Every time you inhale, you are exposing yourself to millions upon millions of microscopic airborne contaminants. Some of these include dust, pollen, dander, mold spores, viruses, and bacteria. Too much exposure to these contaminants can cause all sorts of health problems, from the flu to asthma. Fortunately, these contaminants are normally too widespread to cause serious issues. During the winter, however, these contaminants can become much more of a threat. Read on to find out why air purifiers are so much more important to have during the winter.