东莞市土壤中多环芳烃的含量、代表物及其来源

CONCENTRATION, INDICATORS, AND ORIGIN OF POLYCYCLIC AROMATIC HYDROCARBONS IN THE SURFACE SOIL IN DONGGUAN

2002年10～12月采集东莞市各地土壤样品64个,采用气相色谱-质谱仪对土壤中的16种优先控制的多环芳烃(PAHs)进行分析.结果显示,东莞市土壤中16种PAHs平均含量413μg/kg,含量较高的几种组分分别是菲、萤蒽、屈、苯并[b]萤蒽、芘.与PAHs总含量相关性较好的7种组分分别为屈、苯并[a]蒽、苯并[b]萤蒽、苯并[k]萤蒽、苯并[a]芘、茚并[1,2,3]芘、二苯并[a,h]蒽;所有相关系数R2均超过0.9000,可作为东莞市土壤中PAHs的代表物.北部平原水乡的PAHs污染明显高于南部丘陵山区、水乡上游保护区以及中部过渡带.化石燃料高温燃烧产物的大气沉降为东莞市土壤中PAHs的主要来源.东莞市农业土壤中PAHs含量显著低于天津市受污染严重的农业土壤.

Surface soil samples (0~20 cm) were collected from Dongguan in October ~ December 2002 and analyzed with GC/MS for 16 kinds of polycyclic aromatic hydrocarbons (PAHs) listed for priority control. The average concentration of the 16 in samples was 413 μg/kg. Among the 16, phenanthrene, fluoranthene, chrysene, benzo(b)fluoranthene and pyrene were relatively higher in concentration in the soil, and seven (chrysene, Benz[a]anthracene, benzo[b]fluoranthene, benzo[k]fluorathene, indeno(1, 2, 3-cd)pyre, benzo[a]pyrene,and dibenzo (a, h) anthrace) showed a better linear relationship with the total amount of PAHs thus being the indicators of PAHs pollution of soils. The PAHs pollution was obviously more serious of the plain area in the North than the hilly region in the South, transitional region in the Central area and the nature reserve in the upper streams of the Watery region. The PAHs in the surface soil of Dongguan came mainly from burning of fossil fuel in the form of atmospheric deposition over long distances. The contents of PAHs in Dongguan agricultural soils were obviously lower than in the agricultural soils of heavily polluted Tianjin.