We all like to think the air we breathe in our own homes or in our office buildings is safe and clean. If you can’t smell it, it’s safe, right? Unfortunately, many indoor spaces have contaminants in the air that could damage your health. And you can’t see, smell, or taste them.
As many people began working at home during the COVID-19 pandemic, the issue of indoor air quality has become more important than ever. Indoor air is often more polluted than outdoor air, a shocking fact that’s tough to swallow. Whether you’re back in the office or still working from home, the air you breathe all day could be hurting you.
Knowledge is power. Know the top indoor air pollutants, where they come from, and how they could harm your health so that you can do something about it. These are 13 of the most common and damaging indoor pollutants you may encounter, even if you don’t work in what is considered a dangerous job:
Asbestos is not always listed as an indoor air pollutant despite the harm it can cause, including the rare cancer mesothelioma. Be especially aware of asbestos if you live or work in an older building.
- Sources: Asbestos is rarely used today, but in past decades you could find it in numerous building materials. These included insulation, roofing, siding, vinyl flooring, textured paint, fireproofing materials, and some types of adhesives and wallboard.
- Exposure risk: The risk of exposure to asbestos is much lower today than in the past, but it lingers in older buildings. If your home or office was built before he 1970s, it could have asbestos throughout. The risk of exposure is greatest when the old asbestos materials deteriorate or are disturbed by repairs or remodeling. This allows the fibers to come loose and pollute the air.
- Health Hazards: Asbestos causes or increases the risk for several health conditions. If you breathe in the fibers, they can lodge in tissues and cause damage that, over decades, leads to lung cancer, asbestosis, or mesothelioma. The latter is a rare and aggressive cancer that is nearly always fatal and almost always caused by asbestos exposure.
Lead is a toxic metal that contaminates many homes and buildings. Lead dust can permeate the air. There is no safe level of lead exposure.
- Sources: The most common source of lead in a home or building is old paint. You may find lead-based paint in homes built before 1978. Lead can also come indoors from outside. You can pick up lead on your shoes from contaminated soil.
- Exposure risk: If you keep old paint well maintained, it poses minimal risks to health. However, when paint begins to flake or chip, you may get lead dust on surfaces and in the air. The risk of bringing lead into the home from contaminated soil increases if you are near polluted sites like mines, lead smelters, or old agricultural fields.
- Health hazards: Lead is particularly dangerous as a pollutant because it accumulates in the body, causing harm long after exposure. Lead largely affects the nervous system. Children are most vulnerable to the hazards, which include impaired cognitive function, lower IQ, and behavioral issues. Acute exposure can cause constipation, vomiting, seizures, and even death. Long-term, chronic exposure causes brain and kidney damage, harm to the reproductive organs, high blood pressure, and anemia.
The culprit behind the adverse health effects of dust in the air is the microscopic dust mite.
- Sources: Dust mites occur naturally and can be found in most homes and buildings. Where dust exists, there are mites, tiny arthropods you can’t see with the naked eye. Dust mites don’t bite or sting, but they leave behind fecal matter and body fragments that can cause harm.
- Exposure risk: Mites are present in greater numbers in some homes than others. They thrive in humidity. The more humid your indoor air, the more likely you are to have problematic levels of dust mites. You’re also at greater risk of exposure if your home or office has a lot of dust. Dust accumulates in fabrics and carpets. The more hard surfaces you have, and the cleaner the space, the lower the risk.
- Health hazards: Dust mites don’t cause health problems for everyone, but they trigger allergic reactions in many. If you have a dust mite allergen, or if you have asthma, they can trigger reactions and worsen symptoms.
Pollen is a biological pollutant not restricted to the air outside. People with allergies struggle indoors, too, when pollen gets in.
- Sources: Pollen comes from flowering plants and is essential for reproduction. Plants release pollen into the air to reproduce. Many types of plants produce pollen that triggers reactions in people. The most common plants that contribute to pollen allergies are grasses, ragweed, sagebrush, pigweed, lamb’s quarters, birch, cedar, and oak.
- Exposure risk: Exposure to pollen is more likely outdoors and at certain times of year. However, pollen can come into the home or into office buildings, especially with open windows. Even when windows stay shut, pollen can get in because the particles are so small and because most buildings are not perfectly sealed. Pollen is also more likely to come into your home if you have pets that go outside. They can carry it back in on their fur.
- Health hazards: Pollen is a health hazard for anyone allergic to it. It can cause watery eyes, digestive upset, coughing, sneezing, and dizziness. A bigger risk exists for someone with allergic asthma caused by pollen. Indoor pollen can trigger an attack with coughing, wheezing, breathlessness, and difficulty breathing.
