Table 9. Associations between measured environmental factors and remission of weekly symptoms during the two-year follow-up from 2010 to 2012 (N = 1283).
Type of exposures | Any skin symptoms (OR 95% CI) | Any mucosal symptoms (OR 95% CI) | Any general symptoms (OR 95% CI) | Any symptoms improved if away from school (OR 95% CI) | Any school related mucosal symptoms (OR 95% CI) | Any school related general symptoms (OR 95% CI) |
Indoor climate and air pollutants in classrooms | ||||||
SO2 | 1.02(0.99–1.04) | 0.80(0.27–2.35) | 1.34(0.39–4.58) | 1.14(0.27–4.74) | 0.96(0.77–1.20) | 0.98(0.78–1.25) |
NO2 | 1.02(0.93–1.12) | 0.97(0.66–1.42) | 0.95(0.62–1.45) | 0.84(0.49–1.46) | 0.91(0.39–2.12) | 0.69(0.29–1.63) |
O3 | 0.97(0.92–1.03) | 0.97(0.74–1.29) | 0.96(0.71–1.29) | 1.24(0.88–1.74) | 1.22(1.71–2.10) | 0.86(0.53–1.41) |
PM10 | 1.43(0.59–3.49) | 0.71(0.54–0.93)* | 0.82(0.63–1.08) | 0.59(0.44–0.81)** | 0.52(0.31–0.88)* | 0.62(0.40–0.97)* |
Temperature | 0.69(0.42–1.14) | 0.79(0.14–4.35) | 1.00(0.82–1.22) | 0.96(0.77–1.20) | 0.75(0.52–1.08) | 1.16(0.78–1.72) |
CO2 | 0.51(0.13–2.05) | 0.72(0.46–1.14) | 1.02(0.62–1.66) | 0.60(0.37–0.99)* | 1.07(0.43–2.69) | 1.26(0.49–3.22) |
RH | 0.92(0.35–2.40) | 0.81(0.58–1.13) | 1.02(0.72–1.45) | 0.60(0.42–0.85)** | 0.93(0.48–1.79) | 0.99(0.53–1.86) |
Air pollutants outside the school | ||||||
SO2 | 1.01(0.99–1.04) | 0.38(0.20–0.74)** | 0.82(0.39–1.69) | 0.80(0.34–1.91) | 0.89(0.78–1.05) | 0.93(0.81–1.07) |
NO2 | 1.05(0.87–1.29) | 0.50(0.24–1.04) | 0.79(0.36–1.74) | 0.37(0.15–0.89)* | 0.91(0.79–1.04) | 0.89(0.78–1.02) |
O3 | 0.88(0.76–1.03) | 0.80(0.41–1.54) | 0.72(0.34–1.54) | 0.90(0.37–2.18) | 0.65(0.16–2.62) | 1.03(0.88–1.20) |
PM10 | 0.81(0.34–1.95) | 0.83(0.68–1.01) | 0.93(0.79–1.09) | 0.72(0.60–0.85)*** | 0.78(0.58–1.04) | 0.86(0.67–1.11) |
Odds ratio (OR) with 95% confidence interval (CI) calculated by multiple logistic regression. Adjustment for age, gender and parental asthma or allergy, analysing each indoor climate variable separately.
*P<0.05.
**P<0.01.
***P<0.001.