title: Spatiotemporal aspects of real-time PM(2.5): low- and middle-income neighborhoods in Bangalore, India.
abstract: We measured outdoor fine particulate matter (PM(2.5)) 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 PM(2.5) 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.
authors.affiliation: Department of Civil Engineering, University of Minnesota, Minneapolis, Minnesota, United States.
authors.forename: Adam F
authors.initials: AF
authors.lastname: Both
authors.forename: Arun
authors.initials: A
authors.lastname: Balakrishnan
authors.forename: Bobby
authors.initials: B
authors.lastname: Joseph
authors.forename: Julian D
authors.initials: JD
authors.lastname: Marshall
mesh_terms: D002947:Cities; D004784:Environmental Monitoring / Q000379:methods / Q000706:statistics & numerical data*; D007194:India; D009391:Nephelometry and Turbidimetry; D052638:Particulate Matter / Q000032:analysis*; D012959:Socioeconomic Factors; D014919:Wind
chemical_list: D052638:Particulate Matter