|Other Abstract||With the fast development of industry and agriculture，the industrial sewage, without treatment or with improper treatment, had been massively discharged into water bodies. The incomplete combustion products of the fuel, such as the coal and petroleum, and the virulent noxious gas from the chemical industry and kinds of vehicles being discharged into the atmosphere, as well as the agricultural chemicals fertilized by farmland, had been entered into water bodies through the atmospheric subsidence and the surface runing off, and stored in the sediment for a long time, heavily harming the aquatic ecological structure and human health. The toxicity of those persistent organic pollutants （POPs） only with the ppb or ppt magnitude in water bodies or even more lowerly, was very big in physiological and ecological aspect. The conventional monitor parameter such as BOD, COD, cannot reflect the pollution levels of POPs in water bodies, so it is the important component of the environmental pollution controlment to carry on the research on POPs in water bodies. Wuhan，with so many lakes, is located at the connect with Yangtze River and Hanshui River. The area of lakes is approximately 1/4 of the city total area and so is known as the city with the most urban lakes in China. The water pollution and the eutrophication are the main environment questions in Wuhan urban lakes at present. The water quality was mainly of class III and IV, no class I and few lakes belonged to class II. Formerly, the research on urban lakes’ pollution was carried mainly about the eutrophication, while the reports about studies on the POPs was so less.
This article has discussed the POPs in 16 lakes belonging to four urban lake systems in Wuhan and showed the degree of artificialiy organic pollutants. The main results were shown as follows:
1．The study has examined the content of 25 POPs in four lake systems using the mix external standard. Most of 25 POPs were present except pentachlorophenol, hexachlorocyclopentadiene, which were too low to be detected in all water, SPM, and sediment samples from the studying locations. Among of them, the content of phthalates was obviously higher than the other kinds, and the content of PAHs, PNBs and isophoron was relatively lower. The main resources of organic pollutants in urban lakes were industrial wastewater and municipal sewage，thus the content of phthalates was the highest.
2．Comparing the total contents of 25 POPs in four lake systems, the results showed the tendengcy as Dongshahu lake system> Tangxunhu lake system> Donghu lake system in Hanyang district>Beihu lake syetem, only except in Tangxunhu lake system. The contents of 25 POPs in SPM and in the surface sediment samples from Tangxunhu lake system were lower than those from Donghu lake system in Hanyang district, while the contents in the subsediment layer and in the deep sediment layer samples were the highest. In Donghu lake system in Hanyang district, the tendency of the total contents of 25 POPs was Nantaizihu lake> Moshuihu lake and Yuehu lake > Sanjiaohu lake > Houguanhu lake, and the tendency in Dongshahu lake system was Shahu lake> Donghu lake (Shuiguohu lake > Guozhenghu lake > Tanglinghu lake> Niuchaohu lake > Yujiahu lake >Houhu lake) > Xiaotanhu lake > Yangchunhu lake, and the tendency in Tangxunhu lake system was Nanhu lake> Tangxunhu lake> Huangjiahu lake and Qinglinghu lake > Yehu lake, and it in Beihu lake syetem was Yanxihu lake> Yandonghu lake. The results showed the pollution degree related heavily with the source of pollutants. The content of POPs in the locations near to the urban center and industrial district was higher and the pollutant degree was relatively more serious, because of lots of effluents of industrial waste and municipal sewage. While the content was lower and the pollutant degree was relatively lighter in the locations far away from the urban center and the industrial district.
3．The concentration factor of POPs from water to the suspended particulate matter (SPM) sample was larger，and the concentration factor from SPM to the surface sediment was close to 1. The content from the subsediment layer and the deep sediment layer samples were slightly higher. The concentration factor from various lakes was slightly different. It showed POPs from lake systems were deposited mainly the last half century.
4．Di-n-butyl phthalate (DBP) and bis(2-ehtylhexyl)phthalate (DEHP) have been used most largely of phthalates in the plasticizer, the content of which obviously was higher than other kinds of POPs in major samples. Their contents has accounted 10%-99% of 25 POPs, and then they were the main pollutants in lake systems. The content of DBP，in Dongshahu lake system with the mean of 9100.48ng/l and in Tangxunhu lake system with the mean of 6185.13ng/ L，exceeded the national surface water standard GB3838-2002（3000ng/ L）.
5．The concentration of PAHs in the subsediment layer was highest, and the next was the deep sediment layer and the surface sediment samples, while the concentration in SPM and water appeared correlatively lower. The range of the content in water was large. The solubility of PAHs in the water bodies was small, and PAHs in water generally deposited through the adsorption on the suspended particle, therefore the content of PAHs in sediment samples was somewhat high. Among of them, the concentration of BAP in the surface sediment and SPM was the highest, and the next was that in the subsediment layer and in the deep sediment layer samples, while the lowest was that in water. The content of BAP，in Shahu Lake（6.72-8.81ng/L），in Tangxunhu Lake（0.36-10.89ng/ L）and in Nanhu Lake（1.10-4.31ng/ L），exceeded the national surface water standard GB3838-2002 （2.8ng/l）. The ratio of BaA/ (BaA+Chr) in most of locations was nearly 0.5, and it possiblly has the dual pollution sources of PAHs in these urban lakes. The main source might be dischargeed into water bodies from the fossil fuel high-intensity combustion pollutants and the industrial waste gas and waste effluents. The ratio of BaA/Chrysene changed from 0.02 to 52.24 in samples. It indicated the PAHs route of transmission was shorter in the seriously polluted lakes, while longer somewhat in the lightly polluted lakes. PAHs, related mainly of nearby urban lives and the industrial waste discharging through the long distance migration, has possibilly created the lake system pollution.
6．The content of PNBs was not high in the overwhelming major location. It was relatively higher in water and SPM samples, and the concentration factor was small. The point pollutant source might be discharged into the lakes in the collecting sample period. The content in the surface sediment was small, showing in the recent years less PNBs into lakes. The content in the subsediment layer and the deep sediment layer increased sharply, indicating lake systems once had massive sources of PNBs pollutants dispersed into lakes. Among of them，the content of 2，4-Dinitrobenzenen in some locations of Donghu Lake（22.17-736.33ng/l），exceeded the national surface water standard GB3838-2002（300ng/l）. The main PNBs pollution originated possibly the industry nearby and the hospital and so on.
7．The content of isophoron，accounting 25 POPs total concentrations of n.d.~16.74%， was not high. Hexachlorobenzene was presented in some location of Yuehu lake, Moshuihu Lake, Yangchunhu Lake and Donghu Lake, relating possiblely with long ago discharging massive waste water directly into water bodies, the medical trash and the solid reject burning, and the sludge burning and so on.
8．In brief，the content of POPs in lake systems in Wuhan was small，while some POPs exceeded or close to the national surface water standard in some locations of Donghu Lake，Shahu Lake，Tangxunhu Lake，Nanhu Lake and Huangjiahu Lake. This status should bring into attention.|