This study focuses on the atmospheric deposition of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) on the soils
in the vicinity of two municipal solid waste incinerators (MSWIs), which were located in the Gangshan (GS) and the Renwu (RW)
Townships of southern Taiwan. PCDD/Fs in the soils were sampled simultaneously with those in the ambient air and analyzed for 17
2,3,7,8-substituted PCDD/Fs. The results showthat the mean contents of PCDD/Fs in the soils near MSWI-GS and MSWI-RWwere
2.65 and 1.20 ng I-TEQ/kg dry weight, respectively. Annual wet deposition fluxes of total PCDD/Fs were 119 and 113 ng/m2-year in
the ambient air near MSWI-GS and MSWI-RW, respectively. The results obtained in this study are much higher than those estimated
for the Atlantic Ocean, where the average wet deposition was only 45 ng/m2-year. The annual dry deposition fluxes accounted for
58.2 and 66.7%, respectively, indicating that dry deposition was more dominant than wet deposition in the atmospheric deposition
processes. The congener profiles of 17 2,3,7,8-substituted PCDD/Fs showed that OCDD dominates in the soils. The contributions
of OCDD in the soils near MSWI-GS and MSWI-RW were 73.4 and 67.1%, respectively, while they were only 41.4 and 31.2% in
the atmospheric deposition, respectively. These results imply that OCDD is more persistent in the environment than other congeners.
The results of the present study strongly suggest that exposure to PCDD/Fs in these areas should be reduced.