What role do parasites play in the context of wastewater treatment?

In the context of wastewater treatment, parasites are indeed primarily recognized for their potential to cause diseases in humans. When wastewater is not adequately treated, it can contain various pathogens, including parasites, which can pose significant health risks if they enter drinking water supplies or come into contact with humans.

The presence of parasitic organisms in wastewater emphasizes the importance of effective treatment processes to eliminate or reduce these pathogens. This aspect highlights the critical need for facilities to monitor and control for parasites as part of their overall health and safety protocols.

While the other choices touch on valid functions in the ecosystem or wastewater treatment context, they do not directly address the specific concern of human health risks associated with parasitic organisms in untreated or partially treated sewage.