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Table 5 Associations between health outcomes (uLTE4 and albuterol usage) and PM1.5 exposure events (increase of at least 5 or 10 μg/m3 within microenvironment) as measured by the personal monitor

From: Within-microenvironment exposure to particulate matter and health effects in children with asthma: a pilot study utilizing real-time personal monitoring with GPS interface

Micro-environment

Exposure event increase

Lag, days

% Increase for exposure event (95 % CI)

Albuterol usage

LTE4

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5μg/m3

0

−1.7 (−17.6, 17.2)

13.3 (−7.6,39.1)

1

11.0 (−10.1, 37.1)

7.4 (−16.0,37.2)

0-1

−1.2 (−17.3, 18.0)

4.1 (−11.5,22.5)

10μg/m3

0

10.3 (−6.5, 30.3)

17.7 (−4.8,45.6)

1

13.4 (−8.3, 40.2)

−3.4 (−23.4,21.8)

0-1

7.6 (−7.6, 25.1)

9.5 (−8.5,31.2)

Transit

5μg/m3

0

9.7 (−5.9, 27.9)

24.0 (1.5,51.5)

1

17.6 (−6.9, 48.6)

17.2 (−3.9,43.1)

0-1

13.7 (−4.3, 35.2)

13.2 (−2.8,31.7)

10μg/m3

0

10.8 (−4.2, 28.2)

10.9 (−10.4,37.2)

1

6.3 (−15.5, 33.6)

8.7 (−12.7,35.2)

0-1

7.3 (−9.5, 27.2)

4.7 (−10.5,22.4)

School

5μg/m3

0

13.3 (−5.7, 36.0)

10.6 (−9.0,34.4)

1

5.9 (−13.2, 29.1)

2.7 (−16.5,26.4)

0-1

1.7 (−14.6, 21.1)

9.0 (−5.2,25.4)

10μg/m3

0

12.4 (−5.2, 33.2)

19.0 (−5.3,49.6)

1

3.1 (−19.3, 31.6)

0.6 (−19.8,26.3)

0-1

4.8 (−11.6, 24.3)

9.1 (−6.0,26.6)

  1. For 0–1 day lag, the indicator was ‘1’ if an event occurred on current or previous day, and ‘0’ otherwise; observations were weighted by the number of records used in the 0–1 variable (1 or 2 days). For Albuterol usage models, temperature and Friday indicator covariates were used; for uLTE4 models, temperature and cold indicator were used (the lag for cold was set as the same for the air pollution variable). 30 subjects were available for analysis; number of records used for model fits were: 114, 80 and 143 for 0, 1 and 0–1 day estimates for albuterol usage, respectively, and 80, 58 and 111 for uLTE4. For more detail, see the text