Distribution Characteristics,source Analysis And Ecological Risk Of Typical Antibiotics In Village-scale Environment Of Cold Regions

In recent years,pharmaceutical and personal care products（PPCPs）have received worldwide attention.Antibiotics,as one kind of typical PPCPs,have the characteristics of high efficiency,broad spectrum and low price,which play an important role in the prevention and treatment of human and animal diseases.And as an accelerator for animal growth,they are widely used in livestock and poultry breeding,were widely detected in surface water,groundwater,sediments,soil and organisms in the world,which have negative impacts on ecosystems and human health.However,there are few studies on antibiotics in water and soil in village scale and remote areas.Six villages and five farms in cold regions were selected in this study.Six categories of 34 antibiotics including quinolones（QNs）,sulfonamides（SAs）,tetracyclines（TCs）,macrolides（MLs）,β-lactams（β-Ls）and chloramphenicols（CPs）were selected as the targets.Firstly,the occurrence characteristics of target antibiotics in various village-towns were revealed.Then,the output level migration path of antibiotics in multiple farms,and the concentrations in the surrounding environment were expounded.Finally,the main sources and ecological risk of antibiotics in selected village-towns were analyzed.Based on the species sensitivity distribution（SSDs）,the criterion continuous concentration of 13 commonly used antibiotics were deduced.The main results are as follows:（1）The occurrence of antibiotics in the environment of high-altitude villages-town:5 and 10 antibiotics were detected in the water and soil in Shenzha Town,with the concentration range of 0.01～11.26ng/L and ND～41.043ng/g,respectively.amoxicillin（AMX）and roxithromycin（RTM）are the dominant antibiotics.12 kinds of antibiotics were detected in the sediment,the concentration range was ND～56.38ng/g,RTM is the most abundant,and 8 antibiotics were detected in yak manure with the concentration level of 0.1～1ng/g.（2）The occurrence of antibiotics in the environment of high-latitude village-towns:9 and 4 antibiotics were detected in the water bodies of Fengyuan Village and Daling Village respectively,and the concentration ranges were ND～32.69ng/L and ND～1.20ng/L.The dominant species were sulfamethoxazole（SMX）and sulfachloropyridazine（SLD）,respectively.9 and 7 antibiotics were detected in the soil,and the concentrations were ND～2.47ng/g and ND～5.19ng/g,respectively,TCs and QNs are the dominant categories.（3）The input and output level of antibiotics in the farms:11 antibiotics were detected in the feed of Chicken Farm 1 and Chicken Farm 2,and the total concentration was 4.45ng/g and 10.88ng/g,respectively.Five antibiotics were detected in the artificially prepared chicken feed water of Chicken Farm 1,and the concentration of penicillin G（PG）was the highest（1051ng/L）.15 antibiotics were detected in the feed of Cattle Farm,with a total concentration of 1261.92ng/g.9 and 10 of antibiotics were detected in chicken manure of Chicken Farm 1 and Chicken Farm 2 respectively,with the total concentrations were 1889.41ng/g and 11447.03ng/g,and the dominant antibiotic was oxytetracycline（OTC,1545.97ng/g）and penicillin G（PG,10252ng/g）.4 and 10 antibiotics were detected in pig manures of Pig Farm 1 and Pig Farm 2,respectively,and the total concentrations were 251.57ng/g and 373.07ng/g respectively,and OTC,ciprofloxacin（CIP）and enrofloxacin（ENR）are dominant respectively.8 antibiotics were detected in cattle manure of Cattle Farm,with a total concentration of 338.48ng/g,ENR and CIP are the dominant antibiotics.（4）The occurrence of antibiotics in the water bodies around the farms:4～6antibiotics were detected in the water bodies of Goumen,Daling and Huangdi Villages in Chaoyang Town,and the concentration range of target antibiotics was ND～4.54ng/L,ND～4.3ng/L and ND～3.67ng/L,all with SAs（SLD and SMX）as the dominant categories.14 antibiotics were detected in the water bodies of the Sandabao Village,with the antibiotic content ranging from 0.16 to 25.11ng/L,and a total of 13 antibiotics were detected in the corresponding sediments with the content of 0.01～16.86ng/g.（5）The occurrence of antibiotics in the soil around the farms:28 and 25 antibiotics were detected in the soil around Chicken Farm 1 and Chicken Farm 2,and the concentration ranges were ND～79.51ng/g and 8.81～133.06ng/g,respectively,QNs and TCs are the most abundant.15 and 7 antibiotics were detected in the soil around Pig Farm1 and Pig Farm 2,respectively,with concentrations rang of ND～3.74ng/g and0.02～75.15ng/g,both of which were dominated by TCs and QNs.18 antibiotics were detected in the soil around the Cattle Farm with the concentration rang of ND～3.74ng/g,and the chlortetracycline（CTC）,CIP and PG are the dominant antibiotics.（6）The longitudinal occurrence of antibiotics:The total concentration of most antibiotics and each layer in the three soil profiles（P1～P3）near the farms decreased gradually,and the total concentration decreased by 87.2%,96.8%and 82.5%from the surface layer to the bottom layer of P1～P3,respectively.Some QNs,TCs and MLs also showed similar decreasing characteristics.（7）The main source of antibiotics in the environment of villages-towns:The domestic sewage discharge and excretion of farmed animals are the main sources of antibiotics in Shenzha Town.The antibiotics in the water bodies of Daling and Fengyuan villages mainly come from the discharge of household farming manure and the irregular treatment of human antibiotics.The antibiotics in the water bodies of Goumen Village come from the mixed input of domestic sewage and farming manure.Sewage discharge and domestic sewage input are the main sources of antibiotics in the nearby water.The antibiotics in the water near the Sandabao Village directly come from the open-air stacking of pig manure.Irregular animal excretion and domestic sewage discharge are the main sources of antibiotics in the soil of Shenzha Town.Manure returning to the field is the main source of antibiotics in the soil of Fengyuan and Daling Villages.The animal manure produced by the farm is the direct source of antibiotics in the surrounding soil.（8）The ecological risk of antibiotics:AMX in the water bodies of Shenzha Town has risk.The RQ of all antibiotics in the water bodies of Daling Village,Huangdi Village and Goumen Village is less than 0.01,and there is no potential ecological risk.PG in the water bodies of Fengyuan Village has high-risk,AMX and PG are high-risk antibiotics in the Sandabao Village.The RQ_max of RTM and trimethoprim（TMP）in the soil of Shenzha Town is a key risk factor.The high-risk antibiotics in the soil around Daling Village,Fengyuan Village and Pig Farm 1 are all TMP.the combined risk entropy(RQ_sum)showed that the waste receiving point>other points.Although most antibiotics do not have ecological risks,the combined risk when multiple antibiotics coexist is significantly increased.（9）The criterion continuous concentration of the selected antibiotics:The SSDs of13 antibiotics were constructed.The HC₅ of 13 antibiotics is 0.052～17.543μg/L,and the criterion continuous concentration are 0.017～5.848μg/L.The selection of distribution function and toxicity data will bring the uncertainty for the target SSDs.