我国主要地区表层沉积物中16种PAHs的污染特征

Pollution characteristics of the 16 kinds of PAHs in the surface sediments in China

为全面了解我国表层沉积物中多环芳烃（PAHs）污染状况,对近10年文献报道的105组数据进行整理归纳,分析了我国沉积物中16种PAHs污染水平、组成特征和空间分布特征。结果表明,我国主要地区表层沉积物中PAHs质量比范围为ND（未检出）-27 510 ng/g,均值和中位值分别为789.1 ng/g和477.0 ng/g,总体处于中度污染水平;其中,高相对分子质量PAHs占61.6%。按水体类型分,河湖沉积物中PAHs质量比中位值高于近海;按地域分,河湖沉积物中PAHs质量比中位值分布呈西部和北部偏高、东部和南部偏低的特点;近海沉积物中黄海PAHs质量比中位值偏高,其他海域相近。这主要与气候条件、能源消耗、产业结构和水动力学等因素有关。目前,我国沉积物中PAHs生态风险整体偏低,但局部地区污染严重,会对当地产生一定生态影响。

This paper is inclined to reveal the pollution characteristics of the polycyclic aromatic hydrocarbons（PAHs） in the surface sediment at home based on the 105 sets which have been done in the last10 years with a comprehensive review of the pollution level,the composition and spatial distribution of PAHs.The results of our report and investigation have shown that the total mass ratio of 16 kinds of PAHs in the surface sediments was found in a range from zero（not detected） to 27 510 ng/g.The mean and median values of PAHs mass ratio stand for 789.1 ng/g and 477.0 ng/g,which indicate that the poEution level of PAHs in China can be attributed to the middle level,whereas the PAHs with high molecular weight account for61.6%of the total PAHs.The median values of PAHs concentration in the sediments of lakes and rivers prove to be significantly higher than those in the coastal areas.And,more accurately speaking,the median values of PAHs concentration in the sediments of the corresponding rivers and lakes turn to be higher in the western and northern regions but lower in the southern and eastern regions.This appears much in common to the distribution pattern of PAHs in the soils.While the factors of climate,energy resource consumption and industrial structure should be responsible for the difference,the annual precipitation and river water runoff also account for main distribution of PAHs in the sediments of the river and lake water.What is more,the median value of PAHs concentration in the sediments of in the Yellow Sea is higher,and those in the other coastal areas are similar.In addition,the pollution source and the characteristic features of the sediments may also account for the difference.Therefore,it can be seen that the distribution pattern of PAHs in the sediments is mainly related to the energy consumption,the industrial structure,the climatic conditions and hydrodynamie features.Although the general ecological risk of PAHs in the sediments in China remains low,there are some seriously polluted areas to confront a lot of troubles in dealing with the higher risks of PAHs.