Component Characteristics Of PCBs In The Atmosphere And Soil Of Liaodong Bay Area

PCBs are typical persistent organic pollutants.The pollutions of PCBs presents regional and multi-medium characteristics,which pose latent threats to human health and the ecological security.PCBs have been used in Liaodong Bay area and the surrounding areas for a long time.At present,there is not enough information of the pollution conditions of PCBs in the environment of Liaodong Bay area,thus studies on the PCBs characteristics in the air and soil and the origins are important to evaluate the influence of PCBs to the Liaodong Bay area ecological environment security,the treatment method and the formulation of environmental policy.In 2006 and 2007,53 air samples and 33 soil samples were collected in Liaodong Bay area.Samples were pretreated and examined using the GC-ECD based on USEPA standards.The results indicated that:The average atmospheric concentration of∑PCBs in this area was 1267.47 pg/m~3,∑6PCBs was 112.62pg/m~3 and∑d1-PCBs was 30.00pg/m~3.Compared with other areas, the average concentration of∑PCBs in the area atmosphere was in the middle level.The south part of the area was in high level whereas the north and west were in middle.PCBs44 is the congener with the highest concentration of 741.61pg/m~3 in Liaodong Bay area.The rural concentration of∑PCBs in the atmosphere of Liaodong Bay area was 2303.17pg/m~3,which was in moderate levels of PCBs contaminations,and that in urban was 490.31pg/m~3,in low levels.PCBs congeners with 4 Cl atoms were 78.4%in the rural atmosphere,and congeners with less Cl atoms were equal in the urban atmosphere.The average concentration of∑PCBs in the soil was 15.97ng/g,∑6PCBs was 6.85 ng/g and∑d1-PCBs was 2.35ng/g.Compared with other areas,the average concentration of∑PCBs in the area soils was in the low level.Regions alone bay were all in low levels. The rural concentration of∑PCBs in the soil of Liaodong Bay area was 22.92ng/g,and that in urban was 11.10 ng/g,which were both in low levels.PCBs congeners with 4 Cl and 5Cl atoms were 41.22%and 32.24%in the rural soil,respectively.And congeners with 4 Cl atoms and more than 6 were 49.13%and 28.15%in the urban soil,respectively.By analyzing the characteristics of the relative distributions of dioxin-like PCBs and the characteristics of the relative distributions of PCBs with different C1 atoms,it comes to the conclusion that the type of PCBs pollution was Aroclor1242;and it was known that the source of PCBs was the Insulating oil in the Power Equipments that had the similar composition with Aroclor1242.A large number of the Power Equipments ever be used and being used in Liaoning Sino-South industrial base may be the main source of PCBs contamination in the atmosphere of Liaodong Bay area.