High humidity may promote the accumulation of growth of microbial pathogens, such as: NOT listed as an example?

• A. Bacteria
• B. Dust mites
• C. Mould
• D. Pollen

Answer: (D)

Moisture in the environment provides the water activity that many microbes need to grow. Bacteria and mould readily multiply when surfaces stay damp and nutrients are available, so they are classic examples of microbial growth promoted by high humidity. Dust mites aren’t microbes themselves—they’re microscopic animals that flourish in humid conditions and can accompany allergenic material—but they’re not microbial pathogens. Pollen, however, is plant material and does not multiply as a microorganism, so it doesn’t fit as an example of microbial growth driven by humidity.