Table 7. Associations between measured environmental factors and the prevalence of weekly symptoms at baseline in 2010 (N = 2134).
| Type of exposures | Any skinsymptoms(OR 95% CI) | Any mucosalSymptoms(OR 95% CI) | Any generalSymptoms(OR 95% CI) | Any symptomsimproved ifaway fromschool(OR 95% CI) | Any school relatedmucosal symptoms(OR 95% CI) | Any school relatedgeneral symptoms(OR 95% CI) |
| Indoor climate and air pollutants in classrooms | ||||||
| SO2 | 1.02(0.93–1.13) | 0.78(0.48–1.29) | 0.83(0.49–1.40) | 1.83(1.18–2.83)** | 1.28(0.70–2.36) | 1.30(0.69–2.44) |
| NO2 | 0.75(0.53–1.06) | 0.84(0.71–1.01) | 0.86(0.72–1.04) | 1.14(0.97–1.34) | 1.02(0.81–1.27) | 0.93(0.74–1.17) |
| O3 | 1.46(1.16–1.83)*** | 1.02(0.88–1.19) | 1.10(0.94–1.28) | 1.09(0.95–1.25) | 1.06(0.88–1.28) | 1.03(0.85–1.25) |
| PM10 | 0.61(0.18–2.26) | 0.95(0.84–1.08) | 2.08(0.55–0.78) | 1.08(0.96–1.20) | 1.11(0.96–1.30) | 1.15(0.98–1.34) |
| Temperature | 1.15(0.98–1.34) | 0.57(0.26–1.28) | 1.03(0.45–2.36) | 1.00(0.86–1.17) | 0.46(0.17–1.26) | 1.00(0.36–2.80) |
| CO2 | 0.74(0.47–1.18) | 0.90(0.73–1.10) | 0.97(0.78–1.20) | 1.01(0.85–1.21) | 0.90(0.69–1.16) | 0.79(0.60–1.05) |
| RH | 0.72(0.50–1.02) | 0.92(0.79–1.07) | 0.96(0.82–1.12) | 1.05(0.92–1.19) | 0.98(0.81–1.19) | 0.94(0.77–1.15) |
| Air pollutants outside the school | ||||||
| SO2 | 1.16(0.72–1.87) | 1.08(0.85–1.37) | 1.21(0.95–1.55) | 1.25(1.02–1.55)* | 1.16(0.86–1.56) | 1.30(0.96–1.77) |
| NO2 | 0.29(0.13–0.62)** | 0.87(0.61–1.24) | 0.91(0.63–1.32) | 1.21(0.87–1.66) | 0.97(0.63–1.51) | 0.89(0.56–1.40) |
| O3 | 0.82(0.46–1.44) | 0.77(0.58–1.03) | 1.04(0.77–1.41) | 0.96(0.74–1.24) | 0.88(0.64–1.20) | 0.91(0.66–1.26) |
| PM10 | 0.62(0.27–1.43) | 0.97(0.91–1.04) | 1.92(0.87–4.24) | 1.40(0.69–2.82) | 1.05(0.97–1.14) | 1.08(0.99–1.17) |
Odds ratio (OR) with 95% confidence interval (CI) calculated by multiple logistic regression. Adjustment for age, gender and parental asthma or allergy, analysing each exposure variable separately.
*P<0.05.
**P<0.01.
***P<0.001.