Biological hazards in collection system operations include which of the following?

• A. Noxious or toxic gases or vapors
• B. Oxygen deficiency
• C. Physical injuries
• D. Hepatitis A

Answer: (D)

Biological hazards come from living organisms or their disease-causing components. In wastewater collection work, pathogens can be present in sewage, making exposure a real concern. Hepatitis A is a virus that can be transmitted via contaminated sewage or materials and cause illness, so it fits squarely as a biological hazard.

The other options describe non-biological hazards: noxious or toxic gases or vapors are chemical hazards; oxygen deficiency is an atmospheric/physical hazard related to the environment; physical injuries cover general safety risks but not biological agents.

So Hepatitis A is the best choice because it specifically represents a disease-causing microorganism that workers can encounter in collection systems, whereas the others are not biological hazards. Protective measures include standard precautions, appropriate PPE, hygiene, and vaccination where advised.