Which activity can cause fixed contamination to become airborne?

• A. Typing on a keyboard
• B. Walking normally
• C. Showering
• D. Welding and grinding

Answer: (D)

Understanding how fixed contamination becomes airborne: fixed contamination sticks to surfaces and isn’t easily rubbed off. It becomes airborne when the material is disturbed enough to create dust or aerosol particles that can be breathed in. Welding and grinding involve strong mechanical action and heat that can dislodge surface contaminants and produce fine particles and fumes, turning a previously fixed contaminant into airborne material in the worker’s breathing zone. The other activities don’t provide enough disturbance to release contamination into the air—typing on a keyboard or walking normally simply doesn’t generate aerosols, and showering tends to wash away contamination rather than aerosolize it.