Table 3

Incidence rate (IR) of hospital-diagnosed lower respiratory tract infections during the first 2 years of life by quartiles (Q) of the mean air pollutant exposures during pregnancy and in the first year of life, Espoo Cohort Study

ExposuresnPrenatal exposureFirst-year exposure
IR (95% CI)nIR (95% CI)
PM2.5
 Q1171.36 (0.79 to 2.18)141.11 (0.60 to 1.86)
 Q2292.29 (1.53 to 3.28)181.42 (0.84 to 2.25)
 Q3201.57 (0.96 to 2.42)241.90 (1.21 to 2.82)
 Q4221.74 (1.09 to 2.64)322.53 (1.73 to 3.57)
PM10
 Q1201.57 (0.96 to 2.42)151.18 (0.66 to 1.95)
 Q2262.04 (1.33 to 2.99)171.34 (0.78 to 2.15)
 Q3211.68 (1.04 to 2.56)251.97 (1.28 to 2.92)
 Q4211.68 (1.04 to 2.57)312.45 (1.66 to 3.48)
NO2
 Q1201.61 (0.98 to 2.48)191.50 (0.90 to 2.34)
 Q2292.32 (1.55 to 3.33)141.11 (0.60 to 1.86)
 Q3151.15 (0.64 to 1.89)241.90 (1.21 to 2.82)
 Q4241.93 (1.24 to 2.87)312.45 (1.66 to 3.48)
CO
 Q1221.74 (1.09 to 2.64)191.50 (0.90 to 2.34)
 Q2221.74 (1.09 to 2.64)171.34 (0.78 to 2.15)
 Q3201.59 (0.97 to 2.46)241.90 (1.21 to 2.82)
 Q4241.89 (1.21 to 2.82)282.21 (1.47 to 3.20)
SO2
 Q1131.00 (0.53 to 1.71)161.26 (0.72 to 2.05)
 Q2332.65 (1.82 to 3.72)161.27 (0.72 to 2.06)
 Q3211.67 (1.03 to 2.56)191.50 (0.90 to 2.34)
 Q4211.68 (1.04 to 2.57)372.92 (2.06 to 4.03)
O3
 Q1302.39 (1.61 to 3.41)312.45 (1.66 to 3.48)
 Q2211.64 (1.02 to 2.51)262.05 (1.34 to 3.01)
 Q3120.95 (0.49 to 1.65)151.18 (0.66 to 1.95)
 Q4252.01 (1.30 to 2.96)161.26 (0.72 to 2.05)
  • CO, carbon monoxide; IR, Incidence rate per 100 person-years; n, episodes of infections; NO2, nitrogen dioxide; O3, ozone; PM10, particulate matter with a diameter of 10 μm; PM2.5, particulate matter with a diameter of 2.5 μm; SO2, sulfur dioxide.