Children are particularly at risk, especially when you consider that some five million children in the U.S. suffer from asthma. There are several causes of indoor air pollution. Often, indoor heating and ventilation systems transmit these substances, which are inhaled and make people ill. Animal dander and hair are a big pollution source. Many people have allergic reactions to dander and hair.
Cats are a particular problem because they lick themselves.
So, the hair also contains saliva, and both can trigger reactions. If this poses a problem, it might be best to keep your pets outdoors, if possible. At a minimum, keep them out of your bedroom and carpeted indoor areas. And indoor air pollution gives us even another reason to hate cockroaches. Cockroaches and roach waste can trigger allergic reactions.