The Relationship Between Pollution and Sleep
According to recent research from the University of Washington, extended exposure to air pollution negatively impacts our sleep.
But is it just air pollution that affects sleep, or do other environmental factors (and other types of pollution) play a role? You might be surprised to find that aggregate pollution levels do not significantly impact sleep.
How We Found Our Data
We compiled data from the American Lung Association, the EPA, and the Environment America Research & Policy Center. After normalizing and totaling the statistics for red air quality days, pounds of toxic water releases, and pounds of toxic waste management releases, we ranked each state by its overall pollution levels (per 1,000 people). We then correlated this information with sleep habit stats from the CDC and data about leading state industries from the Bureau of Labor Statistics to look for significant trends.
The verdict: Although aggregate pollution levels do not significantly impact sleep, certain types of pollution may be cause for concern. Specifically, we found that states with better air quality and less toxic water dumping tend to have more well-rested residents.
Which states are winning the fight against pollution?
Congrats goes to New Hampshire, which has the lowest overall pollution level (per 1000 people).
- Alaska has the highest overall pollution level, which may result from being a rural state with a sparse population.
- California, home to one of the most polluted cities in the country, has a surprisingly low pollution level. This is likely due to the fact that California is both densely populated and proactively implements anti-pollution measures.
- While not as surprising, this study found that waste management releases in each state are positively correlated with red air quality days in each state. In other words, the waste we create (and dispose of) directly impacts our air quality.
Air Quality & Toxic Water Make the Biggest Impact
Our research indicates that people sleep better in states with better air quality and less toxic water dumping. However, we also found that overall toxic release from waste management efforts do not appear to significantly impact sleep.
We found that a surprisingly high percentage — 44% — of Hawaiians sleep fewer than seven hours each night, even though Hawaii is one of the least-polluted states in the country.
Conversely, people in Utah and Idaho appeared in the top 10 states for sufficient sleep although they have relatively high levels of overall pollution. In fact, Vermont is the only state that hits the top 10 for both sufficient sleep and low overall pollution.
Leading Industries Can Indicate Pollution Levels & Sleep Habits
Our research suggests industry may play a part in both sleep time/quality and pollution levels. With a few exceptions, the leading industry in states that are high on sleep and low on pollution is healthcare and social assistance. Alternatively, the leading industry in states that are low on sleep and high on pollution is accommodations and food services.
These trends might be due to unrelated factors: For example, healthcare and social assistance is the top industry in more states than any other field, so based on volume alone it is more likely to show up in higher numbers on any list. Meanwhile, accommodations and food services jobs tend to involve demanding hours, which may result in less sleep regardless of pollution levels.
But sleep habits and pollution levels shared the closest connections when we compared them in the context of state industries — and that doesn’t seem like a coincidence.
Are We Adapting to Pollution?
In conclusion, our findings align with the University of Washington study about the impact poor air quality can have on sleep. Additionally, we found that other pollution indicators such as toxic water dumping might keep you up at night, although there was no significant correlation between overall pollution levels and sleep quality. This could mean we're either getting used to living in a polluted world or that our bodies haven’t been affected yet.
Whatever the case, it seems like taking care of the environment can't hurt a good night's sleep!