Ambient air concentrations of PCDD/Fs, coplanar PCBs, PBDD/Fs, and PBDEs and their impacts on vegetation and soil

The impact of persistent organic pollutant (POP) concentration in ambient air on vegetation and soil is investigated in the present study. Ambient air, vegetation, and soil samples were collected from the vicinity of an industrial complex. For each collected sample, the polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs), coplanar polychlorinated biphenyls (coplanar PCBs), brominated dibenzo-p-dioxins/dibenzofurans (PBDD/Fs), and polybrominated diphenyl ethers (PBDEs) concentrations were analyzed. Principal component analysis (PCA) was adopted to explore the relationships between the concentration of each POP type in ambient air with those in soil and vegetation. Results show that particle-phase PCDD/Fs, PBDD/Fs, and PBDEs, respectively, account for 60.6, 98.3, and 75.7 % of the total concentration in the air, which are much higher than that of coplanar PCB (5.2 %). Results obtained by PCA suggest that PCDD/Fs in vegetation are contributed by atmospheric gas-phase PCDD/Fs, whereas in soil they are contributed by particle-phase PCDD/Fs. Coplanar PCBs concentrations in both vegetation and soil are contributed by atmospheric gas-phase coplanar PCBs. PBDD/Fs concentrations are both contributed by particle phase. PBDEs in vegetation are contributed by both gas- and particle-phase PBDEs, while soil PBDEs are contributed mainly by the particle phase. In confirmation of these results, the researchers found that the above results are consistent with those obtained from theoretical calculations and previous studies. Therefore, it is concluded that the results obtained from the present study would provide useful information for assessing the fate of ambient air POP concentration.

Keywords
Ambient air; Vegetation; Soil; Persistent organic pollutants (POPs); Gas phase; Particle phase