Chronological coverage updated 2nd October 2026 06:00.
Update 1 · 2nd October 2026
Spikes in Air Pollution Cause Night-Time Coughing and Sleep Disturbance, Study Finds
A multinational study led by the University of Cambridge has established a direct link between daily fluctuations in air pollution and increased night-time coughing, revealing how routine atmospheric pollution disrupts sleep patterns across urban populations.
While most public health research focuses on acute pollution events severe enough to warrant hospital admissions, this project tracked day-to-day respiratory symptoms by analyzing anonymised data collected over 18 months from a popular sleep-tracking application. The dataset covered 32 cities across 12 countries, averaging roughly 98,000 active users per night.
App Data and Environmental Correlations
The Guardian reportedly quoted Prof Cecilia Mascolo (study lead from the University of Cambridge) as saying: “I come from an area in Italy with very high pollution and I am very aware of its not-talked-about effects.”.
Analysis showed that approximately half of app users coughed at least once during the night, while 1% coughed more than 10 times. The highest cough frequencies were consistently recorded in Milan and nearby Monza, situated in Northern Italy's Po Valley.
The Guardian reportedly quoted Dr Tong Xia (research team member now at Tsinghua University) as saying: “I thought that adding in the confounding factor of flu season would make the link in the data disappear, but it didn’t.”.
Specific Pollution Events and Low-Concentration Effects
The study recorded notable surges in nocturnal coughing during localized pollution events, such as Bonfire Night celebrations in London during November 2025 and wildfire events in California.
Night-time coughing rates surged by 13% during smoke spikes caused by the Los Angeles wildfires..
37% of UK adults aged 18 to 30 use sleep applications, and more than 40% of all UK adults track their sleep using digital technology..
The Guardian reportedly quoted Prof Cecilia Mascolo (study lead from the University of Cambridge) as saying: “Even in cities with relatively low levels of air pollution, such as Melbourne and Sydney, we observed positive associations between particle pollution and increased coughing.”.
- Air pollution directly triggers night-time coughing, interrupting sleep quality across major global cities.
- Wildfires and localized firework displays created measurable spikes in airway irritation and sleep disturbance.
- Researchers advocate for continued pollution mitigation beyond legal thresholds to protect long-term public health.
