Ventilation parameters recorded during exposures, by group
| Group | Exposure | |||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Air | Sulphur dioxide 200 ppb | Sulphuric acid | Ammonium bisulphate | |||||||||||||||
| 200 μg/m3 | 2000 μg/m3 | 200 μg/m3 | 2000 μg/m3 | |||||||||||||||
| Breath count/hour | Vol (l) | Breath count/hour | Vol (l) | Breath count/hour | Vol (l) | Breath count/hour | Vol (l) | Breath count/hour | Vol (l) | Breath count/hour | Vol (l) | |||||||
| Total | Oral | Total | Total | Oral | Total | Total | Oral | Total | Total | Oral | Total | Total | Oral | Total | Total | Oral | Total | |
| All exposures were of an hour’s duration. | ||||||||||||||||||
| Breath count and volume (litres) data are group means with 95% confidence intervals in parentheses. | ||||||||||||||||||
| Significance testing by paired t tests. | ||||||||||||||||||
| Normal | 916.0 | 7.4 | 345.1 | 882.3 | 7.4 | 355.9 | 915.0 | 6.3 | 421.8 | 941.2 | 7.1 | 328.4 | 916.9 | 9.1 | 317.2 | 954.9 | 8.7 | 401.7 |
| (832 to 1000) | (5.5 to 9.3) | (276 to 414) | (765 to 999) | (5.7 to 9.1) | (244 to 467) | (853 to 977) | (5.0 to 7.4) | (264 to 579) | (827 to 1010) | (5.8 to 8.3) | (269 to 388) | (852 to 982) | (7.6 to 10.6) | (272 to 362) | (888 to 1022) | (7.3 to 10.0) | (296 to 507) | |
| Asthma | 906.8 | 7.5 | 311.4 | 958.9 | 7.8 | 318.8 | 943.5 | 6.8 | 330.0 | 896.2 | 7.9 | 306.3 | 931.0 | 6.9 | 359.6 | 941.8 | 8.2 | 329.7 |
| (809 to 1004) | (6.2 to 8.8) | (268 to 355) | (855 to 1063) | (6.4 to 9.3) | (273 to 364) | (831 to 1055) | (5.2 to 8.3) | (283 to 376) | (792 to 896) | (6.4 to 9.5) | (259 to 353) | (830 to 1032) | (5.4 to 8.4) | (309 to 409) | (854 to 1030) | (7.1 to 9.2) | (286 to 373) | |
| p=0.04 | ||||||||||||||||||