Study after study shows that Americans are a chronically exhausted lot, and it turns out that lack of sleep may not be the only thing to blame.
Even though about 60 million Americans suffer from either sleep disorders or sleep deprivation, one study has found that air pollution may also be a factor into why our nation isn’t as well rested as it once was.
A new study by the University of Washington has found that there may be a link between air pollution and sleep quality. The study was presented at the American Thoracic Society’s annual international conference earlier this month, where researchers discussed how air pollution can negatively affect sleep efficiency for all Americans, despite their sex, income, and location.
In short: even if you get the recommended amount of lightly sleep, polluted air could still leave you feeling groggy come morning.
Researchers utilized data collected from six cities nationwide and analyzed the sleep patterns of 1,863 participants from the last five years. The study spanned over seven days, and the researchers found that those breathing in high levels of nitrogen dioxide typically had a lower sleep quality than those surrounded by clean air.
The study was relatively simple — the sleepers had to wear a special sleep device on their wrist every night when they went to bed. The watch-like accessory monitored their sleeping habits, how many hours they spent awake and asleep, and tracked each participant’s movements while sleeping. When all the data was compiled, the researchers found that the top tier of sleepers had 93% sleep efficiency, and the bottom tier had 88%.
With these two numbers in mind, the researchers filtered the participants into four groups based on their exposure to air pollution. After they filtered out factors such as age, smoking habits, and if the participant suffered from obstructive sleep apnea, they found that those living in areas of high pollution were most likely to fall into the lowest sleep efficiency tier.
In addition, the researchers found that the exposure to high levels of nitrogen dioxide increased each participant’s chances of having a lower sleep quality by a staggering 60%.
Dr. Martha Billings, the study’s lead author, explains in a statement to Newsweek how exactly the body is affected by being exposed to air pollution over time. She says:
“Prior studies have shown that air pollution impacts heart health and affects breathing and lung function, but less is known about whether air pollution affects sleep. We thought an effect was likely given that air pollution causes upper airway irritation, swelling and congestion, and may also affect the central nervous system and brain areas that control breathing patterns and sleep.”
For the next step in their research, scientists are going to continue to look at the connection between additional air pollutants and sleep quality, as they believe data from only a week of sleep may not be an accurate representation of a person’s overall sleep pattern.