Common Indoor Air Pollutants and Their Health Effects

Common Indoor Air Pollutants and Their Health Effects

Indoor air quality significantly affects health, as common indoor pollutants from everyday sources can cause irritation, worsen asthma and allergies, and potentially lead to serious diseases like lung cancer or heart problems.

Pollutants can be found everywhere

Click to learn more about each one.

Asbestos

Dust Mites

Radon

Building and Paint Products

Formaldehyde

Residential Wood Burning

Rodents

Carbon monoxide

Lead

Carpets and Rugs

Mold

Secondhand Smoke

Particulate Matter

Volatile Organic Compounds (VOCs)

Cleaning Supplies and Household Chemicals

Cockroaches

Pet Dander

Asbestos

How Does It Impact My Health?

Where Does It Come From?

• Inhaling asbestos fibers can cause serious lung diseases that develop years after exposure, including lung cancer, mesothelioma (cancer of the lung lining), and asbestosis (lung scarring that makes breathing difficult).
• The risk increases with long-term exposure and smoking. Workers and their families face higher risks if safety measures are not followed.

A naturally occurring fibrous mineral once widely used in building materials for insulation and fire resistance. Common in older homes, schools, and commercial buildings built before the 1980s (e.g., floor tiles, ceiling panels, insulation, and roofing). Disturbing these materials during renovation or demolition can release microscopic asbestos fibers into the air.

Building and Paint Products

How Does It Impact My Health?

• These chemicals can cause eye, nose, and throat irritation, headaches, dizziness, and nausea. Long-term exposure is linked to respiratory diseases, asthma, and certain cancers. Renovation or removal of old materials can release asbestos fibers or lead dust, which are highly toxic, especially for children.
• Proper ventilation and safety precautions help reduce exposure.

Where Does It Come From?

Materials used in construction, renovation, and home furnishings, such as plywood, laminate flooring, furniture, paint, adhesives, and carpeting, can release formaldehyde, volatile organic compounds (VOCs), benzene, and other chemicals. Older materials may also contain asbestos or lead paint.

Carbon Monoxide

How Does It Impact My Health?

• CO prevents blood from carrying oxygen through the body, causing headaches, dizziness, nausea, weakness, and confusion. High levels can lead to loss of consciousness or death.
• Long-term exposure may cause permanent brain or heart damage. It is one of the most dangerous indoor air pollutants because it gives no warning signs (no smell or color).

Where Does It Come From?

An odorless, colorless, and tasteless gas produced when fuels like gasoline, wood, oil, charcoal, or natural gas are burned. Common sources include gas stoves, furnaces, fireplaces, space heaters, charcoal grills, and car exhaust. It can build up indoors when ventilation is poor.

Carpets and Rugs

How Does It Impact My Health?

Where Does It Come From?

• Can cause allergies, asthma attacks, coughing, sneezing, and eye or throat irritation. VOCs from new carpets can also cause headaches and dizziness.

• Damp carpets may grow mold, worsening respiratory symptoms, especially in children and people with lung disease.

Carpets and rugs can collect dust, dirt, pet dander, mold spores, and chemicals from household products. New carpets may release VOCs from glues, dyes, and synthetic fibers. Poor ventilation or moisture can make these pollutants build up indoors.

Cleaning Supplies andHousehold Chemicals

How Does It Impact My Health?

• Can cause eye, nose, and throat irritation, headaches, and breathing problems.

• Long-term or repeated exposure may lead to asthma, lung damage, or chemical burns. Children, older adults, and people with asthma are especially sensitive.
• Always use good ventilation and avoid mixing chemicals.

Where Does It Come From?

Many cleaning products, air fresheners, disinfectants, and aerosol sprays release VOCs such as ammonia, chlorine, and formaldehyde. Mixing products like bleach and ammonia can create dangerous gases. Even “scented” or “fresh” products may emit chemicals that pollute indoor air.

Cockroaches

How Does It Impact My Health?

Where Does It Come From?

• Can cause allergies, asthma attacks, coughing, sneezing, and eye or throat irritation. VOCs from new carpets can also cause headaches and dizziness.

• Damp carpets may grow mold, worsening respiratory symptoms, especially in children and people with lung disease.

Common indoor pests that thrive in warm, humid areas with food and water, such as kitchens, bathrooms, and basements. Their body parts, saliva, and droppings can break down into tiny particles that settle in dust, bedding, and fabrics.

Dust Mites

How Does It Impact My Health?

• Their waste and body parts can trigger allergic reactions and asthma attacks, causing sneezing, runny nose, watery eyes, coughing, and breathing difficulties.
• Reducing humidity, washing bedding in hot water, and using allergen-proof covers can help limit exposure.

Where Does It Come From?

Tiny microscopic insects that live in bedding, mattresses, carpets, and upholstered furniture, feeding on flakes of human skin. They thrive in warm, humid environments and are present in most homes.

Formaldehyde

How Does It Impact My Health?

Where Does It Come From?

• Can cause eye, nose, and throat irritation, headaches, and breathing problems. Long-term exposure is linked to asthma, allergic reactions, and cancer of the throat and nose area.
• Higher temperatures and humidity make formaldehyde release faster indoors.

A colorless, flammable gas with a strong odor, classified as a VOC. It is used in making wood products, glues, paints, fabrics, insulation, and cleaning products. Smoking indoors, burning wood, or using products with adhesives can increase levels.

