Air Quality and Sleep: What You Need to Know

Most of us know we need a dark and quiet bedroom for a good night’s sleep. But there’s one factor we often forget about: air quality. 

Air quality makes a difference to your sleep, and therefore a difference to your overall health and energy. But getting your air right can be tricky. 

Air quality can be worse at night, air pollutants like wildfires are becoming more common, and we’re particularly vulnerable to poor air quality while sleeping. 

That doesn’t mean you should give up on good sleep, though. 

Below, we dive into the key things you need to know about air quality and sleep, and how you can improve both. Plus, we’ll share how the RISE app can help you sleep better and get more energy, whatever quality of air you’re breathing.

Advice From a Sleep Doctor

“There’s still a lot we don’t know about air quality and sleep. From the studies that have been done, we know poor air quality can make it harder to fall asleep, wake you up in the night, and may cause breathing problems that disrupt your sleep,” says Dr. Chester Wu, who is double board certified in Psychiatry and Sleep Medicine, and provides sleep medicine services, medication management, and psychotherapy to adults at his private sleep medicine and psychiatry practice.

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Yes, air quality affects sleep, and that includes both indoor and outdoor air quality. Poor air quality can increase the time it takes you to fall asleep, cause you to wake up more often in the middle of the night, reduce your deep sleep, and cause breathing problems, sleep disorders, and stress, which can further disrupt sleep. 

Despite a lack of significant research into the link between air quality and sleep, we do know the negative impacts can be wide-ranging. 

One study shows that long-term exposure to outdoor pollution caused by traffic may be associated with shorter sleep duration. Another study found sleep efficiency — the measure of how long you spend sleeping while in bed — may be reduced when there are short-term elevations in particulate matter, which are tiny particles in the air. 

And another study found that when children in Peru slept with less air pollution from cooking stoves in their homes, they fell asleep more easily and symptoms like a sore throat and morning headache improved.

Research shows pollutants in the air can inflame your airways, leading to respiratory problems and potentially worsening obstructive sleep apnea. And a 2020 review found an overall adverse effect of pollutants on sleep health, including some studies that have found increased sleep-disordered breathing, including snoring and sleep apnea. However, there are mixed studies and a definitive correlation remains uncertain.

There are several air pollutants that can negatively impact your sleep. 

Particulate Matter 

Particulate matter are fine particles in the air. They’re often referred to as PM2.5 or PM10, which stands for particulate matter with a diameter of 2.5 microns or 10 microns or less. 

These tiny particles can get deep into your respiratory system and bloodstream, causing irritation, inflammation, and shortness of breath. When these symptoms hit, you may find it harder to fall and stay asleep. 

And if you already have breathing issues, like asthma, your condition may be aggravated further — which won’t help your sleep. 

Carbon Dioxide 

It’s not just particles in the air that can ruin your sleep. Gasses in the air can also have an effect. 

High levels of carbon dioxide, which can happen when you sleep with the doors and windows closed, can make a difference to how well you sleep at night. 

A 2020 study tracked participants’ sleep with both wearable sensors and questionnaires. It found higher carbon dioxide levels were linked to less deep sleep. Deep sleep was reduced by 4.3% for every 100 parts per million (ppm) increase in mean carbon dioxide concentration. 

And another study, also from 2020, found higher carbon dioxide levels were linked to longer sleep latencies (taking longer to fall asleep).

A 2023 study tracked the sleep of 62 participants over the course of two weeks. It found higher levels of air pollution in their bedrooms, carbon dioxide, noise, and temperature were all linked independently to lower sleep efficiency.  

For air quality in particular, high carbon dioxide was linked to a 4% decline in sleep efficiency compared to low carbon dioxide. This was more disruptive than temperature, which caused a 3.4% decline. High particulate matter caused a 3.2% decline compared to low particulate matter exposure. 

And a 2022 study looked at how indoor air quality affected the sleep of students. The results showed that poor perceived sleep quality was linked to higher carbon dioxide levels while sleeping.  

