| The dissertation focuses on the Gaoantun waste incineration plant industrial area as the research object in Beijing, and takes PBDEs in multiple environmental media as research target. PBDEs pollution status, distribution characteristics, and its migration behavior in media that caused by the incinerator are studied.Research shows that, near the incinerator, 42 analogues of PBDEs are detected in gas, particulate matter, soil, plant roots, stems, and leaves. ∑42PBDEs content range and mean value(dry weight) in the atmosphere(gas phase + particulate matter), soil, and plants are 207~829 pg·m-3, 522 pg·m-3; 32.5~117 ng·g-1, 66.1 ng·g-1; 1.71~34.4 ng·g-1, 9.89 ng·g-1 respectively. As compared with other regions at home and abroad, the pollution levels of PBDEs are little higher than medium. Using the principal component analysis, correlation analysis of concentration distribution and distance from the sampling point to incinerator, these analysis results show that the incinerator is a major source of PBDEs pollution.Distribution and concentration of PBDEs in gas-particle is higher in winter than in summer. The change of PBDEs concentration in different plants is shown as Abutilon theophrasti > Endive > Calystegia > Dandelion > Goosefoots > Amaranth > Kochia scoparia > Chenopodium serotinum > Otentilla > Morning glory. At the same point of the vertical space, the variation trend of PBDEs concentration is soil > root > stem, more total suspended particles than gaseous medium. In the horizontal space, taking incinerators as center, radius is in the range of 5km, concentration of PBDEs in environmental media showed the trend that the farther from incinerators, the lower the concentration.Study on the migration transformation rule of PBDEs in multimedia shows that, during garbage disposal process in the incinerator, the discharged PBDEs is distributed in gas and particulate matter in a temporary balance condition for the first time. Then enter into the atmosphere, diffusion, drift, and sedimentation. Under the influence of many factors, such as temperature, vapor pressure, atmospheric particles, and organic matter, etc., gas-particle distribution run out of balance. The high brominated analogues are degraded during the process of migration and sedimentation, and their abundances have changed. The abundances of low brominated analogues have increased, and migrate further. The abundances of high brominated analogues are decreased. Meanwhile, PBDEs that contained in part of particles are accumulated in soil after sedimentation. Soil is the “source” of root absorption of PBDEs, which are conducted from root to stem, then enter into leaves during the process of plant metabolism and photosynthesis. In addition to the supply from the stem, PBDEs in leaves are coming from external environment such as gas or sediment particle that carry PBDEs, which enter into leaves under action of photosynthesis and Van der Waals force. Besides, during the transfer process of PBDEs from soil to root, and to stem and final to the leaf, low brominated congeners showed higher migrational ability than the high brominated congeners.Assessment of ecological risk indicates that cancer risk of PBDEs in soil and atmosphere, near and around waste incineration plant to the local residents is far lower than the minimum reference value of the United States environmental protection agency’s risk of cancer health evaluation standard. As for plant, it can bring potential hazards to the health of the local residents if they eat plenty of edible amaranth for a long time.Based on the analysis of PBDEs migration and transformation mechanism in atmosphere(PM2.5, PM10, TSP, PUF), soil, plants(root, stem and leaf), and the correlation among multiple media, plant organs with high sensitivity to PBDEs have been preliminarily selected. What’s more, the scientificity of using the plant organs as bio-indicator is demonstrated by PBDEs environmental concentration difference. Results show that amaranth can be taken as a bio-indicator. |
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