Here’s how a dirty air conditioner affects your breathing

Have you ever changed the filter in your air conditioner or, like, cleaned it? I haven’t (gulp), and apparently that is bad news bears for my health—especially as temperatures rise and I’m forced to keep my (dirty?) unit running 24/7 in order to, you know, survive. But really, what’s the worst that can happen if I don’t maintain my machine, which seems to be running just fine despite such gross neglect?

When I looked into this myself, all I found were terrifying articles about something called “air-conditioner lung.” It’s a very rare and serious immune reaction to small airborne particles, but according to Raj Dasgupta, MD, a pulmonologist at USC’s Keck School of Medicine, it’s not the only problem caused by a dirty air conditioner. When you fail to maintain your air conditioner, it collects high concentrations of dust, pollen, and mold. At best, this could exacerbate allergies and asthma. At worst, it can cause infections.

Dr. Dasgupta places these infections into three categories: “Number one is viruses, number two is bacteria, and number three is fungi or mold,” he explains. There’s a particular bacteria (legionella) that can cause a type of pneumonia known as Legionnaire’s disease which can easily land you in the ICU, he says. Certain populations, including those with existing respiratory disease or who have weakened immune systems, need to be especially wary of an unclean machine.

In some cases, people might experience air conditioner-related health issues even if the unit is clean as a whistle. “You know what one of the triggers of asthma is? Cold air,” he explains. “The cold air itself can cause asthma, not to mention all the dust and pollen.” Other side effects of using an air conditioner (regardless of the machine’s cleanliness) include dry eyes, sore throat and, if it’s really cold, worsening arthritis in elderly individuals.

That said, Dr. Dasgupta stresses that the health benefits of using an air conditioner far outweigh the risks. “Air conditioning in a heat wave is a blessing, with three exclamation points,” he says. “It decreases the chances of heat exhaustion and dehydration.” This is an especially critical function for vulnerable populations such as the elderly and the very young. As a pulmonologist who specializes in sleep, Dr. Dasgupta notes that cool environments are critical for catching ZZZs.

The answer, then, isn’t to ditch your air conditioner, but rather to ensure it’s well maintained. Learn how clean your conditioner yourself, or ask your landlord or a handyman to help.

Oh, and humidifiers pose all the same risks as a dirty air conditioners, so it’s important to make sure they’re regularly cleaned as well; however, Dr. Dasgupta says the benefits once again outweigh the risks. “When you get dry nose it sets you up for infection,” he explains. If you don’t have a humidifier or don’t want to deal with the hassle of regular cleaning, he suggests a hack: add plants to your sleeping space. “What plants do is they take up the carbon dioxide that we breathe out at night and give out oxygen, which gives humidity to the room,” he explains.

If only a little greenery could sub in for the expensive, not-so-eco-friendly, and apparently potentially infectious machines we rely on to survive the summer.

Want more healthy home gadgets? Check out this W+G guide to the best purifiers and humidifiers. Plus, here’s a little insight into the types of analogue help, aka plants, you should enlist for your space, stat.