | 1.15 (0.71–1.87) |
| Cat allergen (Fel d 1) | 1.33* (0.96–1.83) | 1.21 (0.91–1.63) | 1.35* (0.95–1.92) | 1.37* (1.00–1.88) | 1.16 (0.72–1.88) | 1.55* (1.00–2.39) |
| Dog allergen (Can f 1) | 1.18 (0.85–1.65) | 1.26 (0.86–1.83) | 1.09 (0.76–1.57) | 1.20 (0.78–1.83) | 1.01 (0.62–1.65) | 1.10 (0.61–2.00) |
ORs and 95% CIs were computed based on change of the IQR in the environmental variable. The number of samples for each model varies from 286 to 303 for respiratory cases, 225 to 241 for epi-asthma cases, and, 170 to 183 for postoccupancy asthma cases. Units of the environmental variables are as follows: CFU/m2 for fungi in floor dust and CFU/chair for fungi in chair dust; EU/m2 for endotoxin in floor dust and EU/chair for endotoxin in chair dust; ng/m2 for ergosterol in floor dust and ng/chair for ergosterol in chair dust; and μg/m2 for allergen in floor dust and μg/chair for allergen in chair dust.
Mesophilic and hydrophilic fungi (Table 3); hydrophilic fungi include yeasts, Phoma herbarum, Chaetomium globosum, Mucor plumbeus, Rhizopus stolonifer, and Stachybotrys chartarum.
Statistically significant at α = 0.1.
Statistically significant at α = 0.05.