A study examines the impacts of hypothetical air pollution exposure scenarios on childhood asthma rates in Southern California. Although there is evidence that air pollution exposure causes asthma, the benefits of reducing exposure have not been well explored. Erika Garcia and colleagues analyzed data from the Southern California Children's Health Study in which 525 incident asthma cases were identified among 4,140 fourth graders between 1993 and 2014. If nitrogen dioxide (NO2) levels had not decreased from an average of 24.0 ppb in 1993 to an average of 17.8 ppb in 2006, the authors estimated that the asthma incidence rate would have been 19.3% higher. In hypothetical interventions where NO2 levels were reduced by 30%, the asthma incidence rate was 27.6% lower. Moreover, the authors estimated that the asthma incidence rate would have been 19.6% lower compared with the natural course had communities adhered to a hypothetical air quality standard of 20 ppb NO2. Smaller estimated benefits were found for fine particulate matter (PM2.5). For example, in a hypothetical scenario where PM2.5 was reduced by 30%, the asthma incidence rate was 12.8% lower. The findings suggest that increasing the stringency of air quality standards may result in increased public health benefits, according to the authors.
Article #18-15678: "Effects of policy-driven hypothetical air pollutant interventions on childhood asthma incidence in southern California," by Erika Garcia, Robert Urman, Kiros Berhane, Rob McConnell, and Frank Gilliland.
MEDIA CONTACT: Leigh Hopper, University of Southern California, Los Angeles, CA; tel: 310-308-0405; email: lhopper@usc.edu
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Journal
Proceedings of the National Academy of Sciences