Environment Preservation Center, Kanazawa University, Kakumamachi, Kanazawa, Ishikawa 920-1192, Japan.
Environment Preservation Center, Kanazawa University, Kakumamachi, Kanazawa, Ishikawa 920-1192, Japan.
Sci Total Environ. 2023 Dec 1;902:166211. doi: 10.1016/j.scitotenv.2023.166211. Epub 2023 Aug 9.
Swine excrement is discharged into surface waters mainly as effluent in Asian countries. As swine production consumes more antibiotics and less water than humans, a mismatch of the size of swine farms and that of the rivers receiving their effluent could create severe pollution by antibiotics. However, little is known about the occurrence of antibiotics in such rivers. We therefore monitored seven veterinary drugs, six human drugs (including a metabolite), three drugs for both use (including a metabolite), and major water qualities at 30 sites in Japanese watersheds where swine outnumber humans and where their excrement is largely treated on-site by aerobic biological wastewater processes. The compositions of veterinary drugs differed substantially among sites, unlike human drugs, indicating various patterns of use among swine farms. Median concentrations at the 30 sites were <1 ng/L for seven out of the ten drugs used in livestock, whereas maximum concentrations were >1000 ng/L for three and 100-1000 ng/L for four of them, giving median-maximum among the sites of >3 log for two and 2-3 log for six of them. The spatial distribution ranges of concentrations of veterinary drugs were wider than those of human drugs (mostly <1.5 log) and other analytes (mostly <1 log), despite the correlation between those of total veterinary drugs and nitrogen, attributable to fewer swine farms than households, the intensive animal husbandry, and the various drug-use patterns among the farms. The range of maximum concentrations of veterinary drugs in the watersheds was comparable to those reported in other Asian watersheds with less strict management of swine excrement, attributable to their slow decay in conventional wastewater treatment on swine farms. Thus, attention should be paid to hot-spot pollution of antibiotics on large Asian swine farms adjacent to streams with limited dilution capacity.
猪粪主要以污水的形式排入地表水中，在亚洲国家较为常见。与人类相比，养猪业消耗的抗生素较少，用水量也较少，但如果猪场的规模与接纳其污水的河流规模不匹配，可能会导致抗生素严重污染。然而，人们对这些河流中抗生素的存在情况知之甚少。因此，我们在日本的一些流域监测了 30 个地点的 7 种兽药、6 种人用药（包括一种代谢物）、3 种人兽共用药物（包括一种代谢物）以及主要水质，这些流域中猪的数量超过人类，其粪便主要通过需氧生物废水处理工艺在现场进行处理。与人类用药不同，兽药在不同地点的组成有很大差异，这表明猪场的使用方式各不相同。在这 30 个地点中，有 10 种用于畜牧业的药物中有 7 种的浓度中位数都<1ng/L，而最大浓度>1000ng/L 的有 3 种，100-1000ng/L 的有 4 种，这 10 种药物在 30 个地点的浓度中位数-最大值对数范围为>3，对数范围为 2-3 的有 6 种。尽管总兽药浓度与氮之间存在相关性，但兽药浓度的空间分布范围大于人用药（大多<1.5 对数）和其他分析物（大多<1 对数），这是由于猪场数量少于家庭，集约化畜牧业以及农场之间各种用药模式造成的。与其他亚洲流域相比，这些流域中兽药的最大浓度范围相当，尽管亚洲其他流域对猪粪的管理较为宽松，但由于猪场常规废水处理中兽药的缓慢衰减，仍应注意这些流域中抗生素的热点污染。因此，应注意毗邻稀释能力有限的溪流的大型亚洲猪场的抗生素热点污染问题。
