Particulate emissions of tire combustion

The disposal of used tires represents an environmental and health hazard, especially when large stockpiles of tires start on fire. This study focuses on ambient particulate matter samples collected during the Iowa City landfill tire fire and laboratory emissions of tire combustion. Levels of elemental (EC) and organic carbon (OC), metals, polycyclic aromatic hydrocarbons (PAH), azaarenes and oxygenated PAH (oxy-PAH) were determined by thermo-optical analysis, high precision mass, inductively-coupled plasma mass spectrometry and gas chromatography mass spectrometry. Results demonstrate that tire combustion emissions are enriched in elemental carbon and PAH. Levels of hazardous metals, such as lead and zinc, are not enhanced in particulate emissions 4.2 km from the fire. In addition, fresh tire combustion emissions have increased amounts of lower molecular weight PAH in the particle phase when compared to diluted real world emissions. This is due to gas phase partitioning of lower molecular weight PAH in plume transport. To build on the prior, qualitative understanding of organic compounds in tire emissions, 15 total azaarenes and oxy-PAH were identified, including four azaarenes and three oxy-PAH that were identified in tire combustion emission for the first time. The combustion of tires has significant health implications, particularly when open burning occurs near populations. This study serves to characterize the major chemical components of tire smoke and to quantify emissions of select chemicals with known carcinogenic, mutagenic, and toxic effects.