Skip to main content

View full-text article in PMC

. Author manuscript; available in PMC: 2009 Oct 1.

Published in final edited form as: Atmos Environ (1994). 2008 Oct;42(33):7590–7599. doi: 10.1016/j.atmosenv.2008.06.041

TABLE 2.

PM_2.5 Concentrations (μg/m³) Measured Aboard the Bus, Lead Vehicle, and Estimates of Self Pollution

	Overall		Seattle		Tahoma
	N	Mean (SD)	N	Mean (SD)	N	Mean (SD)
All Trips
Bus	85	20.9 (11.9)	46	20.6 (14.1)	39	21.4 (9.0)
Lead Vehicle	57	12.4 (8.0)	35	12.9 (8.4)	22	11.6 (7.5)
Ambient	117	4.8 (3.4)	63	6.0 (3.6)	54	3.4 (2.7)
Paired Trips^a
Bus	46	19.7 (10.8)	25	19.1 (11.5)	21	20.5 (10.1)
Lead Vehicle	46	12.7 (8.4)	25	13.3 (9.2)	21	12.0 (7.5)
Bus Self-Pollution	46	7.0 (9.0)	25	5.8 (9.1)	21	8.5 (8.9)
Ambient	44	5.5 (4.2)	25	6.9 (4.5)	19	3.7 (2.8)

^a

Paired trips imply that a bus and lead vehicle drove the same route simultaneously.