The Impact of African Dust on Annual Average PM_(2.5) Concentrations at the Clinton Drive Monitoring Site, Houston, Texas

摘要

1. The PM_(2.5) annual average at the Clinton Drive monitor has decreased from 16.0 g/m~3 in 2006 to 11.8 g/m~3 in 2015. 2. The Clinton Drive monitor design value for 2015 is 11.6 g/m~3. 3. The calculated impact of African dust on annual average PM_(2.5) at Clinton Drive varies from year to year. 4. From 2009 through 2015, the African dust impact ranged between 0.21 and 1.04 g/m~3. 5. If the 1.04 g/m~3 annual average African dust impact that occurred at Clinton Drive in 2014 had occurred in 2015, the annual average for 2015 would have been 12.3 g/m~3. 6. The EPA exceptional events rule and guidance do not provided a mechanism for selectively removing either natural or anthropogenic international transport contributions from either daily or annual average PM_(2.5) concentrations.