Indoor Air Pollutants
Common indoor pollutants that most affect health include:footnote 1
- Secondhand smoke, such as smoke from the burning end of a cigarette or smoke breathed out by someone who smokes.
- Radon. This is a type of gas that can enter homes through cracks and drains.
- Formaldehyde. It's released mainly by building materials.
- Acrolein. This comes from heating cooking oil to high temperatures. It also comes from cigarette smoke.
- Tiny particles, called respirable particulates, that can get into the lungs. Common sources are tobacco smoke and diesel exhaust.
Secondhand smoke
Secondhand smoke comes from the burning end of a cigarette, cigar, or pipe and the smoke that a smoker exhales. The smoke contains nicotine and many other harmful chemicals. Breathing secondhand smoke can cause or worsen health problems including cancer, asthma, coronary artery disease, and respiratory infections. It can make your eyes and nose burn and cause a sore throat.
Secondhand smoke is especially bad for babies and young children whose lungs are still developing. Children who breathe secondhand smoke are more likely to have ear infections, pneumonia, and bronchitis in the first few years of their lives. Secondhand smoke can make asthma symptoms worse in children.
If you are pregnant, it is important that you not smoke and that you avoid secondhand smoke. You are more likely to give birth to a baby who weighs less than expected (low birth weight) if you smoke. And your baby may have a greater risk for sudden infant death syndrome (SIDS). Babies whose mothers are exposed to secondhand smoke during pregnancy have a higher risk for health problems.
Secondhand aerosol from vapes does not contain as much nicotine and other harmful chemicals as secondhand tobacco smoke does. But there is a concern about possible health risks from secondhand aerosol exposure.
Radon
Radon is a colorless, odorless radioactive gas that can enter your home through cracks in concrete walls and floors and through floor drains. The most common source of radon is uranium that normally exists in the soil or rock on which homes are built. Problems show up when the concentration of radon builds up in a home or building. Both old or new homes can have problems with radon even if they don't have a basement.
Exposure to radon gas is the second leading cause of lung cancer. (Tobacco smoke is the leading cause.) The risk of radon-associated lung cancer is much higher for people who smoke than for those who don't smoke.footnote 2
You cannot smell or see radon. But it's easy to test for it with a do-it-yourself kit available in hardware stores or through the U.S. Environmental Protection Agency (EPA).
Woodstoves and gas ranges
Woodstoves that are not properly maintained and vented can give off tiny particles (particulates) and gases, including carbon monoxide, nitrogen, and hydrocarbons. Children in homes heated with woodstoves are at increased risk for respiratory problems. Gas ranges, particularly when they are not well-vented or when they are used as a source of heat, may produce nitrogen dioxide, which can cause respiratory problems.
Building materials
Exposure to building materials, products used for home improvement, and textiles can cause health problems. For example, particleboard, insulation, carpet adhesives, and other household products emit formaldehyde, which can cause nausea, respiratory problems, dry or inflamed skin, and eye irritation. Newly built homes and the confined spaces of mobile homes can be a particular problem. Using environmentally safe products—such as paint that contains a low level of or no volatile organic compounds (VOCs)—can reduce the chemical load on your body.
Sick building syndrome
Experts coined the term "sick building syndrome" to describe acute symptoms that occur only during time spent in a particular building and that cannot be explained by any specific illness or cause.
Symptoms include headache, dry cough, dry or itchy skin, dizziness, nausea, difficulty concentrating, fatigue, sensitivity to odors, and irritation of the eyes, nose, or throat. Typically the symptoms improve after you leave the building.
Poor ventilation that restricts fresh air flow inside can be a cause of sick building syndrome. Carpet, adhesives, upholstery, manufactured wood, pesticides, and cleaning fluids can give off volatile organic compounds (VOCs), including formaldehyde. High concentrations of VOCs can cause cancer. Unvented gas and kerosene space heaters, woodstoves, fireplaces, and gas stoves can produce carbon monoxide and nitrogen dioxide. These gases can harm your health.
Also, chemicals that get into a building from the outside can cause sick building syndrome. Pollutants from cars and trucks and exhaust from plumbing vents and building machinery can enter a building through vents.
Bacteria, molds, viruses, and other biological contaminants
Bacteria and molds can breed in stagnant water that builds up in humidifiers, drain pans, and ducts, or where water collects on carpet, ceiling tiles, and insulation. Humidifier fever is an illness caused by toxins from microorganisms that grow not only in large heating and cooling systems in buildings but also in home systems and humidifiers. Legionella pneumophila is an indoor bacterium that can cause Legionnaires' disease.
Some viruses can survive on household surfaces, such as counters or floors, or they can get spread through the air when an infected person sneezes or coughs.
Pet dander, pollen, dust mites, molds, and rat and mouse urine are allergens that can cause asthma attacks, allergic rhinitis, and other lung problems. Symptoms of illness caused by biological contaminants include sneezing, watery eyes, shortness of breath, lethargy, dizziness, and digestive problems.
Exposure early in life to indoor allergens such as molds may increase the risk of allergies or asthma.footnote 3 When modern building materials get wet, they provide an ideal place for the growth of molds. Allergies to molds can also make asthma attacks worse or cause other breathing problems.
Asbestos
Asbestos is an insulating material commonly used from the 1950s to 1970s for soundproofing and to cover floors, ceilings, water pipes, and heating ducts. When this material becomes crumbly or frayed, asbestos fibers can be released into the air. Breathing asbestos fibers may cause lung cancer, asbestosis (scarring of the lung tissue), or mesothelioma.
Learn more
- Asbestos and Lung Cancer
- Carbon Monoxide Poisoning
- Radon