Characteristics of participants
| Characteristics | Mean | SD |
| Age (years) | 41.7 | 13.3 |
| BMI (kg/m2) | 29.4 | 6.6 |
| PM2.5_welding (μg/m3) | 421 | 360 |
| PM2.5_classroom area (μg/m3) | 120 | 60 |
| N | % | |
| Smoking status | ||
| Non-current-smoker | 40 | 63 |
| Current smoker | 34 | 37 |
| Gender | ||
| Male | 74 | 100 |
| Race | ||
| Caucasian | 63 | 85 |
| African–American | 7 | 9 |
| Asian | 2 | 3 |
| Other | 2 | 3 |
| Diabetes (ever) | ||
| No | 69 | 94 |
| Yes | 5 | 6 |
| Asthma (ever) | ||
| No | 69 | 94 |
| Yes | 5 | 9 |
PM2.5 is the average of 1 min averages over the 6-hour shift.
BMI, body mass index; PM, particulate matter