Levels of polycyclic aromatic hydrocarbons associated with particulate matter in a highly urbanized and industrialized region in northeastern Mexico

Abstract This paper presents the results of the determination of 13 priority polycyclic aromatic hydrocarbons (PAHs) associated with total suspended particulate (TSP) from the Monterrey Metropolitan Area (MMA), Mexico. The TSP was collected at four locations in MMA (Obispado, Santa Catarina, San Nicolas and Cadereyta Jimenez), and in a rural area (Higueras). Total ∑PAHs in MMA were more in winter (from 32 ± 18 to 116 ± 71 ng m −3 ) than in spring (from 1.0 ± 0.5 to 5.9 ± 2.7 ng m −3 ), and exceeded the levels recorded in the rural area (3 ± 2 ng m −3 in winter and 1.3 ± 1.9 ng m −3 in spring). Between 70 and 90% of the total concentration of PAHs in the MMA was comprised of high molecular weight compounds. The predominant particle types were C-rich (either regularly spherical with smooth surfaces or irregularly shaped). Our results, in addition to the PAH diagnostic ratios, indicate that diesel and gasoline vehicles, industrial furnaces, coal and wood burning were the principal emitting sources of PAHs throughout all study sites. Due to the percent composition, the majority of the PAHs found in ambient air in the MMA are carcinogenic. Our data sets can contribute to the enforcement of PAH regulation in the ambient air in Monterrey.