With winter's low temperatures, indoor environments can become very dry due to heating. Humidifiers are often used to prevent or reduce dry skin, lips and throat but they can create issues if they are not maintained properly. Those with sensitive respiratory systems such as the elderly, young or those with conditions such as COPD can be negatively impacted through the use of a humidifier from the unintentional introduction of airborne pollutants.
The most common type of humidifier emits a "cool mist" which is created either through ultrasonic sound vibrations or a rotating disk. Studies, such as those by the EPA have shown that micro-organisms and minerals can be dispersed into the air with this type of humidifier. Micro-organisms can grow in standing water and when they are emitted into the air via the humidifier it can create issues for those with a sensitive respiratory system. So, here is what you do:
The "cool mist" humidifiers can be very beneficial to improving the indoor air quality. The key is in investing the time to properly maintain these systems so they do not create potentially dangerous situations.