Smoke from cigarettes or wildfires can pollute indoor air and cause significant health issues to those exposed.
- Sources: Smoke can readily come indoors from outside. Wildfires, even many miles away, can produce a lot of smoke that seeps in, regardless of windows and doors being shut. Smoke from industrial areas can likewise get inside readily. Smoke may also come from indoors, including from cigarettes and wood-burning stoves.
- Exposure risk: Those at the greatest risk for exposure to smoke live with someone who smokes cigarettes indoors. Living in an area with regular wildfires also puts you at a greater risk of exposure, as does having a wood-burning stove in the home or in many nearby homes or buildings.
- Health hazards: According to the American Lung Association, there is no safe amount of secondhand cigarette smoke exposure. It causes more than 7,000 deaths per year from lung cancer and many more from heart disease. Woodsmoke contains pollution in the form of particles, carbon monoxide, nitrogen oxides, and volatile organic compounds, many of which are carcinogens or can aggravate respiratory conditions.
6. Carbon Monoxide
Carbon monoxide is colorless, odorless, and tasteless, but it can be harmful and even deadly, especially indoors.
- Sources: Inside, carbon monoxide comes from gas appliances, woodstoves, furnaces, and space heaters. Outdoor sources that can leak inside include vehicle exhaust, gas lawn equipment, and charcoal grills. Anything that burns can potentially produce carbon monoxide.
- Exposure risk: Carbon monoxide exposure is a risk in any indoor space, especially modern buildings well sealed from the outside. The risk increases if you have appliances or woodstoves and furnaces that malfunction or if you use gas-powered equipment indoors.
- Health hazards: Low levels of carbon monoxide can cause headaches, fatigue, dizziness, weakness, chest pains, nausea, and confusion. High levels can cause you to pass out or even die from asphyxiation because it blocks oxygen from reaching blood cells.
7. Cleaners and Solvents
Ordinary household cleaners, as well as solvents like paint thinner, can permeate indoor air and pose health risks.
- Sources: Many cleaners and solvents found around the home give off volatile organic compounds (VOCs), substances that readily evaporate from them. These include any kind of aerosol spray, chlorine bleach, detergents, carpet and upholstery cleaners, air fresheners, oven cleaners, and floor and furniture polish. VOCs also come from some paints, varnishes, glues, and art supplies, like paint thinner.
- Exposure risk: The more of these products in the home or office setting, the greater the risk of exposure. The risk can be contained by storing them properly and with proper ventilation when using cleaners and art supplies.
- Health hazards: VOCs irritate airways and eyes, and many are carcinogens. They may aggravate asthma and other respiratory conditions.
Large amounts of pesticides are mostly used outdoors, but many people use them indoors to target insects and rodents.
- Sources: The U.S. Environmental Protection Agency reports that 75% of households use pesticides indoors. Office buildings may also use them to control pests. Products used as indoor pesticides target rodents, termites, insects, fungi, and microbes.
- Exposure risk: Homes and office buildings can generally control exposure risk by avoiding chemical pesticides and using alternative methods to manage pests. If you use pesticides indoors, you are at risk for exposure and resulting health effect.
- Health hazards: The hazards associated with pesticides depend on the product and chemical. Most cause eye, nose, and throat irritation. Some can impact the central nervous system and kidneys and increase the risk of developing cancer.
9. Sulfur Dioxide
Sulfur dioxide is largely an outdoor air pollutant that can creep indoors.
- Sources: Sulfur dioxide comes from burning fossil fuels. It is an outdoor air pollutant that comes from vehicle exhaust, coal power plants, and industrial facilities. Contaminated outdoor air can get into the air inside homes and buildings. Indoor sources include kerosene and space heaters.
- Exposure risk: The risk of exposure to sulfur dioxide indoors is low if you do not use space or kerosene heaters and if your outdoor air is relatively clean. The risk increases for homes or buildings in industrial areas, near large roads, and near power plants.
- Health hazards: Short-term exposure to sulfur dioxide aggravates asthma, especially in children, and other respiratory conditions.
10. Nitrogen Dioxide
Nitrogen dioxide is a product of combustion that can form indoors and outdoors.
- Sources: Nitrogen dioxide results from the process of burning fossil fuels. Vehicle exhaust is the primary source of this pollutant outdoors, although it also comes from power plants and diesel engines. Indoors, nitrogen dioxide comes from any combustion appliance, including gas stoves and kerosene heaters.
