Substance and Perceptions of Environmental Impacts of Dioxin Emissions: An Interim Report

The emission of dioxins is perceived widely as a major environmental impact of combustion processes. This paper will report the results of an extensive study of published data on a) the rate of formation of dioxins from all U.S. sources; b) the pre-MACT and post-MACT performance of individual Waste-to-Energy (WTE) plants in the U.S. and how post-MACT emissions compare with the 1998 EU standard (0.1 ng/dscm); c) how the contribution of WTEs has changed with time; and d) the measured impacts of WTE dioxin emissions on soil/plant concentrations and on public health. The study has shown that since 1987 the U.S. dioxin emissions have decreased by a factor of four and by now WTEs are a miniscule source. Also, that even at the earlier high emission levels, the dioxin levels in soil samples close to WTE facilities did not exhibit an increase over regional background concentrations. Finally, the paper contrasts public perceptions of the dioxin threat with scientific studies of observed effects on the environment and on public health.