Success in Reducing PM_(2.5) in the Neighborhood North of the Houston Ship Channel - Voluntary Efforts Based on Field Study Results and Source Attribution

摘要

When 2005 PM_(2.5) data became available in April 2006 and the three-year average PM_(2.5) concentration just to the north of the Houston Ship Channel reached 15.0 μg/m~3, the TCEQ initiated daily collection of quartz fiber as well as Teflon PM_(2.5) filter samples for chemical speciation analysis. Data analysis methods included positive matrix factorization (PMF), wind direction analysis for total mass, for species, and for PMF factors. The PMF analyses identified two mineral factors as the principal difference between this site (Clinton Drive) and other sites in the area. One was composed of typical soil elements. The other consisted of calcium sulfate, which was a by-product of an industrial process, plus additional calcium, which may have come from oyster shell or crushed concrete or both. Voluntary efforts by local businesses, the Port of Houston Authority, and city and county governments took hold and reduced PM_(2.5) concentrations significantly by the end of 2007. The paper describes these voluntary efforts and the resulting changes in concentration of the species making up PM_(2.5) impacting the Clinton Drive site and the Galena Park neighborhood north of the Houston Ship Channel area. The 2005 - 2007 PM_(2.5) annual averages were 15.9, 16.0, and 15.6 μg/m~3, respectively. The 2008 - 2011 averages were 14.0, 12.6, 12.3, and 12.3 μg/m~3. In 2006 the PM_(2.5) average at Clinton Drive was 2.6 μg/m~3 higher than a similar site 3 miles away; by 2009 the difference was reduced to 0.5 μg/m~3.