Which of the following is a common workplace biohazard?

• A. Mold spores.
• B. Helium gas.
• C. Water vapor.
• D. Carbon dioxide.

Answer: (A)

Biological hazards in the workplace are organisms or their byproducts that can cause illness or adverse health effects. Mold spores fit this category because they are fungal spores that can become airborne and be inhaled. Exposure can trigger allergic reactions, asthma symptoms, and even infections in some people, especially in damp buildings or for workers with weakened immune systems. Because mold grows where there is moisture—water damage, leaks, high humidity—it's a common concern in many indoor settings, from offices to warehouses. Controlling it involves addressing moisture sources, performing proper remediation, and using appropriate protective equipment when mold is present.

Helium gas is an inert, non-biological agent. Water vapor is just moisture and, while humidity can promote mold growth, it itself isn’t a biohazard. Carbon dioxide can be hazardous at high concentrations due to asphyxiation risk, but it’s a chemical/physical hazard rather than a biological one.