spray bottle spraying mold
1 / 14


It's a type of fungus that puts tiny particles called spores into the air. They can sometimes cause serious lung infections if you have mold allergies, a lung condition such as chronic obstructive pulmonary disease (COPD), or a weak immune system -- your body's defense against germs. If you're sensitive to mold, fix any leaks in your home and avoid compost piles and lawns with clumps of cut grass.

Swipe to advance
photo of radon distribution illustration
2 / 14


You can't smell, touch, or see this gas, but it's the No. 2 cause of lung cancer in the U.S. behind smoking. It's made when natural uranium in rock, soil, and water breaks down. It gets into buildings through cracks in floors and walls, and around plumbing and electrical wire. The radioactive particles in radon damage your lungs when you breathe them in or swallow them. A simple test kit can see if you have high levels in your home. Your house is tested for it when you buy it.

Swipe to advance
photo of dog on carpet
3 / 14


It can trap mold, cockroach droppings, dust mites, and toxic gases -- and all can hurt your lungs. They enter the air when you vacuum the carpet or walk on it. The chemicals used to make and install carpet could also cause problems. Consider putting in wood floors or some other kind of hard surface. Or use throw rugs you can clean outside the home. Vacuum your carpet three times a week, and steam clean it every year.

Swipe to advance
photo of man spraying pestisides
4 / 14


These chemicals keep bugs away from farm crops and your lawn. If you eat, touch, or breathe them, it might cause problems with your nerves, hormones, eyes, skin, and lungs, too. Farmworkers and others who use them are more likely to get lung problems like asthma and COPD. Masks, goggles, and special clothes can help protect anyone who works around pesticides.

Swipe to advance
photo of people watching fireworks
5 / 14


Their color is created by different bits of metal that explode a fine powder into the air. This can trigger or worsen asthma and other lung and heart issues if you breathe it. Play it safe during a fireworks show by staying far from any drifting smoke. You could also use a breathing mask that filters particles.

Swipe to advance
photo of airbag that has deployed
6 / 14


A white, odorless chemical called sodium azide helps push these bags forward to protect you in a car crash. This creates a fine powder that may trigger asthma and other breathing problems. High levels might cause your lungs to fill with fluid. It could also irritate and inflame the walls of your lungs. Talk to your doctor right away if you notice lung problems after an airbag opens.

Swipe to advance
photo of baker in kitchen making bread
7 / 14


People who work as bakers cough, wheeze, and struggle for breath more than others. It may be from breathing all that flour. It's common enough to have its own name: baker's asthma. Over time it could worsen lung conditions like asthma and damage your lungs. And it seems to affect not only the baker, but their family as well, probably because of the dust carried home on clothes, skin, and hair.

Swipe to advance
photo of gas burner on stove
8 / 14

Gas Appliances

Cooktops, ovens, and space heaters can be hidden causes of lung problems. As gas burns, it makes a chemical called nitrous oxide that can inflame your lungs, make you cough and wheeze, and trigger asthma. You also make it when you burn wood, oil, coal, or kerosene. Make sure to install, clean, and maintain appliances properly, and pay extra attention to how well they send waste gases out of the house.

Swipe to advance
photo of cockroach on toilet
9 / 14


Their poop and bits of their bodies turn to dust, which settles on your floors, bedding, and furniture. You breathe it in when it gets stirred up by activities like vacuuming. This can cause allergies and breathing problems. Preschool kids who come into contact with the stuff can develop asthma. It helps to keep your house as clean and dry as possible, especially fabrics and carpet. 

Swipe to advance
photo of pet parakeet on finget
10 / 14


When some people breathe in airborne particles from bird feathers and poop, they get inflamed lungs and may end up with scar tissue there. It's sometimes called pigeon breeder's disease or bird fancier's lung. You may hear your doctor refer to it as hypersensitivity pneumonitis. Talk to a doctor if you notice symptoms after being around birds.

