Environmental emissions of antibiotics and ARGs in China: Trends, regional variability, and the role of socioeconomic factors

The widespread use of antibiotics and the rise of antibiotic resistance genes (ARGs) pose significant environmental and public health threats. Accurately estimating their environmental emissions is essential for developing effective pollution control strategies and mitigating the risks associated with antimicrobial resistance (AMR). This study presents a comprehensive emission inventory for antibiotics and ARGs in China from 2001 to 2020, covering livestock farming, aquaculture, and human pharmaceutical use, addressing existing gaps in national-scale emission data. In 2020, total antibiotic emissions were estimated at 24,633 tonnes, with swine farming being the largest contributor (59 %). The total ARG emissions were estimated at 2.57 × 10²⁷ copies, with swine and poultry farming together accounting for more than 70 % of these emissions. Composition analysis identified tetracyclines, sulfonamides, and quinolones as the most prevalent antibiotics, which correspond to the dominant ARGs in emissions. From 2001–2020, a general decline in emissions was observed, especially after 2015, following the implementation of national regulatory measures. Spatial analysis revealed a shift in pollution hotspots from coastal to inland areas, with factors such as livestock density and wastewater treatment infrastructure influencing these regional disparities. Further analysis showed that GDP and population density were key socioeconomic drivers of emissions, with GDP growth generally contributing to emission reductions through improved governance and infrastructure, while population growth exerted positive pressure by intensifying antibiotic use and waste generation. This study provides valuable data for developing region-specific pollution control strategies and emphasizes the need for continued efforts to manage the persistence of ARGs in the environment.