In brief
On 10 November 2026, fireworks and bonfires scattered during Bonfire Night sparked high levels of air pollution across southeast England, with PM2.5 spiking to near‑hazardous concentrations in London. Met Office maps and Sky News reports show soot particles trapped in fog, increasing risk to people with asthma and heart disease. The incident has raised questions about future emissions and regulatory responses.
Fireworks and bonfires unleashed dangerous concentrations of fine particulate matter across southeast England on Monday, 10 November 2026, as reported by Xinhua and corroborated by Sky News and the Met Office.
Sky News detailed that the celebrations on Thursday, 7 November, included both fireworks displays and bonfire events, and that the aftermath saw PM2.5 levels spiking in several areas. In Hillingdon, London, concentrations rose to approximately 600 units, well above the 24‑hour average threshold of 15 units recommended by the World Health Organization.
Met Office maps illustrated a sharp increase in fine particulate matter across the region. The finding is noted on a 10‑point scale that reached the maximum of 10 in London, indicating a severe pollution episode. The thick fog that enveloped the capital also played a role, trapping soot particles close to the ground.
High pressure was cited as the culprit behind the stagnant atmospheric conditions. “If we pop pollution into the atmosphere, whether that's from cars, industries, fireworks, or bonfires, that pollution doesn’t go anywhere,” said Liz Bentley, chief executive of Britain’s Royal Meteorological Society, in a statement to Xinhua.
According to Imperial College London, the soot particles released by fireworks and bonfires are about 30 times smaller than the width of a human hair. These fine particles can penetrate deep into lungs, enter the bloodstream, and raise the risk of heart attacks and strokes, particularly for those with pre‑existing conditions.
Asthma‑prone and heart‑suffered individuals were highlighted as most vulnerable. The WHO’s advisory threshold of 15 units for PM2.5 suggests that the recorded levels pose an immediate health risk for these groups.
Uncertainty remains regarding the full extent of short‑term and long‑term health impacts from this particular pollution episode. While the WHO guideline offers a baseline, the exact physiological effects of the 600‑unit peak in Hillingdon are still being investigated. The Royal Meteorological Society’s comment on stagnant conditions suggests that future pollution episodes could be influenced by similar weather patterns, but the frequency and severity of such episodes remain uncertain.
