Air pollution has been linked to the premature births of up to 6 million babies worldwide every year, with indoor air pollution contributing to approximately two-thirds of the total exposure. According to the United States Environmental Protection Agency (EPA), cooking, cleaning, and even our pets are among the common pollutants that can negatively impact the quality of our indoor air. High levels of prolonged exposure to pollution can cause adverse health effects like respiratory infections, heart disease, certain cancers, and even death. Babies and children, older individuals, and people with underlying health conditions are most at risk from the effects of pollution. Here we explore the common sources of our indoor air pollution, outline how that can impact our family’s health, and, finally, list ways that we can all clean up our indoor air.

Why Your Indoor Air Quality Is Important

The word “pollution” is more commonly associated with carbon monoxide emissions from vehicles than sources inside our homes. However, the air we breathe indoors can be up to five times more polluted than that of outdoor air, say the EPA. “The potential for and types of health impacts from indoor air pollution depend on many factors, including the type and amount of pollutants, individual health status and sensitivities of occupants, various building and room factors, and indoor ventilation,” a spokesperson for the EPA tells us.  “In some cases, high levels, long, or repeated periods of exposure to certain indoor pollutants have been associated with respiratory diseases, heart disease, cancer, and even death. Some indoor air pollutants can also exacerbate chronic health conditions such as asthma,” says the EPA spokesperson.   And with studies now linking higher COVID-19 mortality rates to areas with high pollution, the quality of the air we breathe is a cause for concern.

How Indoor Pollution Affects Children

Babies and children are among the most susceptible to the negative effects of poor indoor air quality as their lungs are still developing. As Elizabeth Matsui, MD, MHS, a professor of population health and pediatrics and the director of clinical and translational research at Dell Medical School in Texas explains: pollution, allergens, and infectious microbes can all be found in indoor air and they can all affect the wellbeing of our children. “Indoor air can have a large impact on our children’s health, causing chronic nasal congestion, coughing, and difficulty sleeping because of respiratory symptoms—to name the most common symptoms,” says Dr. Matsui. Indoor allergens—such as dust or pet hair—are major contributors to asthma symptoms and attacks among children who are allergic to them, says Dr. Matsui. In terms of the long-term health risks associated with poor air quality, one study has linked the exposure of high levels of pollution in childhood to poorer mental health later in life. The study, conducted at the Institute of Psychiatry, Psychology, and Neuroscience at King’s College London, found that exposure to certain pollutants increased the probability of a child suffering from mental disorders like depression or anxiety by the time they turned 18.

How Indoor Pollution Affects Babies And Pregnant Individuals

Pollution poses a health risk to babies too, and often before they are even born. A recent global study associated premature births with air pollution among 6 million babies during the year 2019. In addition to this, the study found a correlation between pollution and low birth weight, which is classified as a birth weight of fewer than 2500 grams (5 lbs 5 oz), among 3 million babies. “The indoor levels [of pollution] are substantially higher compared to the outdoor levels,” says Rakesh Ghosh, PhD, an epidemiologist at the University of California, San Francisco, and lead researcher on the study. “If we can, [we hope to] extend the message as part of basic to prenatal care that exposure to pollution is harmful.” This isn’t the first time that scientists have made the link between pollution impacting the health of babies in utero. A study published in 2020 discovered that the tiny particles found in polluted air were able to reach the placenta, and possibly pass through to the fetus.

Common Indoor Air Pollutants

You often cannot see the pollutants in your home, and how many there are and what they are vary depending on your own personal environment and circumstances. Common sources of indoor can include the following.

Particulate Matter

According to the World Health Organization (WHO), particulate matter (PM) is the term for the tiny particles found in pollutants like dust, smoke fumes, and gases. Particles less than 2.5 micrometers in diameter (PM2.5) or smaller are more harmful than larger particles as they are easily inhaled and absorbed in the body. These particles are roughly 30 times smaller than a strand of hair. Common indoor sources of these fine particles include tobacco products and indoor fuel-burning appliances like wood-burning stoves, open coal fireplaces, and even candles.

Outdoor Air Pollutants

According to the American Lung Association, 40% of people in the United States are living in places with particulate pollution, and this polluted air can easily infiltrate your home. Additionally, radon—a naturally occurring radioactive gas that is the second leading cause of lung cancer behind smoking—can enter your home through cracks in your building’s walls and foundations. The good news is that radon can be tested for and a mitigation system can be put in place.

Mold And Mold Spores

Mold thrives in warm, moist conditions like bathrooms or kitchens. The presence of mold and mold spores can trigger asthma symptoms in those that have the condition. The Centers for Disease Control and Prevention recommends keeping humidity levels at no higher than 50% to help deter mold from growing.

Pests, Such As Insects And Rodents

Pests, or rather their excrement (yuck), are another common source of indoor pollution. The allergens that cockroaches, rodents, and other insects produce settle on dust and other fabrics. When disturbed, they become airborne and are easily inhaled. Not only are pests another potential trigger for asthma sufferers, but some studies also suggest that exposure to cockroach excrement could actually cause pre-school-aged children to develop asthma.

Carbon Monoxide

Carbon monoxide (CO) is a poisonous gas with no taste or smell. Around 50,000 people seek medical attention every year due to accidental carbon monoxide poisoning. Faulty gas stoves, furnaces or boilers, back-burning from an open fireplace, and exhaust emissions from a vehicle idling in a garage are all potential sources of carbon monoxide. If carbon monoxide is present in your home, the first symptom you might experience is a headache or other flu-like symptoms. High levels of carbon monoxide can be fatal.

Volatile Organic Compounds (VOCs)

Volatile organic compounds (VOCs) are often human-made chemicals commonly found in a huge number of household products, including cleaning supplies, paints, pesticides, building materials and furnishings. VOCs are emitted as a gas, and common symptoms of VOC exposure are eyes, nose and throat irritation, headaches and dizziness.

