Air Quality

The Washington region currently does not meet national air quality standards for ground-level ozone. A major component of smog, ozone is formed on hot summer days when volatile organic compounds (VOCs) and nitrogen oxides (NOx) combine in sunlight. Motor vehicles, as well as power plants and other sources, emit these pollutants.

The Metropolitan Washington Air Quality Committee (MWAQC) works closely with the TPB to develop a regional air quality plan. The plan contains emissions ceilings (called "mobile emissions budgets"), to which the transportation plan must conform. The draft analysis of the plan indicates that mobile emissions are within currently required budgetsfor NOx and VOCs for 2010, 2020, and 2030. The draft Air Quality Conformity Report is available in the Related Links section below.

Mobile Source VOC Emissions for 2007 CLRP and FY 2008-2013 TIP

Mobile Source NOx Emissions for 2007 CLRP and FY 2008-2013 TIP

In addition to NOx and VOCs, the plan must track and estimate Particulate Matter (2.5 micrometers) (PM2.5). PM2.5 is of special concern because these ultra-fine particles can easily permeate the lungs and cause health problems. Concern about PM2.5 has developed relatively recently, and the region is in the processes of establishing a particulate matter budget. PM2.5 was not tracked or estimated in 1990.

PM2.5 Direct and Precursor NOx Emissions for 2007 CLRP and FY 2008-2013 TIP

Related Links:

• Summary Results of the Air Quality Conformity Analysis of the Proposed Plan and TIP