Five Key Factors Affecting Your Indoor Air Quality

Your indoor air quality is important and knowing what affects it is critical to the health of your home.

It’s common knowledge that air pollution is a health hazard to humans and animals. And while we usually think of air pollution as outdoor smoke and fumes, the Environmental Protection Agency reports that we spend approximately 90% of our time indoors, which means that the air quality in our homes is just as (if not more) important. Exposure to poor air quality indoors can produce minor symptoms like headaches, fatigue, and skin irritation. But it can also result in major health consequences, like respiratory illness, heart disease, and cancer.

That said, the first step to improving the air you breathe is knowing what affects it. Here are five key factors that contribute to the state of your home’s air quality:

Dust and other airborne particles

Dust is a combination of indoor and outdoor matter, such as soil, pet dander, and dead skin. Along with other airborne particles, it floats in the air and settles on surfaces. When you breathe in small doses of dust, you may experience sneezing, nasal congestion, and itchy eyes, ears, or throat. But in large concentrations, people with high sensitivities to dust can suffer from shortness of breath, tightening of the chest, or even sleep deprivation due to difficulties in breathing.

Easy steps like vacuuming regularly, using microfiber cloths for wiping surfaces, and changing your sheets weekly can help reduce the amount of dust indoors. In addition, tools like the MERV 13 air filter can also keep your home free of dust and other microscopic particles, like pollen and smoke.


Microbial growth is another sign that you need to amp up your indoor air quality solutions. Plumbing issues are usually to blame for the growth of mildew and mold, as they cause excess moisture in floors, walls, and ceilings. In particular, HomeServe explains that mold thrives in these damp conditions, which can be due to hidden leaks and poor drainage systems. Exposure to mold does not only cause allergic reactions, it is also known to increase the risk of respiratory problems and trigger asthma attacks in individuals.

To solve this problem, homeowners need to go to the source and address their plumbing issues right away. This might mean contacting professionals and installing detection tools that can prevent future leaks.


The chemicals we use to keep a home clean and orderly may be doing more harm than good. Some might even contain Volatile Organic Compounds, or VOCs, which become trapped in a home’s foundations for many months. Some VOCs can be very harmful, particularly formaldehyde and benzene. These can be found in paints, aerosol sprays, and wood preservatives.

The simple solution is to switch from chemical-based treatments to organic products. Ditch the bleach for cleaning and go for homemade solutions like your very own mix of baking soda, vinegar, and lemon juice.


Ideally, a home should have 30-50% relative humidity. That's because residents can experience eye irritation and several skin symptoms when it is too dry. This is most common during the winter months. Conversely, an indoor environment that’s too humid can breed microbes, which we’ve already covered as bad for one’s health.

Installing a humidifier is an easy hack as most gadgets allow you to set the ideal range for your home. Alternatively, you can use a dehumidifier if there is too much moisture in the air. Or, try cracking open a window or turning on the exhaust for even simpler solutions.


If you’re experiencing headaches, hypersensitivity, and fatigue, it may be a sign of high carbon dioxide levels in your home due to poor ventilation. Live Science highlights a study on the effects of too much carbon dioxide in the air, which includes impaired cognitive abilities and decision-making skills. Other than the physical symptoms, it may contribute to psychological distress and strain individual relationships.

Other than dedicated heating and cooling systems, one simple way to improve ventilation is to let the outdoor air in — provided that its quality isn’t compromised. Otherwise, you can opt for a reliable home ventilation system that isn’t affected by what the air is like outside your home.

For figuring out the next steps, check out our article How to Test The Air Quality in Your Home for deeper insight into improving your home life.

Alec Lower

Content Writer

Alec is a third-year member of the team at Second Nature. He brings expert knowledge of a myriad of home air filtration topics including HVAC filters, filtration efficiency, and indoor air quality.