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Table 2 Levels of personal exposure to PM 2.5 and Elemental Carbon (EC) during work hours, and of ambient PM 10 on and before the examination days

From: Inhalable particulate matter and mitochondrial DNA copy number in highly exposed individuals in Beijing, China: a repeated-measure study

Time window Office workers Truck drivers
  N Mean SD 10pct 25pct Median 75pct 90pct N Mean SD 10pct 25pct Median 75pct 90pct p-value
Personal PM 2.5 (μg/m 3 ) on the examination days, from personal monitors a  
8 hours 120 94.6 64.9 22.4 48.5 86.2 126.6 183.4 119 126.8 68.8 46.3 73.9 116.8 160.5 213.9 <0.001
Personal EC (μg/m 3 ) on the examination days, from personal monitors a
8 hours 118 13.0 4.0 7.1 10.0 13.2 15.8 18.4 120 17.2 6.6 9.2 12.9 16.7 20.9 26.1 <0.001
Ambient PM 10 (μg/m 3 ) from ambient monitors on the days prior to the examination days
1-day mean 120 121.5 47.8 72.0 82.0 118.0 146.0 186.0 120 119.5 51.2 64.0 82.0 118.0 142.0 188.0 0.76
2-day mean 120 121.6 38.0 74.5 93.0 125.0 146.0 173.0 120 119.3 40.3 66.0 91.0 120.0 144.0 157.0 0.64
5-day mean 120 119.5 26.9 80.7 105.6 119.6 138.0 148.8 120 118.2 25.6 81.0 96.8 119.6 136.8 144.0 0.69
8-day mean 120 119.5 23.0 84.9 101.8 119.9 141.5 146.5 120 120.2 21.5 95.6 102.8 120.4 139.0 146.3   0.81
  1. a Measured during the work hours of examination days using lightweight personal monitors.