Modeling human-use antibiotics pollution in Chinese Rivers: A multi-scale analysis of drivers, pathways, and hotspots

Area of Science:

• Environmental Science
• Public Health
• Ecotoxicology

Background:

• Antibiotic emissions from human use in China endanger aquatic ecosystems and promote antimicrobial resistance.
• Current assessments lack facility-level detail for effective policy and mitigation.

Purpose of the Study:

• To improve understanding of human-use antibiotic emissions to water systems in China, including spatial distribution, pathways, risks, and mitigation.
• To develop a model for quantifying antibiotic emissions from wastewater treatment plants (WWTPs).

Main Methods:

• Developed the SEAAL-China model to quantify emissions of 19 major antibiotics from sewered and unsewered populations.
• Analyzed removal efficiencies across over 10,000 WWTPs with varying treatment technologies.
• Modeled total antibiotic emissions to water systems in China for 2020.

Main Results:

• Significant variation in WWTP removal efficiencies (30-90%), with 57% employing moderately effective technologies (<60% removal).
• Total emissions reached 3741 tons in 2020, with the unsewered population (41%) contributing over half.
• Emission hotspots identified in Guangdong, Shandong, and Henan, driven by GDP and healthcare infrastructure imbalances.
• Fluoroquinolones identified as the dominant class in co-occurring emission and risk hotspots (630 counties).

Conclusions:

• Expanding basic sanitation in rural/peri-urban areas is crucial to address the sanitation deficit and reduce emissions.
• Prioritizing WWTP technology upgrades in hotspot areas is essential to mitigate pollution.
• Findings support region-specific and compound-specific management strategies for antibiotic pollution.