Table 2.
Baseline characteristics of high-concentration and low-concentration toner-exposure groups
| Parameters (unit) | High-concentration toner exposure group | Low-concentration toner exposure group | P-value | ||
|---|---|---|---|---|---|
| n = 49 | n = 838 | ||||
| M (SD)/% | M (SD)/% | ||||
| Age (years) | 36.8 | (8.3) | 38.8 | (7.0) | 0.100 |
| BMI (kg/m2) | 22.9 | (2.4) | 23.4 | (3.0) | 0.294 |
| Current smoker | 53.1% | 51.1% | 0.883 | ||
| Prevalence of respiratory diseases (%) | |||||
| Asthma | 12.2% | 9.3% | 0.453 | ||
| Allergic rhinitis | 59.2% | 50.6% | 0.303 | ||
| Allergic dermatitis | 26.5% | 20.5% | 0.364 | ||
| Pneumonia | 2.7% | 0.4% | 0.204 | ||
| Sinusitis | 2.0% | 2.7% | 1.00 | ||
| Ratio of workers handling harmful substances (%) | |||||
| Workers handling dust other than toner | 4.1% | 2.9% | 0.650 | ||
| Workers handling organic solvent | 32.7% | 25.9% | 0.317 | ||
| Respiratory function test indicators | |||||
| VC (l) | 4.3 | (0.7) | 4.2 | (0.6) | 0.459 |
| %VC (%) | 93.0 | (10.3) | 92.4 | (10.7) | 0.695 |
| FEV1 (l) | 3.5 | (0.5) | 3.5 | (0.5) | 0.345 |
| %FEV1 (%) | 95.1 | (10.3) | 95.0 | (11.2) | 0.935 |
| FEV1/FVC (%) | 83.6 | (5.8) | 83.0 | (5.9) | 0.491 |
| %FEV1/FVC (%) | 100.1 | (6.7) | 100.1 | (6.9) | 0.975 |
| V25 (l/s) | 1.7 | (0.5) | 1.6 | (0.5) | 0.244 |
| %V25 (%) | 71.2 | (19.7) | 68.1 | (19.9) | 0.481 |
| Biomarkers | |||||
| CRP (mg/dl) | 0.07 | (0.11) | 0.09 | (0.19) | 0.322 |
| IgE (IU/ml) | 198.2 | (274.4) | 201.9 | (386.4) | 0.953 |
| IL-4 (pg/ml) | 19.1 | (19.2) | 19.2 | (29.9) | 0.981 |
| IL-6 (pg/ml) | 1.15 | (0.86) | 1.37 | (3.25) | 0.674 |
| IL-8 (pg/ml) | 3.78 | (17.85) | 2.85 | (20.07) | 0.773 |
| IFN-γ (IU/ml) | 0.08 | (0.07) | 0.11 | (0.13) | < 0.001 |
| 8-OHdG/Creatinine (ng/mg) | 3.98 | (1.64) | 3.80 | (1.52) | 0.738 |
M mean, SD standard deviation, BMI body mass index, VC vital capacity, %VC percentage of VC to predicted VC value, FEV1 forced expiratory volume in 1 s, %FEV1 percentage of FEV1 to predicted FEV1 value, FEV1/FVC percentage of forced expiratory volume in 1 s, %FEV1/FVC percentage of FEV1/FVC to predicted FEV1/FVC value, V25 maximal expiratory flow at 25% forced VC, CRP C-reactive protein, IgE immunoglobulin E, IL interleukin, IFN-γ interferon-gamma, 8-OHdG 8-hydroxy-2′-deoxyguanosine