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

Table 2 Average PM_1.5 concentrations by micronenvironment, μg/m³ ^a

Microenvironment or time frame	Mean	Min value	25th quantile	Median	75th quantile	Max value
Home	12.7	0.2	2.5	5.2	14.3	109.5
Transit	9.2	0.1	2.4	5.3	12.2	61.6
School	6.4	0.1	1.9	3.7	8.1	44.9
Complete sample^b	9.5	0.1	2.2	4.7	11.8	109.5

^aStatistics were computed at the subject-day level, not distinguishing between versus within-subject data. Statistics were computed by first determining means within samples (subject, day and microenvironment), then computing statistics across the 125 samples. PM_1.5 is particulate matter less than 1.5 μm in aerodynamic diameter. Home, Transit and School microenvironment times are summarized in the text
^bApproximately 2:30pm through 11:30am the following day

ISSN: 1476-069X