Benefits evaluation points

2000 and 2010

Scenarios

Evaluated conditions with and without implementation of Titles I-V of the 1990 Clean Air Act Amendments

Pollutants modeled and methods used for air-quality modeling for benefits analysis

Ozone – regional-scale version of the urban airshed model (UAM-V) for eastern and western United States; UAM-IV for Los Angeles, San Francisco, and Phoenix

PM₁₀ and PM_2.5 – regional acid deposition model/regional particulate model for the eastern United States; regulatory modeling system for aerosols and acid deposition for the western United States

CO, NO_x, and SO₂ – linear scaling procedure based on percent reduction in emissions

Health outcomes quantified and monetized^a

Ozone – chronic asthma; minor restricted-activity days and respiratory symptoms; hospital admissions (respiratory and cardiovascular illness); emergency room visits for asthma

PM – premature mortality; bronchitis (chronic and acute); hospital admissions (respiratory and cardiovascular illness); emergency room visits for asthma; lower and upper respiratory symptoms; shortness of breath; minor restricted-activity days and respiratory symptoms; work-loss days

CO – hospital admissions (respiratory and cardiovascular illness)

NO_x – hospital admissions (respiratory and cardiovascular illness); respiratory illness

SO₂ – hospital admissions (respiratory and cardiovascular illness); chest tightness, shortness of breath, or wheeze

Concentration-response function used to estimate mortality benefits

Pope et al. (1995)

Threshold assumptions

No thresholds above background concentrations assumed for modeled health outcomes