What potential health risk is associated with plants that use trickling filters and activated sludge?

The potential health risk associated with plants that use trickling filters and activated sludge primarily revolves around the inhalation of airborne microorganisms. These processes are biological in nature, relying on the action of microorganisms to treat wastewater. During these treatment processes, particularly in systems that handle large volumes of wastewater, there can be an aerosolization of pathogens and other microorganisms. Workers in close proximity to these operations may be exposed to these airborne pathogens, which can include bacteria, viruses, and fungi. This exposure poses a risk of respiratory infections or other health issues, especially to individuals who may have compromised immune systems or pre-existing health conditions.

While contact with hazardous chemicals, exposure to high temperatures, and exposure to heavy metals are all important considerations in wastewater treatment facilities, they are typically associated with other aspects of the treatment process or specific operational issues rather than a direct consequence of the biological treatment methods like trickling filters and activated sludge systems. This specificity to airborne microorganisms underscores the importance of occupational health and safety practices within wastewater treatment operations.