Potential risk of exposure to heavy metals from co-processing of secondary wastes in the Republic of Korea

Abstract

The co-processing of secondary wastes during ordinary Portland cement (OPC) can result in high heavy metal concentrations in OPC products. However, earlier studies have not evaluated the concentrations of heavy metals (HMs) in OPC as a function of secondary input materials. Further, the health risk assessment (HRA) model has, thus far, has not been employed to assess the potential health risks associated with secondary raw materials and secondary fuels in OPC. Hence, to address these knowledge gaps, herein, monthly data for six HMs in the input materials and fuels from seven OPC manufacturers in the Republic of Korea were analyzed and modeled. Pb and Cu concentrations were found to be approximately 10–200 and 4–200 times higher than those of the other HMs, respectively. Furthermore, maximum Pb and Cu concentrations were 2–3 and 2–5 times higher than those reported in other countries, respectively. The quantity of input material had a significant influence on the observed patterns, and secondary raw materials, secondary additives, and secondary fuels were also determined to be important. Based on HRA assessment, although the risk levels were within permissible ranges, carcinogenic hazards attributable to Cr and Pb were not negligible. The results can aid in informed decision making and in implementing effective measures for managing risks associated with HMs in the OPC industry, thereby ameliorating threats to human health and environment.