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Table 5 Associations (Β) between peak expiratory flow (PEF) in the morning and evening (PEFmo and PEFev) and exposure to pollen (per 100 grains) and air pollutants in single-, pairwise-, and multi-exposure models with 95% confidence interval (pooled results). Significant results are indicated with bold font

From: Birch pollen, air pollution and their interactive effects on airway symptoms and peak expiratory flow in allergic asthma during pollen season – a panel study in Northern and Southern Sweden

 

Pollen lag 0–2

Pollen lag 0–6

NOx

O3

PM2.5

 

β (95% CI)

95% CI

95% CI

95% CI

95% CI

ΔPEF mo (mL)

  Adjusted for Pollen

-1.10 (-2.86; 0.66)

-1.00 (-3.00; 1.01)

-

-

-

  + NOx

-1.06 (-3.04; 0.92)

-0.97 (-3.20; 1.27)

-0.16 (-3.21; 2.88)

-

-

  + O3

-1.07 (-2.90; 0.76)

-0.97 (-3.05; 1.11)

-

1.54 (-0.92; 4.00)

-

  + PM2.5

-1.10 (-2.67; 0.47)

-1.20 (-3.09; 0.70)

-

-

2.16 (0.23; 4.09)

  + NOx, O3, PM2.5

-1.05 (-2.78;-0.68)

-1.17 (-3.19; 0.86)

-0.43 (-2.48; 1.63)

0.18 (-1.70; 2.06)

2.14 (1.01; 3.26)

ΔPEFev (mL)

  Adjusted for Pollen

-1.24 (-2.45; -0.04)

-1.24 (-3.88; 1.40)

-

-

-

  + NOx

-1.25 (-2.53; 0.03)

-1.26 (-4.01; 1.48)

0.40 (-0.97; 1.77)

-

-

  + O3

-1.22 (-2.48; 0.04)

-1.24 (-3.88; 1.40)

-

0.66 (-1.24; 2.55)

-

  + PM2.5

-0.93 (-1.70; -0.17)

-0.72 (-2.30; 0.86)

-

-

2.88 (-1.80; 7.56)

  + NOx, O3, PM2.5

-0.93 (-1.71; -0.15)

-0.73 (-2.25; 0.80)

0.17 (-1.65; 1.31)

-0.27 (-2.35; 1.81)

3.21 (-1.27; 7.68)

  1. ΔPEF: deviation from each individual’s mean of each season. Exposure at lag 1–2 for PEFmo and lag 0–2 for PEFev
  2. Results from pooled with meta-analysis of mixed model results for pollen (single-exposure), pollen and pairwise combinations of pollen and either NOx, O3 and PM2.5, and multi-exposure models adjusted for pollen. All models were adjusted for relative humidity and temperature, with identification number as a random effect. Associations are reported per 100 grains/m3 for pollen and per city-specific IQR for pollutants (Göteborg: NOx 20.0 µg/ m3, O3 22.9 µg/ m3, PM2.5 3.3 µg/ m3, Umeå: NOx 14.7 µg/m3, O3 24.1 µg/ m3, PM2.5 2.8 µg m3)