More than 30 percent of the tires scrapped last year were tossed into landfills. Proponents of tire burning argue the cement-making process is especially suited to disposing of tires. The process that slowly super-heats limestone combusts the tire completely, steel belts and all. Any ash or oxidized metals become part of the product. Blumenthal says the answer is yes.
Some environmentalists say the practice benefits industry more than the environment.
RMC Lonestar, a cement plant in Davenport, near Santa Cruz, gave up its plan to burn scrap tires three years ago in the face of citizen and local government opposition. Tire burning at California Portland Cement near Mojave was stopped when a judge withdrew the company's permit until an environmental impact report was conducted. Leslie Byster of the Silicon Valley Toxics Coalition argues that the quality of the ambient air in Santa Clara County is already poor. Measured in health risk per million, downtown San Jose scores 500 while the rest of the Bay Area averages about 300. According to estimates released by Austin-based Radian, an environmental contractor for government and industry, Kaiser's emissions contribute a total health risk of 4.6.