Asthma is one of the most serious public health issues in the United States, affecting more than 25 million Americans, including an estimated 7 million children and the numbers are growing worse each year. In this two-part post, I wanted to highlight some of the most common causes of asthma, many of which are directly related to indoor air quality.


According to a 2007 study conducted at Lawrence Berkeley National Laboratory and funded by the EPA, an estimated 21 percent of asthma diagnoses in the United States is linked to mold and dampness in homes. While there is no way to completely eliminate mold inside your home, moisture control is the best way to limit mold growth. For individuals with mold sensitivities, inhaling mold spores can trigger an asthma attack.

Secondhand Smoke

Secondhand smoke, whether from cigarettes, pipes or cigars, involves exposure to a complex mixture of over 7,000 compounds, over 70 of which are known to cause cancer in humans or animals.

Approximately 3 million children aged 6 and under were reported to be exposed to secondhand smoke on a regular basis in their home. Exposure to secondhand smoke can cause new cases of asthma in children, trigger asthma attacks or exacerbate existing asthma symptoms.


Dogs, cats and other household pets can trigger asthma for people allergic to animal dander. For individuals who are very sensitive, the most effective method to eliminate exposure to allergens from pets is to not allow animals in the home. Walls, floors, carpets, furniture, linens and towels trap allergens from pets and should be cleaned thoroughly.

For many people suffering with asthma, isolation measures have been reasonably effective. Keeping pets away from sleeping areas and areas of the house with upholstered furniture and rugs and carpets have helped many people manage their allergies and asthma and allowing their pets into their homes.

Stay tuned for my next post, where I will share some of the other most common causes of asthma.