Residues and potential ecological risks of veterinary antibiotics in manures and composts associated with protected vegetable farming

Abstract

Veterinary antibiotics (VAs) are emerging contaminants and enter into soil principally by agricultural application of organic fertilizer. A total of 33 solid animal manures and 17 compost samples from protected vegetable farms in nine areas of China were analyzed for the antibiotic classes of tetracyclines, fluoroquinolones, sulfonamides, and macrolides (17 substances in total). Oxytetracycline was found as a dominant compound in the samples, and its highest concentration reached 416.8 mg kg −1 in a chicken manure sample from Shouguang, Shandong Province. Among the samples, animal manures (especially pig manure) contained higher VA residues than composts. However, fluoroquinolones exhibited higher persistence in the compost samples than other antibiotic classes. This is particularly the case in the rice husk compost, which contained the highest level of ofloxacin and ciprofloxacin (1334.5 and 1717.4 μg kg −1 on average, respectively). The veterinary antibiotic profile in the risk husk compost had a good relationship with that in the corresponding manures. The refined commercial compost had the lowest VA residues among the compost samples in general. This implied that composting process might be important to reduce the antibiotic residue. High residue of antibiotics in soil was assumed to be a hazard to ecosystem. This is especially noticeable under current application rates (150 t ha) in protected vegetable farming because over half of the samples exhibited a risk quotient (RQ) >1 for one or more antibiotics.

Levels, distributions and sources of veterinary antibiotics in the sediments of the Bohai Sea in China and surrounding estuaries

“…Method blanks showed no detectable amounts of the analytes. The calculations of the limit of detection (LOD), limit of quantification (LOQ), and method detection limit (MDL) are described by Zhang et al (2015a). The LOD and LOQ ranged from 0.09 to 3.16 μg L −1 and 0.49 to 10.5 μg L −1…”

Residues and risks of veterinary antibiotics in protected vegetable soils following application of different manures

“…In the case of chicken manure-amended soil, SCX as well as NFC and CFC are grouped into the first component, and another four SAs comprised the second component. SCX was identified to be a dominant SA in poultry manures in previous investigations by Zhang et al (2015). It was present in the highest concentrations among 17 antibiotics in chicken manure-amended soils from Suoshi, Nanjing (SS) ( Table 3).…”

“…Livestock manure and poultry manure have been found contamination with various antibiotics (Zhao et al, 2010;Zhou et al, 2013;Zhang et al, 2015). Hence, land application of manure has been recognized as a major source to the antibiotics contamination in soils (Ur Rehman et al, 2015;Wei et al, 2016).…”

“…It has been estimated that the total cropping area of protected vegetables in China had reached 4.67 million ha by the end of 2010, double the area in 2004 (Yu, 2011). Hence, antibiotics contamination in such high frequency vegetable rotation farming systems has increasingly been of concern in recent years (Li et al, 2013a;Fang et al, 2014;Hou et al, 2015;Ur Rehman et al, 2015;Zhang et al, 2015;Wei et al, 2016), and many of these studies have focused on soil contamination by the antibiotics. In this study, soil samples with varied manure applications and vegetable planting durations were collected to investigate the veterinary antibiotics residue in the soils of intensive vegetable land, and to evaluate the potential environmental risk based on the current residual level.…”

Changes in microbial community structures due to varying operational conditions in the anaerobic digestion of oxytetracycline-medicated cow manure

“…Also, their diversity is much narrower than bacteria so a disturbance in methanogenic community may affect other trophic levels. Especially, Methanosaeta and Methanosarcinales (acetoclastic methanogens) are extremely delicate and have the capacity to reflect in the performance of anaerobic digester and degradation of OTC and metabolites (Zhang et al 2014;Aydin et al 2016).…”