Valuing the Air Quality Effects of Biochar Reductions on Soil NO Emissions
 Rice Univ, Inst Publ Policy, Ctr Energy Studies, Houston, TX 77005 USA;  Rice Univ, Dept Earth Environm & Planetary Sci, Houston, TX 77005 USA;  Rice Univ, Dept Civil & Environm Engn, Houston, TX 77005 USA;  Rice Univ, Dept Biosci, Houston, TX 77005 USA;  Rice Univ, Dept Chem, POB 1892, Houston, TX 77005 USA
While it is clear that biochar can alter soil N2O emissions, data on NO impacts are scarce. Reports range from O to 67% soil NO emission reductions postbiochar amendment. We use regional air quality and health cost models to assess how these soil NO reductions could influence U.S. air quality and health costs. We find that at 67% soil NO reduction, widespread application of biochar to fertilized agricultural soils could reduce O-3 by up to 2.4 ppb and PM2.5 by up to 0.15 mu g/m(3) in some regions. Modeled biochar-mediated health benefits are up to $4.3 million/county in 2011, with impacts focused in the Midwest and Southwest. These potential air quality and health cobenefits of biochar use highlight the need for an improved understanding of biochar’s impacts on soil NO emissions. The benefits reported here should be included with estimates of other biochar benefits, such as crop yield increase, soil water management, and N2O reductions.
Citation: Pourhashem, G., Rasool, Q. Z., Zhang, R., Medlock, K. B., Cohan, D. S., & Masiello, C. A. (2017). Valuing the Air Quality Effects of Biochar Reductions on Soil NO Emissions. Environmental Science & Technology, 51(17), 9856–9863. https://doi.org/10.1021/acs.est.7b00748