Concentrations and profiles of PCDD/Fs in ambient air around a municipal solid waste incinerator

The concentrations and profiles of PCDD/Fs in ambient air around a municipal solid waste incinerator (MSWI) in an industrial area were obtained. The concentrations of 2, 3, 7, 8-PCDD/Fs of the 14 ambient air sampling sites were in the range of 1.74-15.2 pg/m3 (0.156-1.44 pg I-TEQ/m3), with an average value of 4.60 pg/m3 (0.426 pg I-TEQ/m3), and the levels of 3 sampling sites were higher than the ambient air standard of 0.6 pg TEQ m-3 for dioxins proposed by Japan, which demonstrated that the PCDD/Fs concentrations around the MSWI in some area in this study were a bit high. And the highest concentration of 2, 3, 7, 8-PCDD/Fs was found at a downwind location, 1.3 km away from the MSWI, which was consisted with the result of the maximum ground concentration calculated by AERMOD models. 1, 2, 3, 4, 6, 7, 8-HpCDF and OCDD were the dominated PCDD/Fs in all the samples, while 2, 3, 4, 7, 8-PeCDF was the dominated congener contributed to the total toxicity equivalent (TEQ). The homologue profiles of PCDD/Fs in some ambient air locations were similar to those in the flue gas of the MSWI, indicating the possibility of influence by the source, while the profiles of other sites differed with them with a significantly higher TCDD contribution. Principal component analysis (PCA) results revealed that the concentrations of PCDD/Fs in ambient air in some areas were obviously affected by the MSWI, which was coincided with the fingerprint analysis. Dioxin inhalation exposure dose estimation results showed that the dioxin inhalation exposure risk of the population living in the study areas was still at a relative safe level.