重庆开州区菜地土壤抗生素污染特征及潜在生态环境风险评估

Pollution Characteristics and Ecological Risk Assessment of Antibiotics in Vegetable Field in Kaizhou,Chongqing

农田土壤抗生素累积及其导致的生态风险已成为国内外研究的热点.采用调查问卷和实验分析相结合的方式,研究了重庆市开州区菜地土壤中四环素类、磺胺类、喹诺酮类、大环内酯类和氯霉素类这5类抗生素的赋存特征,分析了抗生素含量和土壤理化指标的相关性,并评估其潜在生态环境风险.结果表明,菜地土壤存在抗生素累积,五大类共18种抗生素被检出,且以四环素类和喹诺酮类抗生素为主.喹诺酮类抗生素检出率最高(15.38%~100%),其中氧氟沙星和诺氟沙星检出率达100%;四环素类抗生素含量最高(0~42.88μg·kg^(-1)),其中土霉素含量最高为42.88μg·kg^(-1).菜地土壤中抗生素总量为1.64~233.11μg·kg^(-1);其中,空心菜地(89.73μg·kg^(-1))>白菜地(32.53μg·kg^(-1))>辣椒地(32.16μg·kg^(-1))>西红柿地(32.13μg·kg^(-1))>黄瓜地(26.46μg·kg^(-1))>草地(7.32μg·kg^(-1)).相关性分析结果表明,土壤中总抗生素含量与有机肥施用量呈显著正相关关系(P<0.05),与土壤pH呈显著负相关关系(P<0.05);土壤中喹诺酮类和磺胺类抗生素含量和土壤含水量呈显著负相关关系(P<0.05),而喹诺酮类抗生素含量与土壤速效磷、有机质含量呈显著正相关关系(P<0.05).潜在生态环境风险评估结果显示:开州区菜地土壤中四环素类和喹诺酮类抗生素具有中度生态风险,其中62%~92%和62%~100%土样的喹诺酮类抗生素对土壤动物和微生物具有潜在毒性.

The accumulation of antibiotics in farmland and its ecological risk have become a research hotspot at home and abroad.The objective of this study was to investigate the occurrence and accumulation of antibiotics and their potential environmental and ecological risks in vegetable fields in Kaizhou district of Chongqing country.The occurrence characteristics of antibiotics including tetracyclines,sulfonamides,quinolones,macrolides,and chloramphenicols were detected using experimental analysis.The results showed that there was an accumulation of antibiotics in the vegetable soil,and 18 antibiotics in five categories were detected(0-42.88μg·kg^(-1)),mainly for tetracyclines and quinolones.The detection rate of quinolone antibiotics was the highest(15.38%-100%),especially for norfloxacin and ofloxacin(100%),whereas the tetracyclines presented the highest concentration(0-42.88μg·kg^(-1)).The amount of total antibiotics in the vegetable soil was 1.64-233.11μg·kg^(-1),whereas different vegetable soils showed the following trend:water spinach soil(89.73μg·kg^(-1))>cabbage soil(32.53μg·kg^(-1))>pepper soil(32.16μg·kg^(-1))>tomato soil(32.13μg·kg^(-1))>cucumber soil(26.46μg·kg^(-1))>grassland(7.32μg·kg^(-1)).The correlation results showed that there was a significantly positive correlation between total antibiotic residues and organic fertilizer application(P<0.05)but a significantly negative correlation with soil pH(P<0.05).Quinolones and sulfonamides were negatively correlated with soil water content(P<0.05),whereas quinolones positively correlated with soil available phosphorus and organic matter content(P<0.05).The potential eco-environmental risk assessment results showed that tetracyclines and quinolones in vegetable soil in Kaizhou district had certain ecological risks,of which 62%-92%and 62%-100%of soil samples with quinolones had potential toxicity to soil animals and microorganisms.