Does Mold Cause Lung Cancer?

Medically Reviewed by Paul Boyce, MD on November 04, 2023
3 min read

Mold can cause health problems, especially allergies and asthma. But you probably don’t have to worry about it leading to lung cancer.

No research directly ties mold and lung cancer. In fact, it’s a pretty far stretch to find any connection at all.

The only possible link is this: Mold can cause pulmonary fibrosis (PF), which is scarring in your lungs. If you have PF for a long time, it can make you more likely to get lung cancer. But most of the time, people don’t know how they got PF, and mold isn’t a leading cause. So even this possibility isn’t strong.

If you’re concerned about mold affecting your health in other ways, it helps to know what it is and how to get rid of it safely.

Molds are a type of fungus. They thrive in warm, damp, humid places, indoors and out. They spread by making tiny spores, smaller than breadcrumbs, which float through the air to find new homes.

Mold is everywhere, and most of the time, you can’t see it. It can grow in your bathroom, basement, and the pile of leaves in your backyard. Basically, if it’s moist enough, it’s a landing spot for black, orange, white, green, brown, and maybe even fuzzy, mold.

Allergies are the most common health problem that mold causes. You may get symptoms like:

Mold can also trigger an asthma attack. Or chronic sinusitis, where your sinuses swell up and won’t settle down.

Those are the main things you can expect. But if you have a long-term lung condition or a weak immune system, it can lead to more serious issues, such as:


Some molds do make toxins, but scientists don’t actually call them “toxic” molds. That name came more from the news than science. Two of the more well-known types are Stachybotrys and Aspergillus.

Stachybotrys. Better known as black mold, this one gets a lot of press. But there’s no research that shows a definite link between its toxins and serious illness.

That doesn’t mean it’s not a concern, but it’s often blamed without real proof. Researchers are still trying to understand if and how it affects people.

Black mold isn’t rare, but it’s also not very common. And it needs a lot of moisture to grow. So even if you have black-colored mold in your bathroom, it’s not likely this one.

Aspergillus. Some types of this mold make aflatoxins, which can make you very sick, even causing liver cancer. Typically, that’s from eating it, not breathing it in.

It grows on food, like corn, peanuts, and even coffee beans. There’s never been an outbreak of sickness from aflatoxins in the U.S. That’s because the U.S. and many other countries test their foods for it. And food makers treat for it before it reaches you. At low levels, it’s just not an issue.

That’s up to you, but the CDC doesn’t recommend it. Mold is everywhere, and there aren’t guidelines for safe levels of it.

If you have mold, it’s best to get rid of it no matter what kind it is. It can make you sick and damage your home.

First, you need to fix the problem that’s leading to dampness. If you don’t, the mold will come back.

For areas bigger than 10 square feet, you may want to call in a pro.

For smaller areas, you’ll have to throw out anything that’s soft or can soak up water, like carpets, drywall, and ceiling tiles.

On hard surfaces, scrub with a stiff brush or cleaning pad along with a general-purpose detergent in hot water. Then rinse with water and let completely dry.