Zhao Fang-Kai, Chen Li-Ding, Yang Lei, Fang Li, Sun Long, Li Shou-Juan
State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Huan Jing Ke Xue. 2017 Dec 8;38(12):5237-5246. doi: 10.13227/j.hjkx.201705243.
Antibiotics have been widely used for agriculture, aquaculture, and livestock, as well as for human disease treatment, in recent decades. However, antibiotics cannot be completely absorbed, and most of them are excreted through urine and feces. A substantial part of the antibiotics enter soils through fertilization and irrigation. Antibiotics persist in the soil environment and threaten human and ecological security. Identifying the composition, distribution, and factors affecting antibiotics in soils with different land use types can help in understanding the spatial distribution and migration processes of antibiotics. In this study, a typical peri-urban catchment located in the Yangtze River delta was selected as the study area, and 82 sampling sites were selected based on land use and topographical features. Soil samples were collected at depths of 0-40 cm at each sampling site. The types and quantity of antibiotics in each soil sample were identified and analyzed by using HPLC-MS/MS in the laboratory. The composition and concentration of antibiotics in different soil layers and the land use types were compared, and the factors affecting the spatial distribution of soil antibiotics were analyzed. Results from this study showed that the total concentration of antibiotic compounds () ranged from 0.05 μg·kg to 395.55 μg·kg in the study area, and a significant spatial distribution of antibiotics was found between different land use types. The in cropland ranged from 0.35 μg·kg to 395.55 μg·kg, and tetracyclines (TCs) were the dominant antibiotics (81.45%). The in forestland ranged from 0.07 μg·kg to 3.65 μg·kg, with values significantly lower than those in cropland (<0.05). The in orchard soil were significantly lower than in cropland (<0.05), and no significant differences in antibiotics were found between orchards and forestland (>0.05). The analysis of the composition and quantity of antibiotics in the soils showed that tetracyclines (TCs) and quinolones (QNs) were the dominant antibiotic types in orchards (TCs:67.63%, QNs:29.55%) and forestland (TCs:13.25%, QNs:70.04%). The indices, including distance to town, distance to road, elevation, and C/N value in soils, were selected to explore the influence of human activity on soil antibiotic concentration. Results of the correlation analysis showed that the concentration of soil antibiotics decreased with increasing values of the four indices. This indicated that the concentrations of soil antibiotics in peri-urban areas were dominantly affected by land use and its spatial distribution, and the concentrations increased with the intensity of human activities. Results of this study can provide scientific guidance for soil management and soil security.
近几十年来，抗生素已广泛应用于农业、水产养殖和畜牧业以及人类疾病治疗。然而，抗生素不能被完全吸收，大部分通过尿液和粪便排出体外。相当一部分抗生素通过施肥和灌溉进入土壤。抗生素在土壤环境中持续存在，威胁着人类和生态安全。识别不同土地利用类型土壤中抗生素的组成、分布及其影响因素，有助于了解抗生素的空间分布和迁移过程。本研究选取长江三角洲地区一个典型的城郊流域作为研究区域，根据土地利用和地形特征选择了82个采样点。在每个采样点采集0 - 40厘米深度的土壤样本。在实验室中使用高效液相色谱 - 串联质谱法（HPLC - MS/MS）对每个土壤样本中的抗生素种类和含量进行鉴定和分析。比较了不同土壤层和土地利用类型中抗生素的组成和浓度，并分析了影响土壤抗生素空间分布的因素。本研究结果表明，研究区域内抗生素化合物的总浓度范围为0.05 μg·kg至395.55 μg·kg，不同土地利用类型之间抗生素存在显著的空间分布差异。农田中的浓度范围为0.35 μg·kg至395.55 μg·kg，四环素类（TCs）是主要抗生素（81.45%）。林地中的浓度范围为0.07 μg·kg至3.65 μg·kg，其值显著低于农田（<0.05）。果园土壤中的浓度显著低于农田（<0.05），果园和林地之间的抗生素含量无显著差异（>0.05）。对土壤中抗生素的组成和含量分析表明，果园（TCs：67.63%，QNs：29.55%）和林地（TCs：13.25%，QNs：70.04%）中主要的抗生素类型为四环素类（TCs）和喹诺酮类（QNs）。选取到城镇的距离、到道路的距离、海拔以及土壤中的碳氮比等指标，探讨人类活动对土壤抗生素浓度的影响。相关性分析结果表明，随着这四个指标值的增加，土壤抗生素浓度降低。这表明城郊地区土壤抗生素浓度主要受土地利用及其空间分布的影响，且浓度随人类活动强度的增加而升高。本研究结果可为土壤管理和土壤安全提供科学指导。
