Contents And Sources Of Polycyclic Aromatic Hydrocarbons In Vegetable And Soil Of Nanning City,China

Polycyclic Aromatic Hydrocarbons(PAHs)is one kind of toxic POPs and widely distributed in the air,soil and water.PAHs in the nature can spread with the circulation of water and air.PAHs as a kind of toxic POPs can be absorbed and enriched by plants and then pose a threat to our lives and environment.Nanning city as an example was choosed to monitor the 16 kinds PAHs in the soil and vegetable,which was listed by U.S.EPA,to research the pollution characteristics,laws and the sources of PAHs.With the collection of soil and vegetable samples from 4 traditional vegetable bases(Guangxi University,Na Ma,Wu Tang and Shuang Qiao)in the suburb of Nanning,16 kinds of polycyclic aromatic hydrocarbons(PAHs),which are on the list of priority control PAHs that stated by U.S.EPA,are analyzed in the way of HPLC.The research can help people to learn and understand the PAHs pollution in the soil and vegetable of Nanning City,on the other hand,it can also provide the data and information of PAHs in the environment of Nanning City for the researcher who wants to make a study of Nanning’s PAHs pollution.After analyzing the data of PAHs in the samples,the following results were obtained:1.The content of PAHs in the soil of Nanning ranges 2 632.00-5 002.43μg·kg-1 with the average of 3 351.30±1 110.72μg·kg-1,which presents a Serious Level of pollution.The level of PAHs pollution is Medium on the high side when compared with other area.2.Seen from the component characteristics,the PAHs in 2-4 rings,among the total,accounts for 85.72%,of which the PAHs in 3 rings occupies the biggest part(54.62%).3.Analyzing the sourses of PAHs in the vegetable soil in Nanning City by the method which rely on the ratio of molecular markers,the result shows that the sources of PAHs of these bases are mainly originated from the emission of automobile exhaust and the burning of fossil fuel.4.The PAHs which were on the list of U.S.EPA priority were all detected in the 5 kinds of vegetable of Nanning City.The ∑PAHs content in the 4 bases from high to low are:Na Ma>Guangxi University>Wu Tang>Shuang Qiao.5.∑PAHs content in vegetable of Nanning City has obvious change trend of the seasons,The ∑PAHs content in the 4 seasons from high to low are:February(winter)>December(autumn)>May(spring)>August(summer).6.∑PAHs content in the 5 kinds of vegetable of Nanning City has obvious difference,The∑PAHs content in the 5 kinds of vegetable of Nanning City from high to low are:Vigna unguiculata>Momordica charantia L.>Capsicum annuum L.>Brassica campestris L.ssp.chinensis var.utilis Tsen et Lee>Raphanus sativus L.