In brief
Bright fireworks on Bonfire Night led to a surge of fine particulate matter (PM2.5) across southeast England, especially London. Levels spiked to 600 units in Hillingdon, vastly exceeding World Health Organization limits and earning the highest score on a 10‑point pollution scale. High pressure trapped the soot, causing health concerns for asthma and heart‑condition sufferers.
On Monday, bright fireworks and bonfires that celebrated Bonfire Night turned east coast skies over England into a cloud of smoke that scientists say will affect thousands of people.
Met Office radar maps published by Sky News showed that southeastern England, and especially London, filled with fine soot particles described as “PM2.5.” In the Hillingdon borough of London the readings rose to about 600 units, the highest on the 10‑point scale that the Met Office uses to gauge daily air quality.
The World Health Organization says that a 24‑hour average of fine particulate matter should not exceed 15 units. The particles released by fireworks are 30 times smaller than the width of a human hair, meaning they can curl deep into the lungs and even enter the bloodstream, raising the risk of asthma attacks, heart attacks and strokes, according to the University College London research team.
High pressure over the south‑east stopped the smoke from dispersing. “If we pop pollution into the atmosphere, whether that's from cars, industries, fireworks, or bonfires, that pollution doesn't go anywhere,” explained Liz Bentley, chief executive of Britain’s Royal Meteorological Society.
“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.
With the thick fog acting like a cap on the air, residents with asthma or heart disease are in particular danger. Public health officials warn that the lingering soot can cause breathing problems for those already vulnerable, and long‑term exposure may increase the number of heart attacks and strokes in the area.
Authorities are urging people to stay indoors while air quality remains high and to follow guidelines from local health services. The government has said it will monitor the situation closely after this year’s bonfire celebrations.
