Lower exposure | Moderate exposure | Higher exposure | ||||
---|---|---|---|---|---|---|
Wind condition | 0.1 m/s | 0.1 m/s | 0.1 m/s | |||
Length of shift worked outdoors | 4 h | 8 h | 4 h | 8 h | 4 h | 8 h |
Number of lit cigarettes present at all times† | 0.4 lit cigarettes | 0.4 lit cigarettes | 0.7 lit cigarettes | 0.7 lit cigarettes | 1.0 lit cigarette | 1.0 lit cigarette |
Cigarette emission factor (CEF) (constant)‡ | 1.4 mg/min | 1.4 mg/min | 1.4 mg/min | 1.4 mg/min | 1.4 mg/min | 1.4 mg/min |
Total cigarette emissions (# lit cigarettes* CEF) | 0.56 mg/cigarette | 0.56 mg/cigarette | 0.98 mg/cigarette | 0.98 mg/cigarette | 1.4 mg/cigarette | 1.4 mg/cigarette |
Average air pollution concentration across all distances and angles§ | 42.8 μg/m3 | 42.8 μg/m3 | 42.8 μg/m3 | 42.8 μg/m3 | 42.8 μg/m3 | 42.8 μg/m3 |
Average exposure for 8-hr Shift* | 24.0 μg/m3 | 24.0 μg/m3 | 41.9 μg/m3 | 41.9 μg/m3 | 59.9 μg/m3 | 59.9 μg/m3 |
Assumed ambient air concentration (constant)¶ | 6.5 μg/m3 | 6.5 μg/m3 | 6.5 μg/m3 | 6.5 μg/m3 | 6.5 μg/m3 | 6.5 μg/m3 |
Excess exposure above ambient air concentration* | 17.5 μg/m3 | 17.5 μg/m3 | 35.4 μg/m3 | 35.4 μg/m3 | 53.4 μg/m3 | 53.4 μg/m3 |
24-h excess PM2.5 Exposure from occupational OTS* | 2.9 μg/m3 | 5.8 μg/m3 | 5.9 μg/m3 | 11.8 μg/m3 | 8.9 μg/m3 | 17.8 μg/m3 |
Annual excess PM2.5 exposure from occupational OTS* | 2.0 μg/m3 | 4.0 μg/m3 | 4.0 μg/m3 | 8.1 μg/m3 | 6.1 μg/m3 | 12.2 μg/m3 |
*See appendix B, uploaded as ‘Web Only’ material, for an explanation of all calculations.
†From Cameron et al 29: active smoking was present 38.4% of the total observation time; From Stafford et al 30, active smoking was present 71.2% of the total observation time. The higher exposure category is an estimate of when one cigarette is present at all times over the entire 8 h shift.
‡Klepeis et al 57 first reported the average fine particulate emission rate for cigarettes of 1.4 mg/min.
§Klepeis et al 51—this figure (42.8 μg/m3) was calculated from table 3 using light wind (0.1m/s) speeds
¶Ambient levels averaged 6.5 μg/m3 across observational studies, which were usually measured at off-site locations where no smoking was observed to occur. Brennan: 5 μg/m3, Cameron: 8 μg/m3, Perry: 6 μg/m3, Stafford: 4 μg/m3, Wilson et al 32: 14 μg/m3, and Wilson et al 6: 2 μg/m3.
PM, particulate matter.