TITLE:
Sources Affecting PM2.5 Concentrations at a Rural Semi-Arid Coastal Site in South Texas
AUTHORS:
Saritha Karnae, Kuruvilla John
KEYWORDS:
Positive Matrix Factorization (PMF2); Principal Component Analysis/Absolute Principal Component Scores (PCA/APCS); Coastal; Industrialized Urban
JOURNAL NAME:
Journal of Environmental Protection,
Vol.4 No.1,
January
29,
2013
ABSTRACT:
Principal
component analysis/absolute principal component scores (PCA/APCS) and positive
matrix factorization (PMF2), an advanced factor analysis technique were
employed to apportion the sources influencing the PM2.5 levels
measured during 2003 through 2005 at a rural coastal site located within the
Corpus Christi urban airshed in South Texas. PCA/APCS identified five sources
while PMF2 apportioned an optimal solution of eight sources. Both PCA/APCS and
PMF2 quantified secondary sulfates to be the major contributor accounting for
47% and 45% of the apportioned PM2.5 levels. The other common
sources apportioned by the models included crustal dust, fresh sea salt and
traffic emissions. PMF2 successfully apportioned distinct sources of fresh and
aged sea salt along with biomass burns while PCA/APCS was unsuccessful in
identifying aged sea salt and biomass burns; however it successfully identified
secondary organic aerosols from photochemical oxidations and also emitted by
petrochemical refineries. The influence of long range transport was noted for
sources such as secondary sulfates, biomass burns and crustal dust affecting
the region. Continued collection of speciation data at the rural and urban
sites will enhance the understanding of local versus regional source
contributions for air quality policy makers and stakeholders.