Could your car be making you sick?

Day in and day out, you probably don’t even think of how much you may depend on or use your car. But, did you know that the inside of your car could be bad for your health?

With hundreds of strains of bacteria in its interior at any given time, your trusty ride could be exposing you to potential illnesses. Here’s a look at the various things happening on the inside of your car that may be putting your health at risk.

Your car is a petri dish on wheels. This is because it’s basically filled with touch points—surfaces like doorknobs, phone screens, food trays on planes, and kitchen counters, for example—that are frequently handled and, therefore, contain hazardous bacteria, including fecal matter. Touch points in your car include the steering wheel, door handles, gear shift, and buttons on the radio, just to name a few.

And if you snack or eat in your car—and who doesn’t?—all the rotting food particles (ie, crumbs) can become breeding grounds for all of these bacteria to flourish in.

CarRentals.com conducted a study and found that, on average, 700 strains of bacteria are moldering away in most cars. For example, the average steering wheel has about 629 colony-forming units (CFU) per square centimeter. This makes it four times dirtier than a public toilet seat. Touching the steering wheel, then biting your nails, wiping your nose, or eating while you are driving exposes your body to these bacteria, opening the door to illness.

What to do: Clean the interior of your car every few weeks. Use an antibacterial cleaner or cloths to wipe down all touch points, paying special attention to the dashboard and any control buttons. And make it a habit to keep a tub of sanitizing wipes in your car. Use them both before and after you eat.

Your A/C vents are like a hotel for mold spores. When your A/C vents get damp, mold may start to form. This mold, in turn, can be carried in the flow of air that blasts from the vents when you turn on your A/C or heat. And chances are, you have them aimed right at your face for maximum cooling or heating.

According to the CDC, consistent exposure to mold can cause eye and throat irritation, as well as coughing and wheezing. What’s worse—if you smell mold when you turn on your A/C, it may be a sign that your evaporator core is moldy, according to the folks at Kelley Blue Book.

What to do: To dry out the evaporator core and vents, run your A/C blower without vents for about 10 minutes every so often. If the moldy smell persists, have your mechanic remove and clean your A/C vents, and check your evaporator core for mold (and clean and treat it, if necessary).

Airborne contaminants are zooming in through your A/C vents. Did you know that not using the air recirculation function on your A/C allows outdoor contaminants into your car? Things like car fumes, cigarette smoke, and sewage odors can enter your car, and bypass your cabin air filter.

What to do: To correct this, make sure you push the A/C button that looks like a recycling sign to recirculate the air inside the car’s cabin. That way, no outside contaminants will come in, and the cool A/C and warm, heated air will stay inside.

Your cabin air filter is dirty. If you don’t replace your cabin air filter once every year, you may be unnecessarily exposing yourself to dust, dirt, pollen, and other contaminants that can enter your car through the HVAC system.

What to do: Replace your cabin air filter once a year. Decide on a specific date, and mark it on your calendar.

You are inhaling too many exhaust fumes while driving. When fuel is burned in cars and trucks, carbon monoxide is released. A little carbon monoxide is okay, but if you spend a lot of time driving, inhaling too much can lead to carbon monoxide poisoning. Symptoms include weakness, confusions, nausea or vomiting, a dull headache, dizziness, and difficulty breathing.

What to do: Never turn your engine on in an enclosed space, and keep your windows closed if you are stuck in traffic to cut down on how much you inhale. Another good rule of thumb is to have your mechanic check and maintain your car’s exhaust system regularly.

Driving long distances limits movement. Unfortunately, long road trips can contribute to your risk of developing deep vein thrombosis (DVT). According to the CDC, there is a direct association between DVT and traveling long distances due to the long stretches of no movement you are subjected to. Those who are over 40 years old, obese, have had recent surgery, or have a medical history of blood clots are especially at risk.

What to do: Flexing your feet and stretching your calves is a must. Stop every few hours and stretch for a few minutes. You can also wear compression socks, especially if you’re already at risk.

So, remember to clean out the inside of your car regularly to get rid of some of those bacterial strains that may be making a home there. It may be hard to remember, but it will help you stay healthy in the long run.