Tires burning and Dioxin?

["Dian R. Deevey" <diandv@taconic.net>]

I  have heard diametrically opposed views of whether tires, burned
as a substitute fuel in Portland cement kilns result in higher dioxin emissions
than the normal fuel, assuming that fuel is coal from eastern US sources
(that is "dirty" coal).

Experts at the EPA assure me that their review of the literature confirms that the composition of tires is similar to coal with some exceptions, depending on the source of the fuel, and the ratio of tires to regular fuel.   As a result, there may be minor differences in trace metal emissions, (more lead) but essentially no difference in the production of dioxins.

I have also heard rumors of other studies showing that dioxin production is raised during tire burning.   Views, anyone?  And citations?

Dian Deevey