The air pollution data we collected over 24 hours last Bonfire Night paints a really striking picture.
Air pollution levels on Bonfire Night were up to four times the daytime level, scientists have said following a major urban study.
Thousands of sensors across Newcastle and Gateshead constantly take readings of fine particulate matter, and on November 5 last year they showed that measurements tripled between 8pm and midnight as bonfires and fireworks were lit.
Levels rose from around 20 micrograms/m3 during the day to 80 micrograms/m3 just before 11pm.
That figure compares with the annual average across the area of 25 micrograms/m3 and is eight times the World Health Organisation's recommended safe limit of 10 micrograms/m3.
The data was collected as part of Newcastle University's Urban Observatory, the UK's largest urban experiment collecting data about city life, taking in around 60 studies of everything from energy use, noise, rainfall, pollution, traffic and social media use.
Professor Phil James, from Newcastle University's School of Engineering, said: "The air pollution data we collected over 24 hours last Bonfire Night paints a really striking picture of the impact the fireworks and bonfires are having on air quality.
"It's perhaps not surprising - you can often smell the gunpowder and smoke in the air on November 5th - and the low cloud cover that night exacerbated the situation."
The wider study is aimed at observing how cities interact, and to help policymakers in the future to come up with solutions to urban problems.
The Department for Environment, Food and Rural Affairs (Defra) said pollution levels were not expected to remain high around Bonfire Night this year, with different weather conditions forecast from those experienced in 2018.
A Defra spokesman said: "Fireworks and bonfire celebrations can sometimes lead to temporarily increased levels of air pollution in localised areas, however we are expecting pollution levels to fall rapidly on Bonfire Night this year as the increased winds should disperse any particles."
Tom Wilkinson is a reporter with PA.