It has been demonstrated that most heavy metals that are in the fuels or raw materials used in cement kilns are effectively incorporated into the clinker, or contained by standard emissions control devices (WBCSD 2002; European Commission (EC) 2004; Vallet January 26, 2007). A study using the EPA’s toxicity characteristic leaching procedure to test the mobility of heavy metals in clinker when exposed to acidic conditions found that only cadmium (Cd) could be detected in the environment, and at levels below regulatory standards (5 ppm) (Shih 2005). As long as cement kilns are designed to meet high technical standards,.