| Antibiotics have good antibacterial activity and low price,so they are widely used in human medical,livestock and aquaculture industries.Due to antibiotics can infiltrate into environmental water through surface runoff and medical waste,different kinds of antibiotics have been detected in surface water,groundwater,domestic sewage and drinking water,etc.At present,different kinds of antibiotics have been detected in different water bodies,such as surface water,groundwater,domestic sewage and drinking water.The phenomenon that a large number of antibiotics exist in the water environment has attracted the attention of many countries all over the world.China is a big country in the production and use of antibiotics,but research on antibiotics in aquatic environment started too late.At the same time,our country has the characteristics of vast land area,large population and so on.The situation of antibiotic pollution in water environment is more complicated than that in foreign countries.The Dianshan Lake is the largest natural freshwater lake in Shanghai and an important water conservation area in the upper reaches of the Huangpu River.In recent ten years,Dianshan Lake has occurred environmental pollution events frequently,and also has serious ecological problems with the continuous development of Dianshan Lake around the lake to promote urbanization.At present,there are few researches on antibiotic multi-medium pollution study,source analysis and risk assessment in Dianshan Lake.In this study,we studied 20 typical antibiotics in Dianshan Lake systematically and collected 3 kind of samples including surface water,sediment and aquatic plants in Dianshan Lake,and the seasonal and spatial of these20 characteristic antibiotics in Dianshan Lake were analyzed,as well as their the source and the level of risk.The results are as follows:?1?Antibiotic contamination characteristics in surface water of Dianshan Lake:there were 20 antibiotics in surface water,the change rate of monomer was 21%100%,the average detection rate was 60.5%.The antibiotic concentration showed obvious seasonal difference,the concentration characteristics of 20 antibiotics in geometric mean value were as follows:spring?49.52 ng/L?>autumn?20.38 ng/L?>summer?14.47 ng/L??winter?12.26 ng/L?.The concentration of antibiotics in the water is about the spatial distribution of the entrance>exit>body.In spring,the concentration of antibiotics in Baishiji was much higher than that in other inlets.The concentration of antibiotics at 600 ng/L.H5 point appeared abnormal high value,which might be related to the density of residents and aquaculture.Compared with other rivers and lakes,the level of antibiotic pollution in surface water of Dianshan Lake is moderate.It is necessary to strengthen the management of the high polluted area such as Baishiji part and Lanlu harbor.Both of them belong to living area.?2?The detection ratio of five kinds of target antibiotics was 75%in 14 sampling points in the sediments of Dianshan Lake.Among them,antibiotics including chlortetracycline,roxithromycin,sulfamethazine,and norfloxacin,were not detected in any seasons.The detection rates of erythromycin,sulfaquinoline and sulfathiazole are 100%in four seasons.The seasonal variation is consistent with that of surface water,showing spring?580.87ng/g?>autumn?358.85ng/g?>summer?64.2ng/g??winter?59.64ng/g?.The spatial distribution of chloramphenicol,sulfamethane and quinolones showed resemblance in four seasons,presenting the characteristics of entrancemouthand body of the lake.High concentrations of sulfonamides were detected in the center of lake H2 and H7,which were 108.09 ng/g and 67.77 ng/g respectively.The concentration of chloramphenicol in the center of lake H4 was the highest?3.06 ng/g?.The other points have no obvious spatial variation characteristics,and the concentration range is between 0.34 ng/g and 0.60 ng/g.?3?Lastly,study of antibiotic contamination of the dominant plant water hyacinth in Dianshan Lake.There were significant differences in the content and composition of antibiotics between root and non-root of water hyacinth.The total concentration of sulfonamides in roots was the highest,reaching 204.64 ng/g,accounting for 82.25%of the total antibiotics.Root antibiotic concentration ranged from 0.21 to 111.57 ng/g,The average values of the five antibiotics were sulfonamides?25.58 ng/g?>quinolones?4.40 ng/g?>tetracyclines?0.57 ng/g?>chloramphenicol?0.34 ng/g?>macrocyclic esters?0.21 ng/g?.The total concentration of quinolones in non-roots was the highest with a concentration of 124.04 ng/g,which accounted for 85.60%of the total antibiotic content.Non-root antibiotic concentration ranged from 0.19 to 68.95 ng/g,The average values of five kinds of antibiotics were quinolones?15.50 ng/g?>sulfonamides?0.94 ng/g?>tetracyclines?0.76 ng/g?>chloramphenicol>?0.71 ng/g?>macrocyclic esters?0.21 ng/g?.The main reason for this result is that sulfonamides can be adsorbed on the root of hyacinth to be degraded in the leaf tissue of the plant.Antibiotics in Dianshan Lake did not cause bioaccumulation to water hyacinth.?4?Analysis of the source of antibiotics in surface water,sediment and hyacinth of Dianshan Lake by principal component-multivariate linear regression.The results showed that antibiotics in the surface water were mainly derived from the discharge of animal husbandry wastewater,aquaculture,pharmaceutical pollution and household pollution,and their relative contribution rates were 53.07%,24.30%,15.00%and 7.63%.The main source of antibiotics in sediment comes from household water,animal husbandry,medical wastewater and sewage treatment plant,the contribution rate is 61.96%,20.82%,15.53%and 1.69%.The main source of antibiotics is water hyacinth comes from livestock and poultry feces pollution,fishery farming and medical waste water.The relative contribution rates were 79.13%,11.24%and 9.95%.?5?The risk grade assessment and health risk assessment of surface water,sediment and water hyacinth in Dianshan Lake are carried out by using risk quotient method and non-carcinogen model to calculate the average health hazard risk of human body through drinking water route.All samples in sediment and surface water shows low-risk or no-risk except for extended quinolones antibiotics.Quinolones and sulfonamides present a high risk to water hyacinth.The risk quotient of CFC in surface water is 1.808,the risk quotient of EFC in sediment is 2.626,the risk sulfonamides of ST in water hyacinth is 1.731,the risk quotient of CFC in hyacinth is2.440?RQ>1?.The health risk assessment of surface water shows that the non-carcinogenic risk of 11 antibiotics to human body ranged from 5.87×10-9to6.57×10-4a-1,and the total health risk of 14 samples of antibiotics is2.63×10-58.30×10-4a-1.Higher than the Netherlands construction and environmental release of the minimum negligible risk level(1×10-8a-1)three quantitative levels. |
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