Congener profiles and source-wise phase partitioning analysis of PCDDs/Fs and PCBs in Gyeonggi-do ambient air, South Korea.

Jongwon Heo,Gangwoong Lee,Donggi Kim

doi:10.3390/ijerph111111065

Abstract

The atmospheric concentrations and gas–particle partitioning of polychlorinated dibenzo-p-dioxins and furans (PCDDs/Fs) and polychlorinated biphenyls (PCBs) were investigated at two sites (Suwon and Ansan) in Gyeonggi-do, a heavily industrialized area of Korea, during the year 2010. The sum level (Σ17) of PCDDs/Fs and dioxin-like PCBs (dl-PCBs) in the ambient air at Suwon and Ansan ranged from 0.04 to 0.30 pg-TEQ·m−3 (geometric mean: 0.09 pg-TEQ·m−3) and 0.17 to 0.63 pg-TEQ·m−3 (geometric mean: 0.36 pg-TEQ·m−3), respectively. Moreover, the geometric mean concentrations of Σ180 PCBs at Suwon and Ansan were 233.6 pg·m−3 and 274.2 pg·m−3, respectively, and di-chlorinated biphenyls and tri-chlorinated biphenyls were the predominant homologs. Among the PCB congeners, 3,3'-dichlorobiphenyl (PCB-11) was the dominant species at both sites during all sampling periods, comprising up to 15.1% of Σ180 PCBs at Ansan and 24.6% at Suwon. We evaluated their gas-to-particle equilibriums by conducting regression between the particle–gas partition coefficient Kp (m3·ug−1) and the corresponding subcooled liquid vapor pressure (PL°). The slope (m) values for log–log plots of Kp vs. PL° were steeper in industrial areas owing to local source proximity. Moreover, owing to enhanced emissions from combustion-related sources at low temperatures, PCDD/Fs exhibited the largest deviation from the regression line of the particle–gas partition coefficient. Incinerators were found to be the primary emission source of atmospheric PCDDs/Fs, whereas re-evaporation from pre-existing environmental loads (e.g., storage areas or spilled soil and water bodies) was the dominant source for PCBs.

Highlights

Polychlorinated biphenyls (PCBs) were first synthesized by Schmidt and Shultz [1], and have been used widely in industrial applications since the 1920s owing to their chemical stability, including their high heat resistance and nonflammability [2,3]
The toxic equivalent quantity (TEQ) value for PCDDs/Fs obtained from the International Toxic Equivalent Factors (I-TEF) and TEQ
Among the major congeners, PCB-155 (HexaCB), 184 (HeptaCB), 209 (DecaCB) were found to be enriched at AS relative to SW. These results indicate that high molecular weight (HMW) PCBs are likely to remain in the vicinity of local sources, whereas low molecular weight (LMW) PCBs are more likely to be transported over long ranges [43]

Summary

Introduction

Polychlorinated biphenyls (PCBs) were first synthesized by Schmidt and Shultz [1], and have been used widely in industrial applications since the 1920s owing to their chemical stability, including their high heat resistance and nonflammability [2,3]. They have been used in electrical equipment, as dielectric fluids in capacitors and transformers, over the past 50 years. PCDDs/Fs are highly toxic and persistent when released into the environment through combustion processes associated with the production of chlorinated chemicals; incinerators represent an important source of PCDD/Fs pollution in Korea [5,6].

Methods

Results

Conclusion