Indoor Air Quality

Good indoor air quality is an important part of asthma and allergy management. When you’re managing asthma and allergies, take steps to make sure your indoor air is well-ventilated and has a lower amount of pollution, indoor allergens and other irritants.

What Is Indoor Air Quality?

Air contains different types of particles. These particles are a mix of gases (like carbon dioxide and volatile organic compounds), small solid particles (like dust and pollen), and small liquid droplets (like water). Some particles in the air may harm human health or the environment. The type and amount of particles in the air can affect your indoor air quality.

Particles in indoor air that can be harmful include:

• Allergens
• Mold
• Chemicals, scents, and volatile organic compounds (VOCs)
• Smoke and fumes
• Certain gases like ozone, radon, and carbon monoxide
• Outdoor air pollution that gets trapped inside buildings

What Affects Indoor Air Quality?

Four factors affect indoor air quality:

• Ventilation
• Filtration
• Humidity
• Sources of pollution, allergens, and irritants

Ventilation

When a building or enclosed space has poor ventilation, it traps the air inside. This can make the indoor air more polluted and irritating than outdoor air.  Poor ventilation can also cause more moisture (higher humidity levels) inside.

When a building has good ventilation, fresh air is brought indoors, and indoor pollution moves outdoors.

Filtration

Central heating and air conditioning systems have filters to trap dust and other particles (pollution). Portable air cleaners also filter the air in the room where they are located.

Filters need to be changed or cleaned regularly as per manufacturer’s recommendations.

Allergens

Indoor air can have a lot of allergens, such as dust mites, pollen, cockroaches, and mold. These substances irritate the airways of people with allergies and asthma. They can also trigger other symptoms like skin rashes.

Humidity

Humid air creates small liquid droplets that can trap pollutants and worsen air quality.

Mold and dust mites thrive in environments that have increased moisture. Keep the indoor relative humidity levels between 30-50% to reduce mold and dust mite levels.

Scents, Chemicals, and Other Sources of Indoor Air Pollution

Scents, both pleasant and smelly, can affect your indoor air quality. Any kind of scent can potentially  trigger asthma symptoms. These can include scented candles, fragranced potpourri, perfumes, wax warmers, and cleaning supplies.

Some other items in your home can release gases called volatile organic compounds (VOCs). This is called off-gassing. VOCs can be 2 to 5 times higher indoors than outdoors.² VOCs can have some short-term adverse effects, but experts aren’t sure yet of long-term adverse effects.

Sources of VOCs can include:

• New furniture
• New mattresses
• New carpet
• New building materials
• Paint and varnish
• Cleaning supplies
• Air fresheners
• Pesticides

Other sources of indoor air pollution include:

• Fuel-burning heat sources (like wood-burning stoves, gas fireplaces, kerosene heaters)
• Smoke from gas cooktops, candles, or tobacco use (e.g., cigarette smoking)
• Attached garages that store cars, motorcycles, or lawnmowers can add carbon monoxide to your air
• Radon (a gas that comes from the ground, gets trapped in a home, and can rise to dangerous levels)
• Ozone produced by ionizing air cleaners and emitted by office equipment is a lung irritant and can worsen asthma

Outdoor Air Pollution

Outdoor air pollution is caused by particles and gases that are not normally part of the air. This can come from pollen, smoke, dust, ozone, and emissions from cars and factories. All of these can create poor outdoor air quality.

Bad outdoor air quality can make asthma and allergies worse.  Outdoor air can easily enter your home by coming  through leaks around doors and windows. It can also come in every time you open a window or door. In addition, you can bring pollen and smoke particles inside on your clothing.

Allergens, scents, chemicals, and outdoor air in your home all work together to negatively affect your indoor air quality.

How Does Indoor Air Quality Affect My Health?

Good indoor air quality is an important part of asthma and allergy management. Having your asthma and allergies under control can help you breathe better, sleep better, be more active, and be healthier overall. All of these things can improve your overall quality of life.

If you are constantly in a space – such as your home, work, or school – that has poor indoor air quality, it may have a negative impact on your health. You may have trouble keeping your asthma and allergies under control. You may have more asthma attacks, emergency room visits, or even hospital stays.

Some indoor air pollutants – such as tobacco smoke and radon – can have other serious effects on your health and can cause cancer.

