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Table 3 Associations between IQR increases in levels of individual pollutants and components of heart rate variability

From: Exposure to air pollution near a steel plant is associated with reduced heart rate variability: a randomised crossover study

    Frequency domain Time domain
Pollutant Pollutant IQR Heart Rate (bpm) HF Power (ms2) LF Power (ms2) HF/LF SDNN
(ms)
RMSSD
(ms)
pNN50
(%)
CO (ppm) 0.30 0.32*
(0.10, 0.54)
-0.39
(-0.89, 0.11)
-3.78*
(-7.41, -0.12)
-0.03
(-0.08, 0.02)
-1.09*
(-2.12, -0.06)
-0.99
(-2.09, 0.11)
-0.38
(-0.80, 0.03)
NO (ppb) 4.40 1.22*
(0.31, 2.14)
-0.56
(-2.61, 1.50)
-1.51*
(-3.01, -0.01)
-0.09
(-0.31, 0.13)
-4.67*
(-8.89, -0.44)
-4.13
(-8.62, 0.35)
-1.77*
(-3.52, -0.02)
NO2 (ppb) 4.30 1.40*
(0.48, 2.32)
-1.101
(-3.17, 0.97)
-1.33
(-2.82, 0.15)
-0.19
(-0.40, 0.03)
-6.41*
(-10.65, -2.17)
-6.02*
(-10.53, -1.52)
-1.17
(-2.94, 0.59)
NOx (ppb) 8.30 1.50*
(0.56, 2.43)
-0.38
(-2.46, 1.71)
-1.46
(-3.00, 0.08)
-0.12
(-0.34, 0.09)
-6.60*
(-10.90, -2.29)
-6.01*
(-10.58, -1.44)
-1.41
(-3.21, 0.38)
O3 (ppb) 8.70 0.30
(-0.66, 1.26)
-2.50*
(-4.67, -0.33)
-2.24
(-17.32, 12.84)
-0.32*
(-0.54, -0.11)
-5.59
(-10.01, 1.18)
-6.11
(-10.87, 1.36)
1.28
(-0.55, 3.10)
SO2 (ppb) 4.60 0.78*
(0.15, 1.41)
-0.82
(-2.24, 0.61)
-1.07*
(-2.13, -0.002)
-0.11
(-0.25, 0.03)
-4.08*
(-7.00, -1.16)
-3.41
(-6.52, -0.31)*
-1.08
(-2.30, 0.13)
PM2.5 (μg/m3) 9.00 0.97
(-0.04, 1.97)
-2.43*
(-4.62, -0.24)
-1.88*
(-3.46, -0.29)
-0.16
(-0.38, 0.07)
-5.34 *
(-9.96, -0.72)
-5.28*
(-10.15, -0.41)
-1.99*
(-3.91, -0.07)
UFP (particles/cm3) 12236 1.10*
(0.04, 2.16)
-1.89
(-4.38, 0.60)
-1.61*
(-3.21, -0.01)
-0.15
(-0.38, 0.08)
-7.13*
(-12.27, -1.98)
-5.03
(-10.63, 0.57)
-2.20*
(-4.24, -0.15)
  1. IQR values for participant specific pollutant exposures, combined for both the Bayview and College sites, are shown in the second column. The amplitude of the change in each HRV parameter associated with an IQR increase in pollutant level and 95% CI (bracketed) are reported for each pollutant/HRV parameter pair. Statistically significant associations (p < 0.05) are denoted by *
  2. * = p < 0.05. Mean temperature throughout the study was 23.4 °C (SD 4.1 °C); mean relative humidity was 56.0% (SD 14.7%)