MATERIALS AND METHODS
Sampling. A number of different energy sources such as electricity, liquefied petroleum gas,coal gas, fuel oil, and natural gas are used as energy sources in ceramic kilns. Six ceramic plants (numbered CP-1 to CP-6) fuelled by natural gas were selected as the research sites. Foregoing analysis showed that dioxins were not detected from the natural gas used,eliminating potential dioxin emission from fuel combustion. Hence, the raw clay was identified as the main source of
dioxins