- Exposure risk: Indoor nitrogen dioxide levels can be higher than those outdoors in some homes. The greatest risk for high levels occurs in homes or buildings with kerosene heaters, gas stoves, and gas space heaters that are not vented. Average levels in most homes are about half of outdoor levels. You may have higher levels if you live in an urban environment or near heavily trafficked roadways.
- Health hazards: Nitrogen dioxide causes irritation and inflammation in the airways, coughing, wheezing, worse asthma symptoms, cardiovascular harm, and low birth weight.
Pests like insects and mice are not just a nuisance; they can actually give off substances that pollute the air and cause health hazards.
- Sources: Pests that pollute the air indoors include dust mites, cockroaches, rodents. Feces, urine, dander, and body parts may contribute to dust and air where pests infest an indoor space.
- Exposure risk: The risk of exposure to pests and their leavings depends on the building and location. For example, cockroach infestations are more common in urban areas and in the southern region of the U.S. Keeping offices and homes clean can reduce the risk of having pests inside.
- Health hazards: Cockroach droppings, body parts, and even saliva trigger asthma attacks. Rodent urine, once dried, can become airborne and cause allergic reactions. Although not pests, dander and saliva from pets can contaminate the air and also cause allergies in some people.
12. Mold and Mildew
Mold and mildew are both terms used to describe fungi that grow indoors.
- Sources: Fungi indoors grows in moist areas, especially where there are leaks letting water in from outdoors, in leaky or poorly ventilated bathrooms, where carpet is damp, or where moisture builds up around appliances. Mold produces spores that enter the air.
- Exposure risk: The risks of contamination of indoor air by mold spores increases with moisture levels. If you live or work in a humid area, mold may be a problem. Another risk is having leaks or poor cleaning efforts.
- Health hazards: Some people are allergic to mold. Mold spores in the air cause these allergic reactions and may also trigger or worsen asthma attacks and other respiratory illnesses.
Radon is a colorless, odorless, and tasteless gas that is extremely harmful to health.
- Sources: Radon is an element that comes from naturally-existing uranium in soil and rocks. Uranium breaks down over time to produce radon gas, which can get into homes through basement floors, foundations, and cracks. It can also come in through water in pipes, but this is less common.
- Exposure risk: Any home could potentially have dangerous levels of radon. Testing is the only way to know for sure, but if you have cracks in slabs or basement floors or foundations, you may have a greater risk.
- Health hazards: According to the American Lung Association, radon is the second most common cause of lung cancer.
How to Know if Your Workplace Air is Contaminated
Many dangerous indoor pollutants are impossible to detect directly or by smell or sight. For some, you should test or monitor regularly, including radon and carbon monoxide. Others can be avoided or minimized by proactive steps, while some can be remediated.
For instance, you could have mold if you have visibly damp areas in your workspace or a musty smell. Fix the problem that causes moisture and clean up the mold to eliminate the risk. Consider asbestos a potential risk if you have an older home and see damaged insulation or old flooring. Remediators can test for and remove asbestos safely.
You may be able to tell you have smoke in the air by smell, but low levels may be hard to detect. Similarly, you cannot easily detect other combustion pollutants like nitrogen and sulfur dioxide. If you suspect you have these types of pollutants in the air, consider using a filtering device.
Filters also help if you have allergies to dust mites, pollen, or dander. When weather and allergies allow, and if you have clean outdoor air, open windows, and doors as much as possible. Ventilation is an easy way to prevent all kinds of pollutants from building up in the air.
What to Do if You Have Been Exposed
If you have only now realized you have been exposed to certain indoor air pollutants, consider the risks. For things like radon, smoke, or asbestos, the long-term consequences can be serious. It may be worth seeing your doctor if you have concerns or want to be screened for cancer.
Exposure to a pollutant that causes a serious illness, like mesothelioma from asbestos, for instance, can have long-lasting consequences. If you suffered exposure in your workplace, you may be able to take legal action to hold an employer or company responsible and to seek compensation. A safe workplace is the legal responsibility of employers and your right as an employee.
Consult with a lawyer specializing in pollution, personal injury, and workplace incidents to find out more about your options. Indoor air is often more important than outdoor air. You spend hours in your home or office breathing the air. Make sure it’s as clean and safe as possible.
Page Reviewed and Edited by
Dave Halpern, Mesothelioma Attorney
Dave Halpern is a Pennsylvania and New Jersey mesothelioma attorney with over 30 years of experience. He has investigated hundreds of cases and won numerous multimillion dollar settlements and verdicts for asbestos victims. Dave prides himself on working tirelessly to help his clients in their time of need.