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Table 2 Description of joint exposures

From: Adult asthma and traffic exposure at residential address, workplace address, and self-reported daily time outdoor in traffic: A two-stage case-control study

The 2nd survey

 

NOx at workplace address (μg/m3)

Time outdoor in traffic/day (self-reported)

 
  

total

0-8

8-11

11-14

14-19

> 19

Total

0-30 min

30-1 h

1-2 h

> 2 h

NOx at residential address (μg/m3)

0-8

770

412(53.5%)

78(10.1%)

132(17.1%)

60(7.8%)

88(11.4%)

770

159(20.6%)

306(39.7%)

188(24.4%)

117(15.2%)

 

8-11

210

30(14.3%)

44(21.0%)

59(28.1%)

32(15.2%)

45(21.4%)

210

34(16.2%)

87(41.4%)

55(26.2%)

34(16.2%)

 

11-14

210

13(6.2%)

15(7.1%)

102(48.6%)

26(12.4%)

54(25.7%)

210

41(19.5%)

88(41.9%)

65(31.0%)

16(7.6%)

 

14-19

161

4(2.5%)

7(4.3%)

38(23.6%)

39(24.2%)

73(45.3%)

161

29(18.0%)

65(40.4%)

41(25.5%)

26(16.1%)

 

> 19

137

9(6.6%)

4(2.9%)

18(13.1%)

26(19.0%)

80(58.4%)

137

20(14.6%)

53(38.7%)

37(27.0%)

27(19.7%)

  1. Percentage within row total. Exposure to residential traffic was predictive of exposure at workplace address, but less predictive of time spent outdoor in traffic. The first row shows that of those who live at a residential address with 0-8 ug NOx/m3, 53.5% also have a workplace address with 0-8 ug NOx/m3 and 20.6% spend 0-30 min outdoor in traffic/day.