As many as one in five adults become sick with the flu in the U.S. every year, and more than 200,000 are hospitalized due to flu-related complications. If you live an area with high levels of air pollution, you may run an even greater risk of getting sick with the flu. What’s more, if you get the flu your symptoms are likely to be more severe.

Here’s what you should know about the link between the air you breathe and the flu:

1. Breathing air pollution increases your chances of getting sick with the flu.

Multiple studies have confirmed that exposure to elevated levels of air pollution increases the likelihood that you will become sick with influenza. Some of the specific pollutants associated with an increase in influenza cases include PM10 particulates, diesel exhaust, nitric oxides, sulfur dioxide and ozone.

Researchers believe that airborne pollution particles provide “condensation nuclei” to which virus droplets attach. These particles – with virus particles attached – remain airborne longer, allowing the virus to travel much farther than the distance covered when you sneeze.

• PM10 and other pollutants:A group of scientists in Hong Kong investigated the relationship between pollution levels and hospital admissions for asthma, pneumonia and influenza. They found the rate of admissions for these conditions increased when levels of nitrogen oxide, ozone and particulate matter (PM10) increased. The increased risk was highest for those more than 65 years of age.
• Diesel exhaust:A group of scientists in the U.S. studied the effects of breathing diesel exhaust on the likelihood of getting sick after being exposed to the flu virus. After half of the group was exposed to diesel exhaust for two hours, subjects in the study were given a live flu vaccine and their responses were carefully measured. Viral RNA levels were significantly higher in those who breathed the diesel exhaust for two hours.

2. If you have the flu, air pollution may make your symptoms worse.

Allergists say polluted air makes symptoms of the flu feel worse for those who are already sick. Pollution particles rub against the bronchial tubes and create inflammation and irritation similar to (and adding to) flu symptoms. This is especially apparent in high-pollution areas where pollution levels often peak during flu season.

Human cells respond to both pollutants and viruses by releasing chemicals called cytokines. Cytokines are proteins that serve as messengers for communications between the body’s cells. The chemicals are released by the body’s immune system, and cause inflammation and the release of fluids.

Steps you can take this flu season

It’s important to remember that the flu is a contagious disease that can lead to hospitalization and even death. Everyone can help by taking three actions to protect yourself and others from influenza:

1. Take the time to get a flu vaccine.This is the most important step in protecting against flu viruses, and is recommended yearly.

2. Take everyday preventive action to stop the spread of germs.Along with hygienic steps, this also includes the use of a high-performance air purifier such as the IQAir HealthPro® Plus to remove airborne viruses.

3. Give your immune system a boost.Your immune system needs sufficient levels of zinc and other micronutrients to function effectively. Herbal supplements such as echinacea and probiotics may also help strengthen your body’s immune system.

The more you know about the flu, how it spreads, and how it can be treated, the better your chances to avoid becoming infected and spreading the flu to others. For more information on what to do if you get sick with the flu, visit the CDC website at http://www.cdc.gov/flu/whattodo.htm.