ith organised firework displays banned because of Covid restrictions, people marked Guy Fawkes Night in their own gardens. The clear, still night on 5 November was ideal for being outside, but it was bad for air pollution. Smoke was slow to clear, and in many places it lingered until the following morning. Particle pollution across the Midlands reached the maximum UK index value of 10. London and cities in Yorkshire and across eastern England recorded pollution at index value of nine, a point where vulnerable people may experience breathing problems. Pollution increased over most of England and south Wales. Real-time chemical analysis at two field laboratories run by www.londonair.org.uk showed that the capital’s air was filled with particles from firework propellants and coloured sparkles. These included aluminium, potassium, strontium, copper, sulphur and chloride. Lead particles were also measured but peaked later in the evening, after the main firework chemicals. It is unclear if this came from fireworks or from lead-painted wood being burnt on bonfires. Firework chemicals were also in London’s air on the evening of 4 November, suggesting that some people brought forward their Guy Fawkes events to beat the new lockdown. Others waited until the 7th, especially in the north-west.