Swipe to advance
photo of man feeding cow
11 / 14


Farmer's lung is another type of hypersensitivity pneumonitis. Your immune system reacts to a mold that grows on grain, hay, or straw and inflames your lungs. It's worse on dairy farms, among cattle workers, and in places where it's wet at harvest time. The best thing to do is get away from the mold that causes it. Eventually, you might become less sensitive. Some drugs can cut down your allergic reaction.

Swipe to advance
photo of humidifier in home
12 / 14


It looks harmless enough. All it does is put moisture into the air to help you breathe better. But it could hurt your breathing, too. That's because a fungus can grow in your humidifier and get blown into the air. The same problem might also happen in air conditioners and heating systems. Your lungs develop an allergy to the fungus and get inflamed. To avoid trouble, clean and service your heating and cooling system.

Swipe to advance
photo of woman in jacuzzi
13 / 14

Your Hot Tub

Bacteria that develop in indoor hot tubs can enter your lungs when you breathe in the vapor created by the hot water. Your lungs may get inflamed and you could get a fever, cough, and breathing trouble. Be sure to clean and maintain hot tubs, showers, and pools, and see your doctor about any breathing problems.

Swipe to advance
photo of candles in home
14 / 14


The most common type, made from petroleum-based paraffin, releases chemicals into the air that may raise your risk of allergic reactions, breathing problems like asthma, and even cancer. Occasional use is probably OK, but lighting up every day may not be a good idea over the long term. For safer options, try candles made from beeswax or soy, and make sure there is good airflow whenever you burn anything.

Swipe to advance

Up Next

Next Slideshow Title

Sources | Medically Reviewed on 10/26/2020 Reviewed by Sabrina Felson, MD on October 26, 2020


  1. Thinkstock Photos
  2. Thinkstock Photos
  3. Thinkstock Photos
  4. Thinkstock Photos
  5. Thinkstock Photos
  6. Thinkstock Photos
  7. Thinkstock Photos
  8. Thinkstock Photos
  9. Thinkstock Photos
  10. Thinkstock Photos
  11. Thinkstock Photos
  12. Thinkstock Photos
  13. Thinkstock Photos
  14. Thinkstock Photos


American Association for the Advancement of Science: "Smoke from fireworks is harmful to health."

American Chemical Society: "Romantic, candle-lit dinners: An unrecognized source of indoor air pollution."

American Lung Association: "Hypersensitivity Pneumonitis Symptoms, Causes and Risk Factors," "Healthy Air: Cockroaches," "Air Quality: Fireworks," "Healthy Air: Carpets."

Asthma and Allergy Foundation of America: "Breathe Easier: Improving Indoor Air Quality in Your Bedroom."

CDC: "Facts about Mold and Dampness."

Canadian Centre for Occupational Health and Safety: "Farmer's Lung."

Cureus: "Hot Tub Lung: A Diagnostic Challenge."

Environmental Science and Pollution Research: "Emission of air pollutants from burning candles with different composition in indoor environments."

International Journal of Environmental Research and Public Health: "Occupational Pesticide Exposures and Respiratory Health."

International Journal of Occupational Safety and Ergonomics: "Exposure to flour dust in the occupational environment."

Journal of Hazardous Materials: "Effect of fireworks events on urban background trace metal aerosol concentrations: is the cocktail worth the show?"

Mayo Clinic: "Pneumonitis."

National Safety Council: "Test Your Home to Determine Risk of Radon Gas Exposure."

Respiratory Medicine: "Morphologic diversity of chronic pigeon breeder's disease: Clinical features and survival."

South Carolina State University: "Frequent use of certain candles produces unwanted chemicals."

Environmental Protection Agency: "Nitrogen Dioxide's Impact on Indoor Air Quality."

Reviewed by Sabrina Felson, MD on October 26, 2020

This tool does not provide medical advice. See additional information.

THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for general informational purposes only and does not address individual circumstances. It is not a substitute for professional medical advice, diagnosis or treatment and should not be relied on to make decisions about your health. Never ignore professional medical advice in seeking treatment because of something you have read on the WebMD Site. If you think you may have a medical emergency, immediately call your doctor or dial 911.