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LEA Advisory #46 -Evaluation of Employee Health Risk from Open Tire Burning Page 4 of 8 <br /> information). <br /> In a controlled burn chamber simulating open burning of scrap tires, a U.S. EPA report estimated <br /> emissions of semivolatile organics ranged from 10 to 50 g/kg of tire material burned. It is likely that <br /> emissions measured during this study characterize an actual fire, but the similarity of actual gaseous <br /> concentrations and estimated emissions may not be representative. The predominant emission <br /> products identified were monoaromatic and polyaromatic hydrocarbons. The presence of benzo(a) <br /> pyrene in particulate extracts is notable because of the compound's carcinogenicity. High emissions <br /> of other compounds, particularly benzene, with concentrations often exceeding 1 ppm, may pose a <br /> significant health risk. Zinc and lead in gaseous particulate was also verified and quantified. (See <br /> paper for more specific emission data information.) <br /> Examination and characterization experiments measuring emissions from combustion of scrap tire <br /> material were performed in a rotary kiln incinerator simulator. These experiments allowed controlled <br /> combustion where feed rates, temperatures, and oxygen concentrations could be controlled and <br /> varied. Results indicated that, if burned in a steady-state mode, tire-derived fuel combustion will <br /> result in very low emissions of carbon monoxide, total hydrocarbons, volatile and semivolatile <br /> organics, and metal aerosols. (See paper for more specific emission data information.) <br /> Polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) were <br /> measured in ambient air during a burning tire fire. Concentrations of PCDDs and PCDFs in ambient <br /> air, converted to toxicity equivalents (TEQ) by application of the International Toxicity Equivalency <br /> Factors showed sites one kilometer (km) downwind of the fire were an order of magnitude higher <br /> than at three kms downwind. Steer, et.al. reported that measurement of volatile organic compounds <br /> (VOC) and polycyclic aromatic hydrocarbons (PAH) measured both in the plume and downwind of <br /> the source showed no PCDDs or PCDFs. <br /> Potential Environmental Contamination <br /> Uncontrolled open tire burning poses potential environmental effects by contamination of the soil, <br /> and ground and surface water. The two fire by-products, which pose a major concern, are the <br /> generation of pyrolytic oil and ash. <br /> Because of the starved-air conditions and the intense heat generated by an uncontrolled tire fire, <br /> pyrolytic reactions occur, producing a free-flowing, oily tar. This pyrolytic oil product consists of <br /> naphthalenes, anthracene, benzenes, thiazoles, amines, ethyl benzene, toluene, and other <br /> hydrocarbons. Also included are metals such as cadmium, chromium, nickel and zinc. This pyrolytic <br /> oil material can contaminate soil, and ground and surface water surrounding the site. Maximum <br /> production of the pyrolytic oil material occurs at about 200°C and exhibits properties similar to <br /> heating oil. In a field-scale gasification reactor it was found that a greater portion of pyrolytic oil was <br /> produced at the beginning of the process. Water applied to tire fires often increases the production of <br /> pyrolytic oil and provides a method of transport for the oils to move off site and accelerate <br /> contamination of soils and water. <br /> Analyses of ash produced as a by-product of tire fires typically show the presence of heavy metals. <br /> High concentrations of metals such as lead, cadmium, and zinc are not uncommon. Fly ash has been <br /> shown to be rich in zinc, probably due to the fact that zinc is found in the curing agent during tire <br /> manufacturing. <br /> http://www.ciwmb.ca.gov/pe/advisory/46/46.htm 8/11/98 <br />