Field study and source attribution for PM2.5 and PM10 with resulting reduction in concentrations in the neighborhood north of the Houston Ship Channel based on voluntary efforts.

When annual average PM2.5 (fine particulate matter sized 2.5 microns and less) data for 2005 became available in April 2006 and the 3-yr average PM2.

Quality assurance and quality control for thermal/optical analysis of aerosol samples for organic and elemental carbon.

Accurate, precise, and valid organic and elemental carbon (OC and EC, respectively) measurements require more effort than the routine analysis of ambient aerosol and source samples. This paper documents the quality assurance (QA) and quality control (QC) procedures that should be implemented to ensure consistency of OC and EC measurements. Prior to field sampling, the appropriate filter substrate must be selected and tested for sampling effectiveness.