Background

Emerging evidence indicates that the near-roadway air pollution (NRAP) mixture contributes to CHD, yet few studies have evaluated the associated costs.

Objective

We integrated an assessment of NRAP-attributable CHD in Southern California with new methods to value the associated mortality and hospitalizations.

Methods

Based on population-weighted residential exposure to NRAP (traffic density, proximity to a major roadway and elemental carbon), we estimated the inflation-adjusted value of NRAP-attributable mortality and costs of hospitalizations that occurred in 2008. We also estimated anticipated costs in 2035 based on projected changes in population and in NRAP exposure associated with California's plans to reduce greenhouse gas emissions. For comparison, we estimated the value of CHD mortality attributable to PM less than 2.5μm in diameter (PM_2.5) in both 2008 and 2035.

Results

The value of CHD mortality attributable to NRAP in 2008 was between $3.8 and $11.5 billion, 23% (major roadway proximity) to 68% (traffic density) of the $16.8 billion attributable to regulated regional PM_2.5. NRAP-attributable costs were projected to increase to $10.6 to $22 billion in 2035, depending on the NRAP metric. Cost of NRAP-attributable hospitalizations for CHD in 2008 was $48.6 million and was projected to increase to $51.4 million in 2035.

Conclusions

We developed an economic framework that can be used to estimate the benefits of regulations to improve air quality. CHD attributable to NRAP has a large economic impact that is expected to increase by 2035, largely due to an aging population. PM_2.5-attributable costs may underestimate total value of air pollution-attributable CHD.