Final answer:
Wearing just a dust mask in a silo gas environment is unsafe because dust masks don't protect against gases. A chemical-specific respirator or SCBA may be necessary for adequate protection against the health risks posed by air pollution from indoor and outdoor contaminants.
Step-by-step explanation:
It is potentially unsafe for Elizabeth to rely solely on a dust mask in an environment containing potentially dangerous silo gases. These agricultural gases often include hazardous substances such as ammonia or hydrogen sulfide, which can have serious health consequences if inhaled. Dust masks are typically designed for filtering particles, not gases or vapors. For protection against silo gases, a more appropriate respirator with cartridges specifically designed for chemical hazards is necessary to provide adequate protection.
Furthermore, in environments where there's a risk of oxygen deficiency, a self-contained breathing apparatus (SCBA) may be required rather than a simple mask. In light of serious hazards from indoor and outdoor air pollution, personal protective equipment should be chosen based on the specific dangers present, such as the presence of smog, asbestos, carbon monoxide, or chemical pesticides that can cause illness or death.