The link goes both ways, too. One study found lower levels of carbon dioxide were linked to better sleep quality and improved next-day mental performance and energy levels. 

Carbon dioxide isn’t the only gas causing sleep problems, though. Exposure to high levels of nitrogen dioxide may also be linked to sleep-disordered breathing and an increased risk of sleep apnea.

Allergens

If your air is clogged with pollen, dust, or pet dander, you may also suffer from allergies. This can lead to symptoms like a stuffy nose, sneezing, and wheezing — which won’t make sleeping any easier. 

And research shows those who suffer from allergic rhinitis (cold-like symptoms from allergies) have trouble falling asleep, wake up often, snore, and have lower self-reported sleep quality.   

If you’ve got asthma, cockroaches, cats, dogs, and fungal contaminations can make it worse. And dust mites can increase your odds of developing asthma in the first place. 

Allergens in the air can also lead to nasal congestion and mouth breathing, and mouth breathing can lead to everything from bad breath and low energy to brain fog and high blood pressure.  

Stress About Air Quality 

Air quality may also indirectly affect your sleep. If you’re worried about it — which you probably are if you’re reading this article — this worry can keep you up at night and cause sleep problems like insomnia. 

RISE users say stress and anxiety are the biggest factors stopping them from getting a good night’s sleep. You could be stressed about wildfires and smokey air, the health impacts of poor air quality if you’re sensitive to it (and even if you’re not), or simply be getting anxious reading the many news stories out there about worsening air quality. 

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More Research is Needed

We know poor air quality doesn’t bode well for good sleep health. But more research is needed to fully understand the link and to find the best way to protect our quality of life. 

This is especially important as global warming and wildfires become more of a problem and air quality becomes a greater public health concern. 

Poor air quality can be even more dangerous for children, pregnant women, older adults, and those with asthma, diabetes, or heart conditions. But even for those of us who aren’t vulnerable, worsening air quality can start impacting our sleep, which impacts everything else: our energy, our physical health, and our mental well-being.

So far, studies on air quality and sleep are hard to compare as they vary in geographic location, season, type of home, and ventilation — just to name a few factors. And measuring air quality during sleep is tricky as instruments can make noise, which can disrupt sleep, or participants know if a window or door is open or not, affecting results.

Plus, some studies measure subjective sleep quality, which can vary from person to person, and there’s no one definition of sleep quality yet.

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Air quality can be worse in your bedroom compared to elsewhere in your home for several reasons. 

• You spend more time in your bedroom 
• Your bedroom is not a well-ventilated room 
• There are pollutants in your bedroom you don’t find elsewhere 
• Outdoor air quality can be worse at night 

Firstly, you spend long periods of time in your bedroom. During the day, you’re probably moving around between rooms in your house, your office, outside, and other places. At night, you’re mainly exposed to the air in your bedroom. 

Even if your exposure to pollutants is low, you (hopefully) spend about eight hours sleeping in your bedroom. That’s about a third of your life. This means low levels of pollutants can still affect your health, energy, and performance as you’re spending more time breathing them in. 

Secondly, your bedroom is probably not well-ventilated. Most of us close our bedroom door while sleeping and we may keep our windows closed if it’s cold or noisy outside. But this decreases ventilation, which can increase carbon dioxide levels and trap allergens inside. 

Thirdly, there are air pollutants in your bedroom that you won’t find elsewhere. Your mattress, pillows, and bedding collect dust and dust mites, and may emit chemicals that can affect your health. If you light a candle before bed, this too can decrease your bedroom air quality. 

And while not strictly in your bedroom, you may have just cooked, swept, or dusted before bed, which can decrease air quality in your home. 

Finally, outside air quality can be worse at night. The air is cooler, so there’s less movement. With less wind, pollutants hover and settle near the ground. And some plant species release more pollen at night, meaning your allergies can be worse at night. If you sleep with your windows open, this can cause your indoor air quality to get worse at night, too. 

