In environmental monitoring for BEE, how do active and passive sampling differ, and what is an example of each?

• A. Passive sampling uses pumps to draw air.
• B. Active sampling relies on diffusion; example passive diffusive badges.
• C. Both require pumps.
• D. Active sampling uses pumps to actively draw air; an example is active sorbent tubes.

Answer: (D)

Active sampling and passive sampling differ in how air is collected. Active sampling uses a pump to actively pull a known volume of air through a collection medium, so the amount captured can be tied to a specific air volume for accurate quantification. An example is an active sorbent tube, where air is drawn through a sorbent material to trap target compounds for later analysis. Passive sampling relies on diffusion—the contaminant molecules move into the sampler without power, accumulating over time to give a time-weighted average exposure. A typical example is a diffusive badge or passive diffusive sampler. The other statements mix up which method uses a pump or which relies on diffusion, so they don’t correctly describe how these methods work.