Did the Clean Air Act Amendments of 1990 really improve air quality?
- 308 Downloads
The degree to which federal policies, such as the Clean Air Act (CAA), actually improve air quality is not fully understood. We investigate what portion of reductions in ambient fine particulate matter (PM2.5) that occurred 1999–2005 can be attributed to sulfur dioxide (SO2) and nitrogen oxide (NOx) emissions reductions from implementation of title IV, phase 2, of the 1990 CAA Amendments. A detailed statistical model links sources and receptors over time and space to estimate the relationship between changes in emissions and observed improvements in air quality. We employ relatively transparent statistical methods incorporating uncertainty bounds to complement point estimates of the complex physico-chemical fate and transport models commonly used to estimate source-receptor relationships associated with long-range emissions transport. Monitor-specific estimates of changes in PM2.5 from changes in emissions from individual power plants are highly significant and mostly of the expected relative magnitudes for distance and direction from sources; and the model performs well on out-of-sample forecasts. Although we observe substantial model uncertainty, using our preferred specification, we estimate that the title IV, phase II emissions reduction policy implemented 1999–2005 reduced PM2.5 in the eastern USA by an average of 1.07 μg/m3, roughly 8 % (standard deviation, 0.11 μg/m3) versus a counterfactual of no change in emission rates per unit of energy input. On a population-weighted basis, the comparable reduction in PM2.5 is 0.89 μg/m3, roughly 6 %. This model presents a practical tool that can be used for policy analysis of air quality.
KeywordsClean air act Air pollution Accountability Source receptor
- Burtraw D, Palmer K (2004) SO2 Cap-and-Trade Program in the United States: a “Living Legend” of market effectiveness. In: Harrington W, Morgenstern RD, Sterner T (eds) Choosing environmental policy: comparing instruments and outcomes in the United States and Europe. Resources for the Future Press, WashingtonGoogle Scholar
- Byun, DW and JKS Ching (Eds) (1999) Science Algorithms of the EPA Models-3 Community Multiscale Air Quality (CMAQ) Modeling System. U.S. EPA Office of Research and Development. EPA/600/R-99/030Google Scholar
- Hedley AJ, McGhee SM, Barron B, Chau P, Chau J, Thach TQ, Wong T-W, Loh C, Wong C-M (2008) Air pollution: costs and paths to a solution in Hong Kong—understanding the connections among visibility, air pollution, and health costs in pursuit of accountability, environmental justice, and health protection. J Toxic Environ Health 71:544–554CrossRefGoogle Scholar
- Lee J-T, Son J-Y, Cho Y-S (2007) Benefits of mitigated ambient air quality due to transportation control on childhood asthma hospitalization during the 2002 Summer Asian Games in Busan, Korea. J Air Waste Manag Assoc 57:1047–2389Google Scholar
- Lin C (2010) A spatial econometric approach to measuring air pollution externalities. J Reg Anal Pol 40(1):1–19Google Scholar
- U.S. Environmental Protection Agency (EPA) (1997) The benefits and costs of the Clean Air Act 1970–1990. WashingtonGoogle Scholar
- U.S. Environmental Protection Agency (EPA) (2011) The benefits and costs of the Clean Air Act 1990–2020. EPA Office of Air and Radiation, WashingtonGoogle Scholar
- U.S. EPA (2005) Technical support document for the Final Clean Air Interstate Rule: air quality modeling. Office of Air Quality Planning and Standards, Research Triangle Park, N.C. (March). Available from: http://www.epa.gov/cair/pdfs/finaltech02.pdf. Accessed October 2005