The list of health problems linked to air pollution is long and disturbing, and it seems to grow a little longer every week. Studies have previously connected air pollution with an increased risk of lung and heart disease, type 2 diabetes and premature death, and this week there’s news that air pollution is screwing with your sleep – which in itself can cause health problems.
Presented at the American Thoracic Society’s annual conference, the study used data tracking to measure the levels of nitrogen dioxide and PM2.5 particulates in six US cities over a five-year period. It then compared these against the sleep efficiency of 1,863 people living in these areas.
Sleep efficiency is a measure of how much of a person’s time in bed is spent asleep and awake. Each participant’s sleep efficiency was tracked over seven consecutive days using medical-grade devices worn on the wrist.
The participants were broken up into four groups based on their sleep efficiency. The top group had a sleep efficiency of 93% or higher, while the bottom group’s sleep efficiency was 88% or less.
Those who were exposed to the highest levels of air pollution were more likely to be in the bottom group for sleep efficiency. High levels of nitrogen dioxide increased the chances of having low sleep efficiency by 60% and high levels of PM2.5s by 50%.
The negative effects of air pollution on sleep could be linked to the breathing issues it causes.
“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,” said lead author Martha E Billings, assistant professor of medicine at the University of Washington.
Short-term effect of substandard sleep efficiency are low mood and poor memory, and it can also affect co-ordination, leading to accidents. In the long term it can have a seriously negative effect in health, contributing to heart disease, diabetes and even early mortality.
However, the study did not prove a link between air pollution and poor sleep. Other factors not associated with air pollution could have played their part in the poor sleep on show, such as noise from traffic. And as the participants’ sleep was only measured over seven days it might not be a comprehensive account of their sleep patterns.
That said, it seems increasingly clear that air pollution could be messing with the body in a variety of ways that no-one expected. If a study saying it causes baldness and/or erectile dysfunction is published next week, don’t say we didn’t warn you.