In a test on 1000 8-11 year old school children in Shanghai, Jiangsu and Zhejiang, over 58 % showed antibiotic metabolites in urine samples. In some cases, metabolites of antibiotics restricted to animal use such as chlorotetracycline, enrofloxacin and tylosin were found. In most cases, metabolites of more than one antibiotic were found, and in some cases concentrations exceeded 1000 ng/ml urine.
China Bio news release, April 17, 2015