(3) Estimates of Dietary Exposure to Antibiotics Among a Community Population in East China

Publication Number: 334

Background: A variety of antibiotics presenting in foods and drinking water may lead to an important and inadvertent human exposure. East China is an economically developed area with a massive use of antibiotics and a high rate of antibiotic resistance (ABR). However, the profile of dietary exposure to antibiotics in humans has not been well-explored.

Objectives: This study aimed to evaluate the total intake level of antibiotics in human via foods and drinking water based on a community population in East China.

Methods: This study recruited 600 local residents from 194 households in Deqing County of Zhejiang Province starting in June 2019. Each participant was asked to complete a food frequency questionnaire to report the daily consumption of animal-derived foods and drinking water. Tap water samples were collected from ten households and assessed for the presence of 21 antibiotics in five categories. Data on antibiotic residues in animal-derived foods were obtained from the notification of unqualified edible agricultural products after special supervision sampling inspection in Deqing County. The dietary exposure to antibiotics in humans were estimated by combining the data of antibiotic contamination in foods and drinking water, and the information of dietary consumption.

Results: Participants were exposed to 16 of the 21 antibiotics evaluated, with the daily exposure estimates ranging from 15.1 μg to 1128 μg. The exposure varied greatly across antibiotics. Compared with other antibiotics, enrofloxacin made the largest contribution, with a median daily exposure of 120.2 μg (IQR:8.4-698.8 μg), followed by sulfamethazine (median: 33 μg, IQR: 2.8-162.6 μg) and oxytetracycline (median: 28.5 μg, IQR: 2.2-146.6 μg). The estimated exposure to antibiotics from drinking water (median: 26.7 ng, IQR: 16.1-37.4 ng) were substantially lower than those in foods (median: 216.4 μg, IQR: 87.5-323 μg). The exposure levels also varied across sex and age. Males and participants younger than 35 years were more likely to be exposed to antibiotics via dietary routes than others.

Conclusions: The community population were extensively exposed to multiple antibiotics via dietary sources in East China. The long-term exposure to low-dose antibiotics in animal-derived foods was the primary dietary exposure mode.