The Content、Distribution And Pollution Assessment Of Pb In Latosol Of Hainan Island

In recent years, the rapid development of industrialization, urbanization,mine mining,smelting, irrational usage of pesticides, fertilizer and plastic sheeting all resulted in a largenumber of pollutions that was dropped into the soil environment, which caused the soilecological environment quality in a recession tendency and caused the heavy metal Pbcontamination in the soil is very serious. Obviously it has become a serious problem for thewhole world. This article chooses the typical zonal soil-the latosol of Hainan as the researchobject. We take field sampling and utilize ICP-MS as the main way of analying all the data, inthe study area Pb in soil samples of content, soluble content and plant samples of Pb contentwere analyzed, the results were showed as follows:（1）In Hainan Island, The Pb content ranges from1.73to445.18μg/g in Latosol, meancontent of39.99μg/g which is higher than it’s soil background values（19.69μg/g）. In HainanIsland, The Pb soluble content ranges from0.19to18.95μg/g, mean soluble content is3.60μg/g; The Pb soluble percentage for the ranges from1.26to35.85%, mean solublepercentage is8.60%.（2）The mean content of Pb in different parent materials are as follows: Granite laterite(46.51μg/g)>Sandshale laterite (43.92μg/g)> Arenaceous-pelite laterite (31.38μg/g)>Shallow laterite (26.24μg/g)> Basalt laterite(19.39μg/g). The mean soluble content of Pb indifferent parent materials are as follows: Basalt laterite (6.41μg/g)>Sandshale laterite(3.85μg/g)>Granite laterite (3.78μg/g)> Arenaceous-pelite laterite (3.52μg/g)> shallow laterite(1.33μg/g).（3）On the horizontal space, the mean content of Pb in the study area relate to latosoldifferentiation rules are as follows: Low hill (55.69μg/g)> Central mountain (49.78μg/g)>mesa plain (30.05μg/g); The mean content of water-soluble state latosol about Pb elementdifferentiation rules are as follows:Low hill (4.94μg/g)> Central mountain (4.26μg/g)> mesaplain (2.43μg/g), it’s horizontal space are as like as the level on the mean of differentiationconcerning the law in line.（4）On the vertical space, the distribution of Pb in the Sandshale laterite layers that themean content of layer C (55.31μg/g)> layer B (44.86μg/g)> layer A (35.12μg/g),whichenriched in the parent material; The same situation for Sandshale laterite andArenaceous-pelite laterite layer soluble mean content is that as follows: the highest is layer C,then layer B, layer A followed behind. In the Basalt latosol of Pb layer A (25.45μg/g)>layer B (18.76μg/g)> layer C (13.90μg/g), which enriched in the leached layer; soluble Pb layer A(8.83μg/g)> layer B(6.97μg/g)>layer C (0.47μg/g).In the shallow laterite of Pb:layerB(31.00μg/g)> layer A (20.99μg/g); soluble Pb layerB (1.36μg/g)>layer A (1.30μg/g).In theArenaceous-pelite laterite and granite laterite of Pb, the highest is layer B, then layer C, layerA followed behind; Pb in the Variation of Granite laterite layer soluble mean content are asfollows: layer B (3.94μg/g)> layer A (3.93μg/g)>layer C (3.44μg/g).（5）The cumulative rules of Pb in coastal sand Casuarina root, branche，leave are asfollows:Casuarina leave (7.60μg/g)>Casuarina branche (5.11μg/g)>Casuarina root (4.85μg/g),which enriched in its leaves, branches and roots are relatively small.（6）Compared with the National Soil Environmental Quality Standard values, thesample point of the study area, only the Lingkou town,Zhongsha town,Cha river (92.88μg/gand120.86μg/g) in the hilly and Vacation cottage,Xishui town, Peace Town in the centralmountains etc.7samples exceeded the National Soil Environmental Quality Standard values,the value of the other sample points lower than the national standards in the critical value.（7）The results of the evaluation of the application of a single pollution index: only inthe hilly that Lingkou town, Zhongsha town, Cha River (Pi=1.16, Pi=1.51) and theVacation cottage, Xishui town, Peace town in the central mountain, such as the7samplesperformance of light pollution, accounting for6.73%; The rest of the sample non-polluting,accounting for93.27%, cleanliness is high.（8）The application of Geoaccumulation index evaluation shows that:48sample pointsis Non-polluting, accounting for46.15%of the total sample points; The Jiaji town etc.46sample points range from light pollution to medium pollution; The Leguang farm etc.8samples express medium pollution; The esat of Lingkou town, Cha river2samplesperformance for a moderate-strong pollution; It is relatively common in the study area thatsoil Pb pollution, contaminated proportion reached53.85%, So the relevant departmentsshould carry out the basic requirments about Pb Pollution prevention which actually should bebased on the actual situation.