A study published in Scientific Reports has quantified the inhalation exposure of wastewater treatment plant workers to airborne bacterial and fungal bioaerosols, and run a non-carcinogenic risk assessment of the levels measured on-site. Workers in the screening, aeration, and sludge-handling zones were exposed to elevated concentrations of culturable fungi alongside bacterial species, with seasonal variation in the mix.
The authors conclude that occupational bioaerosol exposure at the plants studied warrants improved ventilation, personal protective equipment, and monitoring programs, particularly for workers stationed near aerosol-generating processes. The risk-assessment framework used in the paper draws on EPA and WHO inhalation reference values.
Bioaerosol research in water-damaged indoor environments has historically focused on residential and office buildings; the new data extend the occupational exposure picture into a class of facilities where workers may inhale large volumes of fungal spores and fragments every shift.