Changes in exhaled nitric oxide concentrations with exposure by group
| Exposure | n | Exhaled nitric oxide concentration (ppb) | ||||||
|---|---|---|---|---|---|---|---|---|
| Pre | Post | Mean difference | (95% CI) | Late | Mean difference | (95% CI) | ||
| *p=0.003; **p=0.02. | ||||||||
| Asthma | ||||||||
| Air | 12 | 7.65 | 7.65 | 0.00 | (−0.89 to 0.89) | 7.71 | 0.06 | (−1.19 to 1.31) |
| Sulphur dioxide 200 ppb | 8 | 7.69 | 8.51 | 0.82 | (−0.09 to 1.72) | 6.9 | −0.79 | (−1.78 to 0.20) |
| Sulphuric acid 200 μg/m3 | 9 | 6.78 | 6.27 | −0.51 | (−1.12 to 0.10) | 7.12 | 0.34 | (−0.82 to 1.51) |
| Sulphuric acid 2000 μg/m3 | 9 | 8.88 | 9.31 | 0.44 | (−0.32 to 1.19) | 8.58 | −0.30 | (−1.46 to 0.86) |
| Ammonium bisulphate 200 μg/m3 | 10 | 8.49 | 10.00 | 1.51 | (0.77 to 2.25)* | 8.28 | −0.21 | (−0.94 to 0.52) |
| Ammonium bisulphate 2000 μg/m3 | 11 | 8.08 | 9.47 | 1.39 | (0.36 to 2.43)** | 7.31 | −0.77 | (−1.92 to 0.37) |
| Normal | ||||||||
| Air | 8 | 3.79 | 3.36 | −0.43 | (−1.24 to 0.39) | 3.04 | −0.75 | (−1.67 to 0.17) |
| Sulphur dioxide 200 ppb | 6 | 3.43 | 3.10 | −0.33 | (−1.26 to 0.61) | 3.56 | 0.14 | (−1.12 to 1.40) |
| Sulphuric acid 200 μg/m3 | 8 | 3.43 | 3.30 | −0.13 | (−0.75 to 0.50) | 2.91 | −0.05 | (−1.22 to 0.19) |
| Sulphuric acid 2000 μg/m3 | 5 | 3.38 | 3.76 | 0.38 | (−0.29 to 1.05) | 3.6 | 0.22 | (−0.43 to 0.87) |
| Ammonium bisulphate 200 μg/m3 | 8 | 4.25 | 4.66 | 0.41 | (−0.33 to 1.16) | 3.75 | −0.50 | (−1.49 to 0.49) |
| Ammonium bisulphate 2000 μg/m3 | 11 | 3.60 | 3.99 | 0.39 | (−0.13 to 0.91) | 3.55 | −0.05 | (−0.79 to 0.70) |