And it’s worse if you’re a smoker. Research shows even when smokers smoke outdoors, they’re still exposed to more air pollution in their bedrooms. This is because smokers exhale pollutants from their lungs. Smokers’ bedrooms were found to have higher levels of carbon monoxide, formaldehyde, and particulate matter than non-smokers. 

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Improve air quality in your bedroom by opening or closing windows (depending on the quality of the air outside), using an air filter, and reducing the build-up of allergens as much as you can. 

Here’s what to do. 

• Open or close your windows: Keep your windows closed when the outside air quality is poor. You can check this on airnow.gov. If the air outside isn’t too polluted, consider opening windows at night to increase ventilation. If it’s too noisy out, you could open windows during the day only.
• Use an air filter: A HEPA filter can remove dust mites, pollen, particles, and pet allergens from the air in your bedroom. Keep your HVAC system clean and maintained, as it can harbor dust and mold. You may need to change your air filter more often if the air quality in your area is bad.
• Get the humidity levels right: You don’t want the air to be too humid or too dry. Mold thrives in humid environments, but dry air can cause congestion. Depending on where you live, you may need a humidifier or a dehumidifier. A 2018 meta-analysis says relative humidity should be 40% to 60%. But the EPA recommends between 30% and 50%.
• Open your bedroom door: This tip isn’t for everyone. But one study found sleeping with the door and windows closed leads to the highest levels of carbon dioxide, carbon monoxide, and volatile organic compounds compared to sleeping with one or both open. Sleeping with your bedroom door open may help, but this may also let pollutants in from other rooms in your house, like your kitchen. Beyond pollutants, opening your bedroom door might mean noise and light from your family elsewhere in your house disrupts your sleep, so it depends on your living situation whether opening the door will help or hurt your sleep. 
• Don’t let your pet sleep in your bed: Ideally, pets should sleep in a different room from you. But at the very least, not in your bed. If you do share a bed with a furry friend, make sure you’re washing your bedding regularly to reduce allergy symptoms. 
• Shower before bed: Wash off any pollen and pet dander that might be in your hair or on your skin before climbing into bed. Go a step further and take your shoes off at the door before coming into your home and washing any clothes you’ve worn around animals or out in pollen season as soon as you get home. 
• Clean your bed sheets, bedroom, and entire home regularly: Wash your bedding once a week in 130-degree Fahrenheit water, vacuum your home often, and use a wet cloth to capture dust, rather than brushing it into the air where it’ll resettle. Finally, treat any mold as soon as you spot it in your home. 
• Avoid making indoor air quality worse: We can’t do much about outdoor air quality, but at home, avoid perfumes, candles, incense, and room deodorizers, which can lower your air quality. 
• Upgrade your bed and bedding: Experiment with the best mattress and pillow position for you. This may change if your breathing is impacted when air quality declines. And consider investing in a hypoallergenic pillowcase and mattress. For your mattress, opt for layers of foam or latex, which are better at resisting dust mites, mildew, and mold. Avoid fiberglass mattresses. They may be flame resistant, but they can cause poor air quality if fiberglass fibers get loose. Go for wool, cotton, or polyurethane foam instead.

Heads-up: You can check outdoor air quality on airnow.gov. It’ll give you the air quality index (AQI) in your area. AQI is measured on a scale from 0 to 500. Scores below 50 indicate good air quality, whereas anything above 300 poses a health threat to everyone — even those of us usually not vulnerable to air pollution. 

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There’s only so much you can control when it comes to air quality. Perhaps there’s a wildfire, you live in a smoggy city, or you live with a smoker. Do what you can to improve your air quality, and focus on improving your sleep hygiene to get better sleep, no matter what you’re breathing. 

Sleep hygiene is the name for the daily habits you can do to help you fall and stay asleep more easily. With good sleep hygiene, you can make sure nothing else gets in the way of good sleep. Even if you consider your sleep hygiene pretty good already, worsening air quality means more and more of us need to pay more attention to our sleep habits.

One thing to be aware of with sleep hygiene is you may need to make some trade-offs when the air quality is poor and consider what disturbs your sleep the most. 

