Table 5

Main effect of PM2.5 (mg/m3) on acceleration capacity (AC; ms) and deceleration capacity (DC; ms) with adjustment for hourly pre-exposures from the linear mixed effect response-lagged models with 36 participants who had not welded 2 weeks before the study

Parameter(95% CI)(95% CI)
 No lag1.54 (0.96 to 2.32)−1.18 (−0.60 to −1.79)
 1 h lag†0.97 (0.13 to 1.81)−0.89 (−0.09 to −1.70)
 2 h lag†0.66 (−0.94 to 1.87)−0.37 (1.09 to −1.83)
 3 h lag†0.29 (−2.58 to 2.60)−0.18 (2.57 to −2.15)
  • Bold values indicate significant associations (p<0.05). Models are adjusted for age, smoking status, actively smoking, secondhand smoke exposure, time of day and season of ECG reading, and baseline AC or DC.

  • *AC is measured on a negative scale; therefore, a 1 mg/m3 increase in PM2.5 results in a decrease in AC by 1.54 ms (on a negative scale) for the association without any lag.

  • †Lagged models adjust for exposure time points before the lags. For example, a 1 hour lag model also adjusts for PM2.5 measurements in the preceding hour before the exposure time point of interest.