Table 4

Associations between groups of combined exposure based on maximum daily levels of grass pollen and air pollution exposure in the previous 4 days and respiratory indices in the PARIS birth cohort: multivariable analysis

Grass pollen >10 grains/m3 Poor air quality*FEV1 (mL) n=973FVC (mL) n=973
aβ (95% CI)aβ (95% CI)
Group 1NoNoReferenceReference
Group 2NoYes7.7 (−20.9 to 36.3)8.3 (−26.1 to 42.6)
Group 3YesNo−19.9 (−55.7 to 15.9)−41.0 (−84.1 to 2.1)
Group 4YesYes−70.2 (−129.7 to −10.7)−92.5 (−164.1 to −20.9)
Grass pollen >10 grains/m3 Poor air quality*FEV1/FVC (%) n=973FeNO>20 ppb n=866
aβ (95% CI)n/NaOR (95% CI)
Group 1NoNoReference86/446Reference
Group 2NoYes−0.1 (−1.0 to 0.7)55/2271.38 (0.90 to 2.11)
Group 3YesNo0.8 (−0.3 to 1.8)26/1530.70 (0.40 to 1.24)
Group 4YesYes0.9 (−0.9 to 2.6)8/400.81 (0.33 to 2.03)
  • All models were adjusted for sex, age and height at the health check-up, ethnicity, family SES, exposure to environmental tobacco smoke at home at 8 years of age, current asthma and average ambient temperature and relative humidity the day before the health check-up. The estimates in bold differ significantly from the reference (p<0.05). Total N for each model may vary due to missing information.

  • *Poor air quality was defined as an air quality index ATMO ≥6 (on a scale of 1 to 10) based on the daily average air concentrations of PM10, NO2, O3 and SO2.

  • aβ, adjusted regression coefficient; aOR, adjusted OR; FeNO, fraction of exhaled nitric oxide; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; NO2, nitrogen dioxide; O3, ozone; PM10, particulate matter with aerodynamic diameter <10 µm; SO2, sulphur dioxide.