Future trends in local air quality impacts of aviation

Abstract

The International Civil Aviation Organization is considering the use of cost-benefit analyses to estimate interdependencies between the industry costs and the major environmental impacts in policy-making for aviation. To contribute to addressing the needs of the international policy-making community, we propose a reduced-order model to estimate the health impacts of aviation-related air pollution. The model follows an impact pathway approach based on a review of the best practices for air quality policy-making in Europe and the United States. This model is used to develop the Air Quality Module within the Benefits Valuation Block of the Aviation Environmental Portfolio Management Tool. The air quality modeling relies on the intake fraction concept to relate airport-by-airport emissions of particulate matter and particulate matter precursors to the nationwide population exposure to ambient PM2.5. The current modeling capabilities focus on the analysis of the health impacts of aviation in the United States to determine high-priority pollutants and to prioritize model improvements. We show that the health impacts from non-PM pollutants such as ozone are small (4% to 8% of the total aviation-related health impacts).

(cont.) Using emissions inventories from the Federal Aviation Administration tool AEDT/SAGE for the United States in 2005, we estimate PM-related health costs of $1.7 billion per year with a 95% confidence interval ranging from $0.25 to $4.3 billion per year. The costs are dominated by premature mortality estimated at 310 deaths per year (95% CI: 120 - 610 deaths per year). This represents a small fraction (approximately 0.1%) of the total health impacts from anthropogenic air pollution in the United States. Secondary nitrates dominate the impacts and account for 62% of the costs compared to 15% for primary PM exposure and 23% for secondary sulfates. However, the relative contribution of the species depends on the local air composition. While the estimated health impacts in 60% of U.S. counties are dominated by contributions from secondary nitrate PM, in 3% of the counties the impacts are dominated by primary PM, and in 37% of the counties the majority of the health impacts are from secondary sulfate PM. Further, most of the health impacts are associated with the emissions at a few major airports.

(cont.) Using alternative aviation growth scenarios covering a factor of four ranges of growth rates, we show that under the current regulatory framework and technology levels, the major patterns of the aviation impacts on air quality (contributions of each species and geography) remain the same.