Chemical composition of PM2.5 particles in Salamanca, Guanajuato Mexico: Source apportionment with receptor models

Abstract The National Institute of Ecology, through Management General for Environmental Research and Training (DGCENICA) carried out a sampling campaign where a total of 21 elements were determined in 140 PM 2.5 samples from one sampling site located in the city of Salamanca, Guanajuato-Mexico between November 2006 and November 2007. The annual average PM 2.5 concentration was 45 μg/m 3 almost three times the Mexican Annual standard for PM 2.5 . Mineral, organic and elemental carbon were the most important components present in particles PM 2.5 . Two advanced receptor models, UNMIX and positive matrix factorization (PMF) were used for PM 2.5 source identification. Four and six sources were identified by UNMIX and PMF, respectively, from a combined dataset including 15 chemical species. Source categories were determined based on both, component abundances in the source profiles, and their temporal characteristics. Overall, different sources were identified as the major contributors: heavy fuels combustion, traditional brick production-agricultural burning, crustal, road traffic and secondary organic aerosols.