Long-term source apportionment of ambient fine particulate matter (PM2.5) in the Los Angeles Basin: a focus on emissions reduction from vehicular sources

Sina Hasheminassab; Nancy Daher; Bart D Ostro; Constantinos Sioutas

doi:10.1016/j.envpol.2014.06.012

Long-term source apportionment of ambient fine particulate matter (PM2.5) in the Los Angeles Basin: a focus on emissions reduction from vehicular sources

Environ Pollut. 2014 Oct:193:54-64. doi: 10.1016/j.envpol.2014.06.012. Epub 2014 Jul 5.

Authors

Sina Hasheminassab¹, Nancy Daher¹, Bart D Ostro², Constantinos Sioutas³

Affiliations

¹ University of Southern California, Department of Civil and Environmental Engineering, Los Angeles, CA, USA.
² Air Pollution Epidemiology Section, Office of Environmental Health Hazard Assessment, State of California, Oakland, CA, USA.
³ University of Southern California, Department of Civil and Environmental Engineering, Los Angeles, CA, USA. Electronic address: sioutas@usc.edu.

PMID: 25005887
DOI: 10.1016/j.envpol.2014.06.012

Abstract

Positive Matrix Factorization (PMF) was utilized to quantify sources of ambient PM2.5 in central Los Angeles (LA) and Rubidoux, using the Speciation Trends Network data, collected between 2002 and 2013. Vehicular emissions (including gasoline and diesel vehicles) were the second major contributor to PM2.5, following secondary aerosols, with about 20% contribution to total mass in both sites. Starting in 2007, several major federal, state, and local regulations on vehicular emissions were implemented. To assess the effect of these regulations, daily-resolved vehicular source contributions from 2002 to 2006 were pooled together and compared to the combination of 2008 to 2012 datasets. Compared to the 2002-2006 dataset, the median values of vehicular emissions in 2008-2012 statistically significantly decreased by 24 and 21% in LA and Rubidoux, respectively. These reductions were noted despite an overall increase or similarity in the median values of the daily flow of vehicles after 2007, at the sites.

Keywords: Los Angeles Basin; PM(2.5); Positive matrix factorization; Source apportionment; Vehicular emissions reduction.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Aerosols / analysis
Air Pollutants / analysis*
Environmental Monitoring*
Gasoline / analysis
Los Angeles
Particulate Matter / analysis*
Vehicle Emissions / analysis*

Substances

Aerosols
Air Pollutants
Gasoline
Particulate Matter
Vehicle Emissions