Table 2

Baseline and hourly levels of metal PM2.5 (mg/m3), acceleration (AC) and deceleration (DC) capacities of the heart (ms)

Baseline
Mean (SD)
Hourly average
Mean (SD)*
Hourly average minus baseline
Mean
p Value
Exposure
 PM2.5 (mg/m3)†0.04 (0.3)0.50 (0.4)0.46<0.01
Outcome
 AC (ms)‡–7.1 (3.8)−6.3 (3.1)0.80.25
 DC (ms)8.8 (3.4)7.8 (3.8)−1.00.17
  • Bold values indicate significant associations (p<0.05).

  • *This represents the mean of the hourly averages (hours 1, 2 and 3) from the onset of welding.

  • †PM2.5 ambient levels before shift and average hourly levels during work shift are reported as baseline and hourly average, respectively.

  • ‡AC is measured on a negative scale. N=48 participants.