True or False: Operating a forced air HVAC system decreases indoor radon concentrations.

Operating a forced air HVAC system typically does not decrease indoor radon concentrations and may, in fact, facilitate the movement of radon gas into living spaces. This system can create conditions that draw radon from the ground into the home, particularly if there are any depressurized areas within the building.

Radon is a naturally occurring radioactive gas that seeps from the soil into buildings. When an HVAC system is in operation, especially if it is causing air to be circulated or if it draws make-up air from the basement or crawl space where radon levels may be higher, the concentration of radon in the indoor air can actually increase.

The other options present alternative scenarios, but they do not accurately reflect how typical forced air systems interact with radon. A filtration system, for instance, may help with airborne particles but does not specifically target radon. Similarly, associating radon concentration variations directly with seasons can be misleading because radon levels are more closely related to building conditions than temperature changes alone. Therefore, the statement is false as the operation of a forced air HVAC system can often lead to higher radon levels indoors.