How To Improve The Air Quality In Your Home

Understandably, the idea that pollution can exist inside your home and potentially be harming your family’s health can feel alarming. However, there are plenty of practical changes you can make to clean up the quality of your indoor air. “The best way to improve indoor air quality is to reduce pollutants and sources, ventilate with clean outdoor air, and supplement with air cleaners,” says the EPA spokesperson. Here’s how to do this.

Ban Smoking Indoors

When it comes to smoking, the advice is clear: both firsthand and secondhand smoke (known as environmental tobacco smoke or ETS) is harmful to your and your family’s health. ETS releases approximately 7,000 chemicals into the air, 250 of which have been identified as poisonous and a further 70 are known carcinogens. “The one change that would have an enormous impact on the health of our children is to not smoke in the home and do not allow smoking in the home,” says Dr. Matsui. Babies and children are more susceptible to the effects of secondhand smoke as their lungs are still developing. So, if you haven’t already, now is the time to ban smoking inside your home to help improve the quality of your indoor air.

Ventilate Cooking Fumes

When cooking or heating your home with gas, tiny particles of Nitrogen Dioxide (NO2) are released into the air which can exacerbate respiratory symptoms of asthma in children. To avoid this and to reduce indoor pollution, use a vent or extractor fan when cooking and ensure that it is vented to the outside of the home, says Dr. Matsui. Alternatively, open a window to ventilate N02 emissions that way, or switch to using a cleaner source of energy, like electricity.

Remove Allergen Sources

For children who suffer a severe reaction to an indoor allergen, the only impactful way of improving symptoms is to remove the source of the allergen, says Dr. Matsui. “There are a variety of strategies that can help reduce exposure to that allergen/those allergens, but it is difficult to reduce allergen levels by a lot without removing the animal (or mold) that is the source of the allergen,” says Dr. Matsui.

Use an Air Filtration System

Studies have shown that some air filtration systems can be highly effective in reducing particulate matter, dust, and other allergens levels in the air, which can improve respiratory function in asthmatics. “Air filtration can help reduce air pollution levels and levels of virus in the air,” says Dr. Matsui. “Portable HEPA cleaners are also helpful if one that is appropriate for the room size is used.” Opt for a HEPA cleaner without any other features and keep it properly maintained, advises Dr. Matsui.

Dry Laundry Outdoors

In the colder, wetter winter months, many of us resort to drying our laundry indoors. However, experts have warned that this could be impacting our health, pointing to evidence that leaving wet washing indoors creates the perfect environment for mold and dust mites to thrive. A study from Scotland found that drying washing indoors increased moisture levels in the home by 30%, as one load of washing holds as much as 2 liters of water. To avoid this, use a tumble dryer or continue to dry clothes outdoors on sunnier days. If you do have to dry your laundry inside your home, open a window to allow ventilation.

Keep Dust and Pet Hair at Bay

The presence of dust mites can trigger asthma symptoms in those that suffer from it. Vacuuming regularly with an anti-allergen vacuum cleaner can help keep dust levels low, along with washing bed linen once a week and using anti-allergen pillows. Dust settles on surfaces and can become airborne when disturbed, so it might be a good idea to keep surfaces as clean and clear as you can if you have an asthmatic at home. And remember, dust mites thrive in humid conditions so try to make ventilating your home part of your daily routine.

Open a Window

Provided that the outside air is cleaner than the air indoors (which is the case for viruses like COVID-19), opening a window is an effective way to increase ventilation in your home, says Dr. Matsui. As well as reducing humidity levels, replacing indoor air with outdoor air will help improve your indoor air quality, especially when using products high in VOCs like paint or cleaning products. Airflow will help disperse these fumes.

Do Houseplants Really Purify Our Air?

Much has been written about how houseplants clean up and purify our indoor air, based largely on a 1989 study from NASA. However, some scientists have debunked this evidence, with one study from 2020 estimating that it would take between 10 and 1,000 house plants per meter square to achieve any real benefit. The EPA has also discounted houseplants as a means to combating indoor air pollution, pointing out that there is no solid evidence to support this. What’s more, they say that houseplants could inadvertently contribute to our pollution problem as they increase overall moisture levels, which creates the perfect environment for mold and other organisms to thrive.

What To Do If Your Child’s Health Is Being Impacted By Pollution

If you suspect that your child’s health is being impacted by indoor air pollution, there are two courses of action you should take, advises Dr. Matsui. The first step is to ask your child’s pediatrician whether it is likely that your child’s health is being adversely affected by indoor air quality. The second step is to not allow any smoking inside your home. If allergens are suspected of triggering symptoms, allergy testing will likely be carried out to identify which allergens are the culprits. This can be done by your pediatrician through blood testing or by a board-certified allergist who can do either blood testing or allergy skin testing. “If your pediatrician suspects your child has chronic respiratory symptoms, asthma, or allergies then the changes described above can be helpful,” says Dr. Matsui.

A Word From Verywell

Just because you can’t see indoor air pollution doesn’t mean that it doesn’t exist. While this can feel scary, there are plenty of practical changes we can all make to improve the quality of our indoor air.  Enforcing a strict smoking ban, keeping on top of the dusting, regularly vacuuming up any pet hair, using minimal cleaning products, and switching on the extractor fan when cooking are small tweaks that we can all make. And let’s not underestimate the benefit of simply opening a window to allow ventilation through your home. If you suspect your indoor air quality is poor, using an indoor air quality monitor might help give you a clearer picture. If you think that your indoor air quality could be making you or your family ill, discuss it with your medical provider or your child’s pediatrician.