Table 1.
Characteristics of lifeguards
| Males (n = 29) | Females (n = 10) | |
|---|---|---|
| Age (yr, mean (sd)) | 35.9 (8.8) | 33.3 (10.0) |
| Height (cm, mean (sd)) | 180.4 (7.6) | 168.3 (7.7) |
| Smokers (n, (%)) | 9 (31) | 4 (40) |
| Former smokers (n, (%)) | 5 (17) | 1 (10) |
| Non-smokers (n, (%) | 15 (52) | 5 (50) |
| FEV1 | ||
| (L, mean (sd)) | 5.09 (0.69) | 3.83 (0.47) |
| (% predicted, mean (sd)) | 121.0 (15.7) | 119.7 (11.3) |
| FVC | ||
| (L, mean (sd)) | 6.34 (0.69) | 4.53 (0.48) |
| (% predicted, mean (sd)) | 124.4 (11.5) | 123.2 (10.9) |
| FEV1/FVC | ||
| (% observed, mean (sd)) | 80.3 (6.1) | 84.4 (4.7) |
| (% predicted, mean (sd)) | 99.5 (8.0) | 102.0 (4.9) |
| Airway responsiveness | ||
| MBC+ (n, (%)) | 11 (37.9) | 4 (40.0) |
| NDRS (mean (sd)) | 0.22 (0.09) | 0.19 (0.09) |
| Personal history of allergy ((n, (%)) | 2 (6.9) | 3 (30.0) |
| Acute work-related symptoms (n, (%)) | ||
| Ocular | 21 (72.4) | 7 (70.0) |
| Nasal | 15 (51.7) | 5 (50.0) |
| Laryngeal | 14 (48.3) | 3 (30.0) |
FEV1: Forced Expiratory Volume in one Second; FVC: Forced Vital Capacity
MBC: Methacholine Bronchial Challenge test
MBC+: decrease of 20% or more below the baseline value of FEV1 in a methacholine bronchial challenge test.
NDRS: Normalized Dose Response Slope