"ESTIMATION OF THE ANNUAL AVERAGE PCDD/FS CONCENTRATIONS IN THE AMBIENT AIR FROM THE LIMITED MONITORING DATA" 

Haruyuki Higashino

National Institute of Advanced Industrial Science and Technology

8th International Conference for Atmospheric Sciences and Applications to Air Quality (Tsukuba, Japan 2003/3/13)

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Abstract

In the study correlations between PCDD/Fs and reciprocal of wind velocity were good in the urban area of Tokyo. In general there is a good correlation between the pollutant concentration and reciprocal of wind velocity. However, these were not good on the suburb area. The reason of these results seems to be that emission amounts from each wind directions were not similar there.

SPM concentrations were the best correlated with PCDD/Fs concentrations. The first reason of these results seems to be that the main sources of PCDD/Fs are waste incineration facilities and SPM is also emitted from them. The second reason seems to be that the most of PCDD/Fs adsorb particle and they may behave like SPM. But in a few monitoring stations the correlations were not good. The reason of these results seems to be that the sources of PCDD/Fs are different from those of SPM around these stations.

For the validation of the methodology to estimate annual average concentration by the wind velocity, we used SPM data, in which sufficient data are available. The correlations between SPM concentration and wind velocity are good. The regression equations between SPM concentration and reciprocal of wind velocity were calculated to estimate annual average SPM concentrations. Although arithmetic average SPM concentrations when PCDD/Fs were measured were lower than actual annual average, annual average estimated were the almost same level as actual annual average. These results seem to suggest the validation of the methodology.

We estimated annual average PCDD/Fs concentrations by using the wind velocity. Estimated annual average PCDD/Fs concentrations are 10% higher than arithmetic average when PCDD/Fs were measured. The almost same results were obtained by using SPM concentrations instead of the wind velocity. These results show that actual annual average PCDD/Fs concentrations were higher than arithmetic average of monitoring data.

Keywords

dioxin, spm, concentration, wind speed, Tokyo