The Residues And Environmental Risks Of Multiple Veterinary Antibiotics In 34 Swine Livestock In 15 Provinces Of China

The accumulation of antibiotics in the environment can lead to environmental pollution,ecotoxicity,and infectious diseases caused by antimicrobial resistant pathogens through the food chain.At present,there is no comprehensive report on the antibiotic residue characteristics and risks assessment in swine livestock.Therefore,this study aims to explore the residual characteristics and the risk of antibiotics in swine livestock using liquid chromatography-tandem mass spectrometry(LC-MS/MS).The method of multi-residue detection established in our laboratory was used to determine the residues of antibiotics in the feces,soil,sewage and vegetable samples in the farm.The main types of antibiotics include: tetracyclines,sulfonamides,macrolides,fluoroquinolones,lincosamides,and pleuromutilin.The samples were collected from the following provinces mainly: Zhejiang,Jiangsu,Jiangxi,and other 12 provinces.A total of 893 samples were tested,including 549 swine manure samples,190 soil samples,109 sewage samples,and 45 vegetable samples.The results showed that the antibiotics were i)excreted into the environment through swine manure;ii)remained in the surrounding environment widely and highly concentrated;iii)the residual concentrations of samples from different sources were quite different.The most serious antibiotic residue in swine manure were chlortetracycline,oxytetracycline,tetracycline,doxycycline and tilmicosin.The detection rate was 64.1%～83.4%,and the average residual concentration was 2221.7～10136.5.μg/kg The most serious antibiotic residue in soil were: tetracycline,chlortetracycline,tilmicosin,oxytetracycline,and doxycycline.The detection rate was between 59.7% and 79.6%,and the average residual concentration was 237.7～3611.6 μg/kg.Among the sewage samples,the most serious antibiotics were oxytetracycline,tilmicosin,chlortetracycline,ciprofloxacin and doxycycline,and the detection rate was between 52.3% and 71.6%.The concentration is between 117.0～12737 ng/L.Among the vegetable samples,the most serious antibiotics were oxytetracycline,tetracycline,chlortetracycline,enrofloxacin,and tilmicosin.The detection rate was between 44.2% and 90.7%,and the average residual concentration was 34.0.～229.2 μg/kg.The risk quotient method was calculated to assess the risk of residues in soil and sewage.The results showed that the tetracycline had the highest ecological risk,and its RQ was up to 3584 in the sewage and reaching 1621 in the soil.This study reveals that the residue of antibiotics in swine livestock environment in China is very serious.It is highly suggested that the use of antibiotics on livestock should be strengthen and the use of antibiotics on farms or as promote antibiotic substitutes should be prohibited.