Dioxin emission inventories and trends: the importance of large point sources

We estimated atmospheric emissions of TEQ for US municipal solid waste incinerators for which PCDD/PCDF measurements are available (81 of about 160 facilities). We compared our annual totals for 1985–1995 with estimates computed using the emission factor approach. Our estimates for a fraction of the facilities was larger than many estimates for all incinerators combined. Our inventory was dominated by several large sources; two facilities emitted on the order of a kilogram of TEQ annually. Retrofit or closing of several incinerators indicates a substantial decrease in atmospheric emissions. Communities addressing the remaining sources will face a choice between expensive retrofits and adoption of alternative methods of handling waste.