환경 중 잔류성유기오염물질의 분포 특성 및 오염원 추정

Abstract

This study was performed to investigate the persistent status of POPs in Korea using environment medias such as air, soil, water and the surface sediment. Also the study identified the source and fugacity of POPs using congener analyses of PCDD/Fs and OCPs, principal component analysis(PCA) and Cluster analysis(CA). The obtained results are summarized as follow; As a comprehensive monitoring survey on POPs in korea, 111 ambient air samples taken from 37 locations during four different seasons were studied. PCDD/Fs concentrations ranged from 0.067 to 12.41 pg/Sm3, and WHO-TEQ values ranged from 0.003 to 0.285 pg/Sm3WHO-TEQ. In all samples, the dominant congeners were OCDD, 1,2,3,4,6,7,8-HpCDF, 1,2,3,4,6,7,8-HpCDD, OCDF and 2,3,4,7,8-PeCDF, and the congener profiles did not display any seasonal trend. According to Principal component analyses, dioxin emissions in ambient air assumed to be originated from flue gas, vehicle and sinter plants. The concentrations of OCPs exhibited the highest in summer due to volatilization of OCPs to the ambient air from other environment media, such as soil. However, there was no concentration variation related to temperature in Chlordane. For each chlordane compound, the concentration of trans-Chlordane was 1.586 times higher than that of cis-Chlordane. According to the results, it is possible to assume that Chlordanes found in Korean ambient air are not residue of early usage, but from recent usage in remote areas. For DDTs, the concentration ratio of p,p’-DDT and the degrading metabolite p,p’-DDE were determined to discover the source of DDTs. The average ratio of p,p’-DDT/p,p’-DDE was relatively low (about0.341) which means there is no significant input of fresh DDT, and that the degrading of residues are processing. POPs were analyzed in soils collected from 57 sites. The concentrations of PCDD/Fs ranged from 0.06 to 10.43 pg WHO-TEQ /g d.w (mean value, 1.35 pg WHO-TEQ /g), and the concentrations of DL-PCBs ranged from ND to 3.50 pg WHO-TEQ /g d.w (mean value, 0.97 pg WHO-TEQ/ g). The TEQ concentrations were as follow: industrial area > rural area > suburban area > urban area. In terms of congener distribution, OCDD was predominant congener with the various fraction (from 27 to 84%). The ratio of PCDF to PCDD ranged from 0.06 to 1.25. POPs were analyzed in surface sediments and river water collected from each 30 and 36 sites, respectively. The concentrations of PCDD/Fs ranged from 0,001 to 3.828 pg WHO-TEQ/g (mean value, 0.860 pg WHO-TEQ/g) in surface sediment. In river water, the concentrations of PCDD/F ranged from 0,002 to 0.966 pg WHO-TEQ/L (mean value, 0.095 pg WHO-TEQ/L). Backward trajectories was conducted to show the pathways of air particles using HYSPLIT4 (Hybrid Single Particle Lagrangian Integrated Trajectory, Version 4) model with FNL meteorological data. In this study, the movement pathways of local or regional pollutants were estimated at 50m AGL within the surface layer. 72 hours backward trajectories were computed each hour, from noon to noon, starting at 50m AGL. This study was completed in order to investigate the equilibrium of PCDD/Fs in air and soil, and to know whether soil is a secondary source of PCDD/Fs pollution in air. The relationship between molecular weight, vapor pressure(PL) and octanol-air partition coefficient (Kow) to the PCDD/Fs concentration of air(Cair) and soil(Csoil) were unclear. The slope of the regression line between soil-air partition coefficient (Ksa) and scavenging coefficient (Csoil/Cair) ranged from 0.202 to 2.1462, and the PCDD/Fs concentration between air and soil did not reached to the equilibrium state. The soil/air fugacity quotients (fsoil/fair) of low chlorinated compounds (2,3,7,8-TCDD, 2,3,7,8,-TCDF, 1,2,3,7,8-PeCDF and 2,3,4,7,8-PeCDF), were less than 1, while fsoil/fair of high chlorinated compounds were (1,2,3,7,8,9-HxCDD, 1,2,3,4,6,7,8-HpCDD and OCDD, OCDF) were greater than 1. Such result is highly effected by the deposition of PCDD/Fs from air to soil.

Key words: PCDD/Fs, DL-PCBs, OCPs, PCA, Fugacity