New research indicates that increased air pollution is linked to a rise in night-time coughing, potentially disrupting sleep. This study, led by Professor Cecilia Mascolo from the University of Cambridge, suggests that daily symptoms of harmful emissions may be overlooked.
Researchers analysed anonymised data from a commonly used sleep app over 18 months, covering an average of 98,000 people nightly across 32 cities in 12 countries. The app tracked both sleep and cough frequency, revealing that about half of the participants coughed during the night.
High daily particle pollution was consistently associated with increased night-time coughing. This link was observed even at concentrations below the World Health Organization's air pollution guidelines. For example, night-time coughing increased by 13% during the Los Angeles wildfires, and increased coughing was also noted in London around Guy Fawkes fireworks and bonfires in November 2025.
The findings suggest that continued efforts to reduce air pollution are warranted, even in cities with relatively low pollution levels.