Airborne antibiotics, antimicrobial resistance, and bacterial pathogens in a commercial composting facility:...

Area of Science:

• Environmental Science
• Microbiology
• Public Health

Background:

• Composting facilities can release antimicrobial resistance (AMR) elements into the air.
• Antibiotic resistance genes (ARGs) and human pathogenic bacteria (HPBs) are known airborne contaminants.
• The presence and role of airborne antibiotics in composting environments remain largely uncharacterized.

Purpose of the Study:

• To systematically quantify airborne antibiotics, ARGs, and HPBs in composting facilities.
• To compare airborne contaminant levels with those found in compost.
• To investigate factors influencing airborne contaminant concentrations and their co-occurrence.

Main Methods:

• Quantitative analysis of airborne and compost-associated antibiotics, ARGs, and HPBs.
• Environmental factor analysis (temperature, organic matter, heavy metals).
• Co-occurrence network analysis to assess contaminant relationships.

Main Results:

• Airborne antibiotic concentrations were significantly higher than in compost (4.17 ± 2.71 × 10² ng/g).
• Airborne ARGs concentrations also increased compared to compost (10² copies/g).
• Temperature, organic matter, and heavy metals influenced contaminant levels; greater complexity of antibiotic, ARG, and HPB co-occurrence was observed in air.

Conclusions:

• Composting facilities emit significant levels of airborne AMR elements, including antibiotics.
• Airborne antibiotics co-exist with ARGs and HPBs, posing potential health and environmental risks.
• Airborne antibiotics may play a role in the environmental evolution of AMR.