Protective Masks Reduced Gastrointestinal Risks of Antibiotic-Resistant E. coli for Hospital Wastewater Treatment Plant Workers: A Quantitative Microbial Risk Assessment

The study found that exposure to antibiotic-resistant bacteria (ARB) in hospital wastewater poses significant risks to workers at wastewater treatment plants (WWTPs). In Thailand, 88% of untreated samples were positive for ESBL E. coli, while 40% of treated samples tested positive. The study found that aerosols and droplets posed a higher infection risk than hand-to-mouth contact. Mask use, particularly surgical and FFP2 masks, significantly reduced risks, bringing treated wastewater exposure below the benchmark. However, highly virulent E. coli risks remained high across all mask types.