Here’s what good sleep hygiene looks like: 

• Get out in bright light in the morning: Morning light resets your circadian rhythm, or body clock, for the day, helping to keep your sleep cycle in check. Spend at least 10 minutes out in natural light, or 15 to 20 minutes if it’s overcast or you’re getting light through a window. If a high pollen count or wildfire smoke are affecting your area, consider staying inside and either getting light through a window or from a light therapy lamp. Sit about 16 to 24 inches from a 10,000 lux light therapy lamp for 30 minutes in the morning.
• Avoid light close to bedtime: Light suppresses the sleep hormone melatonin. About 90 minutes before bed, turn down the lights and put on blue-light blocking glasses (we recommend these).
• Avoid caffeine, large meals, intense exercise, and alcohol too late in the day: All four can disrupt your sleep. Check RISE for when to avoid each one daily.
• ‍Do a calming bedtime routine: Don’t let stress over poor air quality keep you awake. Do relaxing activities in the run-up to bedtime, such as reading, yoga, journaling, or breathing exercises. This can be helpful any night, but you might find you need a little more time to unwind before bed when you’ve been reading news about wildfires or worrying about poor air quality. Give yourself that time to ensure stress doesn’t impact your sleep. 
• ‍Keep your bedroom dark, cool, and quiet: Aim for 65 to 68 degrees Fahrenheit, use blackout curtains and an eye mask, and wear earplugs or use a white noise machine or white noise app like RISE. Remember, in your pursuit of better air quality, you don’t want to sacrifice a cool, dark, quiet room. Opening the window may improve your air quality, but it may make your bedroom too warm or noisy. On the other hand, you don’t want to solely focus on making your bedroom cool, dark, and quiet, and make your air quality worse in the process. All four are important for sleep.

To stay on top of your sleep hygiene each day, the RISE app can guide you through 20+ habits and tell you the best time to do each one to make them more effective.

RISE users on iOS 1.202 and above can set up their 20+ in-app habit notifications here. 

Expert tip: Focus on your sleep debt. Sleep debt is the running total of how much sleep you owe your body. It’s compared to your sleep need, the genetically determined amount of sleep you need. 

For the best health, mental performance, and energy levels, you want your overall sleep debt to be as low as possible. If poor air quality is making it hard to get enough sleep at night, try catching up on sleep with daytime naps. And focus on paying back sleep debt (by sleeping a little longer at night) when your air quality improves. 

And check your sleep debt when making changes to see what helps and hurts your sleep the most. For example, you might find opening a window to improve air quality actually causes more sleep loss as it’s noisy where you live. 

RISE can work out how much sleep debt you have. We recommend you keep this below five hours to feel your best each day. 

But this tip isn’t just for when air quality is bad. Air quality can change fast. Wildfires, for example, are hard to forecast. Current technology can generally only predict a wildfire about a day out, meaning you can never really know when your air quality (and sleep) is about to take a hit. 

Keeping your sleep debt low, even when air is good, means you’ll be able to better manage any sleep disruption that comes your way if air quality suddenly declines.  

RISE can also tell you how much sleep you individually need. And no, it’s not just eight hours for everyone. Among 1.95 million RISE users aged 24 and up, sleep needs ranged from five hours to 11 hours 30 minutes. 

RISE users on iOS 1.202 and above can click view their sleep need here and view their sleep debt here.

Breathe Easy at Night 

Poor air quality can make it harder to get the sleep you need to feel your best each day. But there are a few things you can do to improve the air quality in your bedroom. Try investing in an air purifier, opening your windows (if outdoor air quality is good), and cleaning your bedroom often to clear out allergens. 

Whether you’re breathing good quality air or not, pay attention to your sleep hygiene. This can make it easier to fall and stay asleep. 

The RISE app can guide you through 20+ sleep hygiene habits each day. RISE can also work out how much sleep debt you have and help you keep it low to keep your energy high. 

Sleep hygiene can make a real difference — and fast. We’ve found 80% of RISE users have better sleep within five days.