Association between exposure to air pollution and cumulative lifetime indicators of asthma and allergy status symptoms at 4 yrs of age for full cohort members with estimated exposures and completed yr-4 questionnaire, based on early-life risk factors
| OR (95% CI) | ||||
| Unadjusted | Subjects n | Adjusted# | Subjects n | |
| Wheeze-ever | ||||
| PM2.5 | 1.15 (1.02–1.31)* | 3524 | 1.22 (1.06–1.41)* | 2575 |
| Soot | 1.13 (1.02–1.26)* | 3524 | 1.18 (1.04–1.34)* | 2575 |
| NO2 | 1.11 (1.00–1.23)* | 3524 | 1.19 (1.05–1.34)* | 2575 |
| Doctor-diagnosed asthma ever | ||||
| PM2.5 | 1.17 (0.95–1.45) | 3528 | 1.32 (1.04–1.69)* | 2575 |
| Soot | 1.16 (0.96–1.39) | 3528 | 1.26 (1.02–1.56)* | 2575 |
| NO2 | 1.16 (0.98–1.38) | 3528 | 1.28 (1.04–1.56)* | 2575 |
| Probable asthma | ||||
| PM2.5 | 1.18 (1.01–1.38)* | 3543 | 1.08 (0.90–1.30) | 2588 |
| Soot | 1.16 (1.01–1.33)* | 3543 | 1.06 (0.90–1.24) | 2588 |
| NO2 | 1.12 (0.98–1.27) | 3543 | 1.04 (0.89–1.22) | 2588 |
| Early wheeze | ||||
| PM2.5 | 1.05 (0.92–1.19) | 3863 | 1.16 (1.00–1.34)* | 2588 |
| Soot | 1.02 (0.91–1.14) | 3863 | 1.11 (0.97–1.26) | 2588 |
| NO2 | 1.03 (0.93–1.15) | 3863 | 1.13 (1.00–1.28)* | 2588 |
| Persistent wheeze | ||||
| PM2.5 | 1.19 (0.99–1.43) | 3863 | 1.19 (0.96–1.48) | 2588 |
| Soot | 1.17 (1.00–1.38)* | 3863 | 1.18 (0.98–1.42) | 2588 |
| NO2 | 1.10 (0.94–1.28) | 3863 | 1.13 (0.94–1.35) | 2588 |
| Early frequent wheeze | ||||
| PM2.5 | 1.15 (0.96–1.39) | 3863 | 1.19 (0.96–1.47) | 2588 |
| Soot | 1.12 (0.95–1.31) | 3863 | 1.14 (0.95–1.37) | 2588 |
| NO2 | 1.09 (0.94–1.27) | 3863 | 1.14 (0.95–1.36) | 2588 |
| Doctor-diagnosed bronchitis ever | ||||
| PM2.5 | 0.99 (0.86–1.14) | 3475 | 0.96 (0.81–1.13) | 2543 |
| Soot | 0.99 (0.87–1.12) | 3475 | 0.95 (0.82–1.10) | 2543 |
| NO2 | 0.96 (0.85–1.08) | 3475 | 0.94 (0.82–1.08) | 2543 |
| Itchy rash/eczema | ||||
| PM2.5 | 1.04 (0.93–1.16) | 3864 | 0.99 (0.88–1.13) | 2588 |
| Soot | 1.03 (0.94–1.14) | 3864 | 0.99 (0.89–1.11) | 2588 |
| NO2 | 1.01 (0.93–1.11) | 3864 | 0.98 (0.88–1.09) | 2588 |
| Doctor-diagnosed eczema ever | ||||
| PM2.5 | 1.10 (0.97–1.25) | 3464 | 0.98 (0.85–1.13) | 2536 |
| Soot | 1.09 (0.98–1.22) | 3464 | 0.99 (0.87–1.12) | 2536 |
| NO2 | 1.06 (0.95–1.17) | 3464 | 0.97 (0.86–1.10) | 2536 |
OR: odds ratio; CI: confidence interval; PM2.5: particles with a 50% cut-off aerodynamic diameter of 2.5 μm; NO2: nitrogen dioxide. #: Adjusted for confounders listed in table 3⇑ from earliest year available (instead of at 4 yrs) i.e. smoking in the home, gas stove, unvented gas water heater, any other siblings and any mould or pets in home and mothers' age at time of birth but not region. ORs are calculated for an interquartile range increase in annual average concentration at birth address. *: Siginificant association, p<0.05.