TY - JOUR
T1 - Spatiotemporal aspects of real-time PM2.5
T2 - Low- and middle-income neighborhoods in Bangalore, India
AU - Both, Adam F.
AU - Balakrishnan, Arun
AU - Joseph, Bobby
AU - Marshall, Julian D.
PY - 2011/7/1
Y1 - 2011/7/1
N2 - We measured outdoor fine particulate matter (PM2.5) concentrations in a low- and a nearby middle-income neighborhood in Bangalore, India. Each neighborhood included sampling locations near and not near a major road. One-minute average concentrations were recorded for 168 days during September 2008 to May 2009 using a gravimetric-corrected nephelometer. We also measured wind speed and direction, and PM2.5 concentration as a function of distance from road. Average concentrations are 21-46% higher in the low- than in the middle-income neighborhood, and exhibit differing spatiotemporal patterns. For example, in the middle-income neighborhood, median concentrations are higher near-road than not near-road (56 versus 50 μg m-3); in the low-income neighborhood, the reverse holds (68 μg m-3 near-road, 74 μg m-3 not near-road), likely because of within-neighborhood residential emissions (e.g., cooking; trash combustion). A moving-average subtraction method used to infer local- versus urban-scale emissions confirms that local emissions are greater in the low-income neighborhood than in the middle-income neighborhood; however, relative contributions from local sources vary by time-of-day. Real-time relative humidity correction factors are important for accurately interpreting real-time nephelometer data.
AB - We measured outdoor fine particulate matter (PM2.5) concentrations in a low- and a nearby middle-income neighborhood in Bangalore, India. Each neighborhood included sampling locations near and not near a major road. One-minute average concentrations were recorded for 168 days during September 2008 to May 2009 using a gravimetric-corrected nephelometer. We also measured wind speed and direction, and PM2.5 concentration as a function of distance from road. Average concentrations are 21-46% higher in the low- than in the middle-income neighborhood, and exhibit differing spatiotemporal patterns. For example, in the middle-income neighborhood, median concentrations are higher near-road than not near-road (56 versus 50 μg m-3); in the low-income neighborhood, the reverse holds (68 μg m-3 near-road, 74 μg m-3 not near-road), likely because of within-neighborhood residential emissions (e.g., cooking; trash combustion). A moving-average subtraction method used to infer local- versus urban-scale emissions confirms that local emissions are greater in the low-income neighborhood than in the middle-income neighborhood; however, relative contributions from local sources vary by time-of-day. Real-time relative humidity correction factors are important for accurately interpreting real-time nephelometer data.
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U2 - 10.1021/es104331w
DO - 10.1021/es104331w
M3 - Article
C2 - 21671645
AN - SCOPUS:79959873411
VL - 45
SP - 5629
EP - 5636
JO - Environmental Science & Technology
JF - Environmental Science & Technology
SN - 0013-936X
IS - 13
ER -