| N | Mean (SD) or Percent | Range |
---|---|---|---|
Cohort characteristics | |||
Age (years)a | 34 | 36.0 (12.0) | 21.3-61.0 |
Males | 38 | 100% | Â |
Race | Â | Â | Â |
 Caucasian | 31 | 83.3% |  |
 African-American | 5 | 11.1% |  |
 Hispanic | 2 | 5.6% |  |
Current smoker | |||
 Yes | 12 | 30.6% |  |
 No | 26 | 69.4% |  |
Years worked as boilermakerb | 36 | 6.8 (9.4) | 1 - 35 |
Exposure characteristics c | |||
 |  | Median (IQR) or Percent | |
PM2.5 exposure (mg/m3)c | 54 | 0.52 (1.34) | 0.02-3.41 |
Weld day samplesd | Â | Â | Â |
 Yes | 44 | 81.5% |  |
 No | 10 | 18.5% |  |
Used respirator | Â | Â | Â |
 Yes | 13 | 24.1% |  |
 No | 41 | 75.9% |  |