Increased air pollution linked to more night-time coughing, UK-led study finds — SkimNews
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- University of Cambridge researchers found high daily particle pollution was consistently associated with increased night-time coughing, with effects observed at concentrations well below WHO air pollution guidelines.
- The study drew on anonymized data from a sleep app covering 32 cities across 12 countries, averaging 98,000 people per night over 18 months; about half of all participants coughed during the night and 1% coughed more than 10 times.
- The Po Valley in northern Italy (Milan and Monza) recorded the greatest frequency of night-time coughing, one of the most polluted areas in western Europe.
- Night-time coughing increased 13% during the LA wildfires smoke, the clearest and most severe pollution spike in the study window, with some people experiencing effects delayed by several days.
- Lead researcher Prof Cecilia Mascolo and Dr Tong Xia (now at Tsinghua University) found that during the first week of November 2025 in London, days with PM2.5 exceeding WHO guidelines coincided with noticeably higher cough rates, possibly linked to Guy Fawkes fireworks and bonfires.
- Even in relatively low-pollution cities like Melbourne and Sydney, researchers observed positive associations between particle pollution and increased coughing, and Dr Xia said the link persisted even after accounting for flu season.
Why it matters: The findings suggest legal air pollution limits pegged near WHO guidelines may not be protective enough, since night-time coughing rose even at lower concentrations and in relatively clean cities like Melbourne and Sydney. Mascolo argues regulators should keep reducing particulate pollution rather than treating compliance as the finish line, a stance now backed by 18 months of crowd-sourced data from 98,000 people a night.
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