What humidity level is recommended for homes of asthmatic children, and why are humidifiers discouraged?

• A. 60-70% humidity; humidifiers help with moisture.
• B. 30-50% humidity; humidifiers are not recommended because they can harbor mold.
• C. 10-20% humidity; dryness reduces triggers.
• D. 70-90% humidity; high humidity clears airways.

Answer: (B)

Keeping indoor humidity in a moderate range helps limit common asthma triggers like mold and dust mites. A target around 30-50% relative humidity reduces the conditions that support these irritants without making the air feel too damp or too dry. Humidifiers are discouraged because they add moisture that can feed mold, bacteria, and dust mites if not cleaned thoroughly or used with proper water quality. Excess moisture can spread mold spores and allergens, potentially worsening asthma symptoms. If the air is too humid, use a dehumidifier or air conditioning to bring it down and monitor levels with a hygrometer; extreme dryness can also irritate airways, so avoid pushing humidity too far in the other direction.