Air quality in schools is a serious concern. At school, children are often exposed to allergens such as dust mites, animal dander, and mold. Harsh cleaners and scents, as well as fumes from idling buses, can trigger asthma symptoms. Respiratory infections, which can trigger asthma symptoms, tend to spread more during school months, especially during the fall and winter.

Exposure to asthma triggers at school may result in asthma that is harder to control, is associated with poorer school performance, and can lead to an increase in missed school days.

Workplaces can have poor indoor air quality too. This can lead to occupational asthma. Any work that causes small particles to enter the air can lead to poor air quality in the workplace. These small airborne particles can get breathed into the lungs and cause problems (e.g., tightening and inflammation of the airways). For example, bakers may inhale small airborne particles of flour. This can affect the lungs and cause occupational asthma (otherwise known as baker’s asthma).

Poor indoor air quality in the workplace also affects more than our lungs. It can also impact mental function, ability to focus, and work productivity.³

How Can I Improve My Indoor Air Quality in My Home?

Here are 10 ways you can reduce the sources of allergens and irritants throughout your home:

1. Set up regular cleaning routines.
2. Vacuum carpets weekly. Replace carpets with solid flooring (like hardwood or laminate flooring) when/if possible.
3. Wash bedding and throw rugs weekly in hot water.
4. Remove strong scents. Use unscented, gentle cleaners. Don’t use scented candles, wax warmers, plugins, and potpourri.
5. Fix leaks as soon as possible.
6. Have everyone take off their shoes when they enter your home.
7. Keep pets out of bedrooms. Wipe pets down with a towel after they have been outside. Bathe them weekly if they tolerate it.
8. Keep your home’s humidity levels between 30 and 50%. If you live in a wet climate, consider using a dehumidifier to reduce the moisture in your home. This will help to reduce dust mites and prevent mold growth.
9. Keep windows closed during peak pollen times or during times of high outdoor pollution, if possible.
10. Use HEPA filters on your heating/cooling systems and portable HEPA air cleaners.

Healthier Home Checklist – Use our interactive Healthier Home Checklist to help you improve your indoor air quality and reduce allergy and asthma triggers around your home.

How Can I Improve My Indoor Air Quality in My School?

Here are 10 steps school staff can do to help improve indoor air quality, such as:

1. Don’t allow buses to idle near school buildings.
2. Use only district-approved, unscented and low-VOC cleaning products and methods.
3. Don’t use scented candles, scent or essential oil diffusers, or scented personal hygiene products (e.g., perfumes, colognes, soaps, and lotions).
4. Don’t allow warm-blooded pets in classrooms.
5. Fix leaks immediately before they have the chance to grow mold.
6. Do not use air cleaners with ionizing features or that release harmful levels of ozone.
7. Keep windows closed when pollen is high or outdoor air quality is poor, if possible.
8. Keep humidity between 30 to 50% to reduce dust mites and help prevent mold growth.
9. Use integrated pest management as a way of controlling pests such as cockroaches and mice.
10. Do regular maintenance, cleaning, and filter replacement on the central heating and cooling systems. Consider portable HEPA air cleaners in rooms with poor ventilation.

The Environmental Protection Agency (EPA) also offers several resources for school staff who want to learn more about creating healthy indoor school environments.

How Can I Improve My Indoor Air Quality in My Workplace?

To reduce work absences due to asthma, employers can improve air quality in the workplace by taking these 10 steps:

1. Improve ventilation in indoor spaces and use appropriate and effective air cleaning and air filtration devices to remove small particles from the air.
2. Create a policy for employees that discourages strong scents/odors (no heavy perfume, cologne, essential oils, potpourri, etc.).
3. Provide appropriate masks for workers exposed to high levels of air pollution (such as N95 respirators).
4. Schedule cleaning and dusting to occur when employees with asthma are not around.
5. Reduce overall emissions, fuel burning, and exhaust fumes in and around the workplace.
6. Encourage employees to go tobacco smoke and e-cigarette free (offer incentives!) and create a no-smoking zone around the workplace.
7. Reduce excess moisture that may be causing mold growth indoors.
8. Use appropriate pest control to reduce cockroach and mouse infestation.
9. Install air quality sensors to monitor your workplace’s indoor air quality.
10. Do regular maintenance, cleaning, and filter replacement on the central heating and cooling systems. Consider portable HEPA air cleaners in areas with poor ventilation.