Near-Roadway Pollution and Childhood Asthma: Implications for Developing “Win–Win” Compact Urban Development and Clean Vehicle Strategies

Laura Perez,^1,2 Fred Lurmann,³ John Wilson,⁴ Manuel Pastor,⁵ Sylvia J. Brandt,⁶ Nino Künzli,^1,2 and Rob McConnell⁷

¹Swiss Tropical and Public Health Institute, Basel, Switzerland; ²University of Basel, Basel, Switzerland; ³Sonoma Technology, Inc., Petaluma, California, USA; ⁴Spatial Sciences Institute, and ⁵Program for Environmental and Regional Equity, University of Southern California, Los Angeles, California, USA; ⁶Resource Economics and Center for Public Policy and Administration, University of Massachusetts–Amherst, Amherst, Massachusetts, USA; ⁷Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, USA


Abstract

Background: The emerging consensus that exposure to near-roadway traffic-related pollution causes asthma has implications for compact urban development policies designed to reduce driving and greenhouse gases.


Objectives: We estimated the current burden of childhood asthma-related disease attributable to near-roadway and regional air pollution in Los Angeles County (LAC) and the potential health impact of regional pollution reduction associated with changes in population along major traffic corridors.


Methods: The burden of asthma attributable to the dual effects of near-roadway and regional air pollution was estimated, using nitrogen dioxide and ozone as markers of urban combustion-related and secondary oxidant pollution, respectively. We also estimated the impact of alternative scenarios that assumed a 20% reduction in regional pollution in combination with a 3.6% reduction or 3.6% increase in the proportion of the total population living near major roads, a proxy for near-roadway exposure.


Results: We estimated that 27,100 cases of childhood asthma (8% of total) in LAC were at least partly attributable to pollution associated with residential location within 75 m of a major road. As a result, a substantial proportion of asthma-related morbidity is a consequence of near-roadway pollution, even if symptoms are triggered by other factors. Benefits resulting from a 20% regional pollution reduction varied markedly depending on the associated change in near-roadway proximity.


Conclusions: Our findings suggest that there are large and previously unappreciated public health consequences of air pollution in LAC and probably in other metropolitan areas with dense traffic corridors. To maximize health benefits, compact urban development strategies should be coupled with policies to reduce near-roadway pollution exposure.


Key words: air pollution, asthma, burden of disease, children, compact urban growth, risk assessment, vehicle emissions. 


Environ Health Perspect 120:1619–1626 (2012). http://dx.doi.org/10.1289/ehp.1104785 [Online 24 September 2012]


Address correspondence to R. McConnell, Keck School of Medicine, University of Southern California, 2001 N. Soto St., Los Angeles, CA 90089-9237 USA. Telephone: (323) 442-1096. Fax: (323) 442-3272. E-mail: rmcconne@usc.edu


Supplemental Material is available online (http://dx.doi.org/10.1289/ehp.1104785).


Support for this study was provided by funds from BP as part of an air quality violations settlement agreement between the South Coast Air Quality Management District, a California state regulatory agency, and BP. The study sponsor did not have a role in study design, data collection, analysis or interpretation of data, or manuscript preparation or submission. Other funding support includes the National Institutes of Health grants P30ES007048, P01ES009581, P01ES011627, and R01 ES016535; U.S. Environmental Protection Agency grants #R826708, RD831861, and R831845; and the Hastings Foundation.


F.L. is employed by Sonoma Technology, Inc., Petaluma, CA, an employee-owned for-profit scientific consulting firm that provides expert services in exposure assessment. The other authors declare they have no actual or potential competing financial interests.


Received 25 November 2011; Accepted 5 September 2012; Online 24 September 2012.