Environ. Sci. Technol. 2002, 36, 2108
Response to ‘Comment on “Formation of Dioxins during the Combustion of Newspapers in the Presence of Sodium Chloride and Poly(vinyl chloride)”’
experiments. Therefore, we believe that the combustion was performed under a well-controlled system. The incinerator we used had actually been used to combust wastes and is equipped with many devices to remove dioxins. The levels of dioxins recovered from the actual system were comparable to those claimed by the authors.
SIR: Our objective of our study was to investigate the formation mechanisms of dioxins from the combustion of materials, not to compare dioxin levels in exhaust gases from different incinerators. Therefore, the authors are attempting to discuss incomparable issues. In our study, to investigate dioxin formation mechanisms in a combustion chamber, the samples were collected directly from the combustion chamber. However, in the studies referred to by the authors, the samples were collected after the exhaust gases had gone through several devices such as a dioxin removal apparatus, a gas trap, and a cooling system. Therefore, it is meaningless to compare the levels of dioxin recovered by our results to theirs. In our combustion experiments, the combustion temperature was well controlled with two subsidiary burners. The samples were introduced in specific amounts continuously. The average oxygen content in the exhaust gases was 12.3%, indicating that the combustion was performed under excess air conditions. Also, the combustion chamber was heated by a subsidiary burner several hours before the
Akio Yasuhara
2108
9
ENVIRONMENTAL SCIENCE & TECHNOLOGY / VOL. 36, NO. 9, 2002
Research Center for Material Cycles and Waste Management National Institute for Environmental Studies 16-2, Onogawa, Tukuba, Ibaraki 305-0061, Japan
Takeo Katami Gifu Prefectural Institute of Health and Environmental Sciences 1-1 Fudogaoka, Naka, Kakamigahara, Gifu 504-0838, Japan
Takayuki Shibamoto* Department of Environmental Toxicology University of California, Davis, Davis, California 95616 ES020544W
10.1021/es020544w CCC: $22.00
2002 American Chemical Society Published on Web 03/27/2002