Lead

How Does It Impact My Health?

• Lead exposure, especially in children and pregnant women, can cause learning problems, developmental delays, and nervous system damage.

• In adults, it can lead to high blood pressure, kidney damage, and fertility problems.
• There is no safe level of lead exposure. Keeping homes clean and using certified professionals for repairs can prevent contamination.

Where Does It Come From?

A toxic metal once widely used in house paint, pipes, plumbing, batteries, and gasoline. Homes built before 1978 are most likely to contain lead-based paint or pipes that can release lead into dust, soil, or drinking water. Renovation or chipping paint can spread lead dust indoors.

Mold

How Does It Impact My Health?

Where Does It Come From?

• Mold exposure can cause allergic reactions, coughing, wheezing, nasal congestion, and sore throat. It can worsen asthma and other respiratory issues even in people without allergies.
• Keeping indoor spaces dry and well-ventilated helps prevent growth.

A natural fungus that grows in damp or humid indoor areas such as bathrooms, kitchens, basements, carpets, and walls. Mold develops when there is excess moisture from leaks, poor ventilation, or condensation. Common signs include musty odors, water stains, or visible growth.

Particulate Matter

How Does It Impact My Health?

• Their waste and body parts can trigger allergic reactions and asthma attacks, causing sneezing, runny nose, watery eyes, coughing, and breathing difficulties. Reducing humidity, washing bedding in hot water, and using allergen-proof covers can help limit exposure.

Where Does It Come From?

Tiny particles of dust, soot, smoke, or liquid droplets that float in the air. Larger particles are called PM10, and smaller, more harmful ones are PM2.5. Common sources include cooking, smoking, candles, fireplaces, gas stoves, cleaning sprays, outdoor vehicle exhaust, and wildfire smoke.

Pet Dander

How Does It Impact My Health?

Where Does It Come From?

• Can cause allergic reactions such as sneezing, runny nose, itchy or watery eyes, and skin rashes. Pet dander can also trigger asthma attacks or worsen breathing problems, especially in people who are sensitive or already have allergies.

Tiny flakes of skin, saliva, urine, or feces proteins shed by animals with fur or feathers (cats, dogs, birds, rabbits, etc.). These particles easily become airborne and stick to furniture, bedding, and clothing, remaining in the air for long periods.

Radon

How Does It Impact My Health?

• Long-term radon exposure is a serious health risk because radioactive particles from radon decay can damage lung tissue when inhaled.
• Radon is the second leading cause of lung cancer in the U.S. after smoking.

• It does not cause immediate symptoms, so people don’t know they are exposed.

Where Does It Come From?

A naturally occurring, radioactive gas that is colorless, odorless and tasteless. It forms when uranium in soil or rock breaks down into radium and then radon gas. Radon can seep into buildings through cracks in foundations, walls, floors, and other openings. It can also (less commonly) enter via water or building materials.

Residential Wood Burning

How Does It Impact My Health?

Where Does It Come From?

• These pollutants can cause coughing, wheezing, asthma attacks, and aggravate lung disease.
• They may also contribute to heart attacks, lung cancer, and premature death.

• Vulnerable groups (children, older adults, people with lung or heart disease) are especially at risk.

Burning wood indoors or from neighboring homes (fireplaces, wood stoves, outdoor wood burning). Smoke contains particulates, carbon monoxide (CO), nitrogen oxides (NOₓ), VOCs (e.g. benzene, formaldehyde), and other toxic gases.

Rodents

How Does It Impact My Health?

• Rodent waste can spread diseases such as hantavirus, leptospirosis, and salmonella, and may trigger asthma or allergic reactions.
• Symptoms can include fever, fatigue, shortness of breath, and respiratory irritation.
• Sealing entry points, keeping food stored properly, and cleaning safely (with gloves and masks) can reduce exposure.

Where Does It Come From?

Mice and rats often enter homes and buildings looking for food, warmth, and shelter. They leave behind droppings, urine, saliva, and nesting materials, which can contaminate food, air, and surfaces. When these dry, tiny particles can become airborne and inhaled.

Secondhand Smoke

How Does It Impact My Health?

• Causes eye, nose, and throat irritation, headaches, and breathing problems.
• Long-term exposure increases the risk of lung cancer, heart disease, stroke, and asthma attacks, especially in children and nonsmokers.
• It can also cause sudden infant death syndrome (SIDS) and ear infections in children. Keeping indoor spaces completely smoke-free is the best protection

Where Does It Come From?

A mixture of smoke from burning tobacco products (cigarettes, cigars, pipes) and the smoke exhaled by smokers. It can linger indoors for hours, especially in homes or cars with poor ventilation. There is no safe level of exposure to secondhand smoke.

Volatile Organic Compounds

How Does It Impact My Health?

• Short-term exposure can cause eye, nose, and throat irritation, headaches, nausea, and dizziness.
• Long-term exposure has been linked to liver, kidney, and nervous system damage, and certain cancers.
• Good ventilation, using low-VOC or fragrance-free products, and safely storing chemicals can help reduce indoor VOCs.

Where Does It Come From?

A large group of chemicals that easily become gases at room temperature. They are released from paints, varnishes, cleaning supplies, air fresheners, building materials, glues, cosmetics, and fuel-burning appliances. VOC levels are often much higher indoors than outdoors.