畜禽粪肥还田四环素类抗生素(TCs)在土壤-蔬菜系统的分布特征及风险评估

Distribution Characteristics and Risk Assessment of Tetracycline Antibiotics(TCs)in Soil-Vegetable System with Soil Fertilized with Animal Manure

畜禽粪肥还田引起的土壤抗生素污染对蔬菜安全和土壤生态风险的影响应得到足够的重视.四环素类抗生素(TCs)在畜禽粪肥和蔬菜基地土壤中被普遍检出且含量较高.然而,目前针对土壤TCs污染对蔬菜安全和土壤生态风险的研究主要采用盆栽试验和田间调查的研究方法,较少开展田间试验.结合盆栽试验和田间试验的研究方法,调查畜禽粪肥还田引起的TCs在土壤-蔬菜系统中的分布特征,采用日允许摄入量-危害商值法(ADI-HQ法)和物种敏感性分布-风险商值法(SSD-RQ法)分别对蔬菜可食部分TCs污染的人体健康风险和土壤TCs污染的生态风险进行评估.结果表明,盆栽试验和田间试验菜心地上部和地下部TCs含量均以OTC为主;盆栽试验和田间试验菜心地上部(以干重计)ω(OTC)分别高达29.25μg·kg^(-1)和45.03μg·kg^(-1),地下部含量(以干重计)ω(OTC)分别高达87.32μg·kg^(-1)和135.44μg·kg^(-1);且田间试验菜心地上部和地下部3种TCs含量均显著高于盆栽试验.土壤TCs的残留以OTC为主,盆栽试验和田间试验土壤ω(OTC)分别高达604.30μg·kg^(-1)和1013.68μg·kg^(-1);3种TCs在田间试验土壤残留含量显著高于盆栽试验.试验条件下,除田间试验菜心OTC含量对儿童的人体健康具有中风险外(HQ>0.1),其它处理菜心3种TCs含量对成年人和儿童的人体健康风险均较低(HQ≤0.1);盆栽试验和田间试验土壤3种TCs残留均具有中等或高生态风险(HQ>0.1或HQ>1).因此,畜禽粪肥还田引起的土壤TCs污染对蔬菜安全和土壤生态风险的影响不容忽视.

The effects of antibiotic contamination on vegetable safety and the ecological risks of soil after returning livestock and poultry manure to the land require sufficient future attention.Tetracycline antibiotics(TCs)are often detected at high concentrations in livestock manure and vegetable production soils.Recently,pot experiments and field investigation methods have often been used to understand the effects of TCs contamination on the vegetable safety and ecological risks of soil,whereas field experiments are employed less frequently.This study investigated the distribution characteristics of TCs in the soil-vegetable system following manure application using a combination of pot and field experiments.The human health risks of the edible parts of Chinese flowing cabbage were assessed using the health risk quotient method based on the acceptable daily intake(ADI-HQ),and the ecological risks of TCs-contaminated soils were evaluated using the risk quotient method associated with the species sensitivity distribution model(SSD-RQ).The results showed that oxytetracycline(OTC)was the major type of TCs in Chinese flowering cabbage based on both the pot and field experiments.The maximum contents(dry weight)of OTC in the aboveground parts of the Chinese flowering cabbage for the pot and field experiments were 29.25μg·kg^(-1)and 45.03μg·kg^(-1),respectively,whereas those of their underground parts were 87.32μg·kg^(-1)and 135.44μg·kg^(-1),respectively.Meanwhile,higher contents of TCs were detected in Chinese flowering cabbage collected from the field experiment than those from the pot experiment.OTC was also the major type of TCs in soil from both the pot and field experiments,with their contents up to 604.30μg·kg^(-1)and 1013.68μg·kg^(-1),respectively.Higher residual contents of three TCs were detected in soils collected from the field experiment than those from the pot experiment.Under the experimental conditions,with the except that OTC in Chinese flowering cabbage from the field experiment would pose medium health risks(HQ>0.1)to children,the contents of three TCs in other treated Chinese flowering cabbage would pose low health risks(HQ≤0.1)to adults and children.In the pot experiments,three TCs present in Chinese flowering cabbage would pose low health risks(HQ≤0.1)to adults and children.Additionally,the TCs in soils with manure application from the pot and field experiments may have posed both moderate or high levels of ecological risks(HQ>0.1 or HQ>1).Therefore,the effects of antibiotic contamination on vegetable safety and their potential ecological risks on soil following manure fertilization need to be given special attention.